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CFR NPRM
 Federal Register Information
[Federal Register: May 28, 1964]
[Page 7050]
Header Information
DEPARTMENT OF TRANSPORTATION
Federal Aviation Agency
14 CFR Part 29
[Docket No. 5084; Notice No. 64-30]
Transport Category Rotorcraft
Preamble Information
AGENCY: Federal Aviation Administration, DOT
ACTION: Notice of Proposed Rulemaking
[14 CFR Parts 7, 29 [New]
SUMMARY: The Federal Aviation Agency is considering a proposal to recodify present Part 7 of the Civil Air Regulations into Part 29 [New].
SUPPLEMENTARY INFORMATION:
Interested persons are invited to participate in the proposed recodification by submitting such written data, views, or arguments as they may desire. Communications should identify the regulatory docket or notice number and be submitted in duplicate to the Federal Aviation Agency, Office of the General Council. Attention Rules Docket, 800 Independence Avenue SW., Washington, D.C., 20553. All communications received within 60 days after publication of this notice in the FEDERAL REGISTER will be considered by the Administrator before taking actin on the proposed recodification. The proposal contained in this notice may be changed in the light of comments received. All comments submitted will be available in the rules docket for examination by interested persons, both before and after the closing date for comments.
Proposed Part 29 [New] contains the airworthiness requirements for rotorcraft to be certificated in the transport categories. The procedural requirements of Part 7 are being transferred to proposed Part 21 [New].
The object of Part 29 [New] is to restate existing regulations, not to make new ones. The pertinent provisions have been freely reworded and rearranged, subject to every precaution against disturbing existing rights, privileges, duties or functions. In addition, in cases where well established administrative practice or construction has established authoritative interpretations, the revised language reflects the interpretations.
Each proposed recodified section is followed by a note citing the present section of the regulations upon which it is based. A cross-reference table has been placed at the end of Part 20 [New] to permit easy access from the old regulations to the new. Internal cross references to Parts or sections that are not yet recodified contain a blank space for later in section of the correct recodified number with the present number contained in brackets. When Part or section that is referred to in a cross reference is later recodified, the correct number will be inserted and the bracketed number will be dropped.
No substantive changes involving an increased burden on the public have been made in the regulations, the purpose of the recodification project being simply to streamline and clarify present regulatory language and to delete obsolete or redundant provisions. It should be noted that the definitions, abbreviations, and rules of construction contained in Part 1 [New] published in the FEDERAL REGISTER on May 15, 1962 (27 F.R. 4587 would apply to the proposed rules. In addition, those definitions in present Part 7 (and not now in Part 1 [New]) that are necessary, will be added to Part 1 [New] prior to the adoption of Part 29 [New].
Present CAR 7.306 requires that certain values contained in the publication ANC-17 be used for design purposes. This publication has been replaced with the publication MIL HDBK-17. This change is accordingly reflected in proposed FAR 29.263.
The material in present CAR 7.333 and in the note following present Sec. 7.332(a), containing an acceptable method for showing compliance with the limit drop test requirements when an effective mass is used for analysis, has been placed in proposed Appendix A.
Present CAR 7.116 requires the hovering performance of certain rotorcraft to be determined at a height above the ground consistent with the procedure used in establishing the "takeoff and accelerate-stop distance". No such distance, or related procedure, is specified in present Part 7. Established practice indicates that the procedure referred to is that used in establishing the takeoff climbout path and the rejected takeoff path. This practice is accordingly reflected in proposed Sec. 29.57, paragraph (a).
Present CAR 7.357 provides that flight crew emergency exits are not required on "small" rotorcraft if existing passenger emergency exits allow ready evacuation of the flight crew. In this context, the term "small" has little meaning other than to suggest a relationship between rotorcraft size and the accessibility of passenger emergency exits to the flight crew. Further, the definition of "small aircraft" in Part 1 [New] relates the term "small" to the sole criterion of weight. Ease of evacuation, not size or weight, is the test for compliance with the subject requirement. The term "small" is accordingly deleted in proposed Sec. 29.365, paragraph (b).
Preliminary study indicates that references to "miles" and "miles per hour" should be standardized in terms of nautical measurement. When this part is finally adopted, it is therefore proposed to use the terms "nautical mile" and "knot" where "mile" and "miles per hour" are now used. Nautical equivalents of existing values will be used, so that no increases in burden will result. Comment is specifically invited on this matter.
When finally adopted, Part 29 [New] will include the substance of any applicable rules or amendments adopted and made effective during the period between the date of notice and the effective date of the final rule, and may also include applicable rules on which individual notices of proposed rule making have been issued and the comment period has expired, but which have not been theretofore adopted.
Regulatory Information
The Proposed Amendment:
In consideration of the foregoing it is proposed to amend Chapter I of Title 14 of the Code of Federal Regulations by deleting present Part 7 and adding a Part 29 [New] reading as hereinafter set forth.
This proposal is made under the authority of sections 313(a), 601, and 603 of the Federal Aviation Act of 1958 (72 Stat. 752,775,776; 49 U.S.C. 1354(a), 1421, and 1423).
PART 29 -- AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT
Subpart A -- General
Sec.
29.1 Applicability.
Subpart B -- Flight
29.21 Proof of compliance.
29.28 Weight limitations.
29.25 Center of gravity limitations and loading instructions.
29.27 Main rotor speed and pitch limits.
29.29 Empty weight and corresponding center of gravity.
29.31 Removable ballast.
PERFORMANCE
29.41 General.
29.43 Limiting height-speed envelope.
29.45 Takeoff data; general.
29.47 Takeoff; category A.
29.49 Takeoff; category B.
29.51 Climb requirements; category A.
29.53 Climb requirements; category B.
29.55 Helicopter angle of glide; category B.
29.57 Performance at minimum operating speed.
29.58 Landing data; general.
29.59 Landing; category A.
29.61 Landing; category B.
FLIGHT CHARACTERISTICS
29.69 General.
29.71 Controllability and maneuverability
29.73 Trim control.
29.75 Stability.
GROUND AND WATER HANDLING CHARACTERISTICS
29.85 General.
29.87 Ground resonance.
29.89 Spry characteristics.
MISCELLANEOUS FLIGHT REQUIREMENTS
29.99 Vibration.
Subpart C -- Structure
GENERAL
29.121 Loads; factor of safety.
29.123 Strength and deformation.
29.125 Proof of structure.
29.127 Design limitations.
FLIGHT LOADS
29.137 General.
29.139 Flight load factor.
29.141 Maneuvering conditions.
29.143 Gust loads.
29.145 Yawing conditions.
CONTROL SURFACE AND SYSTEM LOADS
29.155 General.
29.157 Auxiliary rotor assemblies.
29.159 Auxiliary rotor attachment structure.
29.161 Ground clearance; tail rotor guard
29.163 Stabilizing and control surfaces.
29.165 Primary control system loads.
LANDING LOADS
29.175 General.
29.177 Level landing conditions.
29.179 Nose-up landing condition.
29.181 One wheel landing condition.
29.183 Lateral drift landing condition.
29.185 Braked roll conditions.
29.187 Taxiing conditions.
29.198 Ski landing conditions.
29.203 Float landing conditions.
29.205 Ground loading conditions; landing gear with tail wheels.
MAIN COMPONENT REQUIREMENTS
29.217 Main rotor structure.
29.219 Fuselage and rotor, pylon structures.
29.221 Auxiliary lifting surfaces.
29.229 Emergency landing conditions.
Subpart D--Design and Construction
GENERAL
29.251 Design.
29.253 Materials.
29.255 Fabrication methods.
29.257 Standard fastenings.
29.259 Protection of structure.
29.261 Inspection provisions.
29.263 Material strength properties and design values.
29.265 Special factors, tests, and inspection methods.
29.267 Casting factors.
29.269 Bearing factors.
29.271 Fitting factors.
29.273 Flutter.
MAIN ROTOR
29.281 Pressure venting and drainage of main rotor blades.
29.283 Stops.
29.285 Rotor and blade balance.
29.287 Rotor blade clearance.
CONTROL SYSTEMS
29.297 General.
29.299 Control system stops.
29.301 Control system locks.
29.303 Limit load static tests.
29.305 Operation tests.
29.307 Control system details.
29.309 Spring devices.
29.311 Autorotation control mechanism.
29.313 Power boost and power-operated control system.
LANDING GEAR
29.323 Shock absorption tests.
29.325 Retracting mechanism.
29.327 Wheels.
29.329 Brakes.
29.331 Tires.
29.333 Skis.
HULLS AND FLOATS
29.339 Buoyancy.
29.341 Float strength.
PERSONNEL AND CARGO ACCOMMODATIONS
29.351 Pilot compartments; general.
29.353 Pilot compartment visibility.
29.355 Pilot windshield and windows.
29.357 Cockpit controls.
29.359 Doors.
29.361 Seats, safety belts, and harnesses.
29.363 Cargo and baggage compartments.
29.365 Emergency evacuation.
29.367 Ventilation.
29.369 Heaters.
FIRE PREVENTION
29.377 General.
29.379 Cabin interiors.
29.381 Cargo and baggage compartments.
29.383 Combustion heater fire protection.
29.385 Fire protection of structure, controls, and other parts.
29.387 Flammable fluid fire protection.
MISCELLANEOUS
29.395 Leveling marks.
29.397 Ballast provisions.
29.399 Ice protection.
Subpart E--Powerplant Installation
GENERAL
29.421 General.
29.423 Engines.
29.425 Engine vibration.
ROTOR DRIVE SYSTEM
29.435 Rotor drive system
29.437 Rotor brake.
29.439 Rotor drive system and control mechanism test.
29.441 Additional tests.
29.443 Shafting critical speed.
29.445 Shafting joints.
FUEL SYSTEM
29.453 General.
29.455 Fuel system independence.
29.457 Fuel flow.
29.459 Unusable fuel supply.
29.461 Fuel system hot weather operation.
29.463 Flow between interconnected tanks.
FUEL TANK CONSTRUCTION AND INSTALLATION
29.473 General.
29.475 Fuel tank tests.
29.477 Fuel tank installation.
29.479 Fuel tank expansion space.
29.481 Fuel tank sump.
29.483 Fuel tank filler connection.
29.485 Fuel tank vents and carburetor vapor vents.
29.487 Fuel tank outlet.
29.489 Pressure refueling and fueling provisions below fuel level in the tank.
29.501 Fuel pumps.
29.503 Fuel pump installation.
29.505 Fuel system lines and fittings.
29.507 Valves.
29.509 Fuel strainer.
29.511 Drains.
29.513 Fuel quantity indicator.
OIL SYSTEM
29.523 General.
29.525 Oil tank construction.
29.527 Oil tank tests.
29.529 Oil tank installation.
29.531 Oil lines and fittings
29.533 Oil valves.
29.535 Oil radiators.
29.537 Oil filters.
29.539 Oil drains.
COOLING SYSTEM
29.551 General.
29.553 Cooling tests.
29.555 Climb cooling test procedures.
29.557 Takeoff cooling test procedures; category A.
29.559 Cooling test procedures; category B.
29.561 Hovering cooling test procedures.
INDUCTION AND EXHAUST SYSTEM
29.571 General.
29.573 Induction system icing protection.
29.575 Carburetor air preheater design.
29.577 Induction system ducts.
29.579 Induction system screens.
29.581 Carburetor air cooling.
29.583 Inter-coolers and after -coolers.
29.585 Exhaust system and installation components.
POWERPLANT CONTROLS AND ACCESSORIES
29.601 Powerplant controls; general.
29.603 Throttle and antidetonant injection system controls.
29.605 Ignition switches.
29.607 Mixture controls.
29.609 Carburetor air preheat controls.
29.611 Supercharger controls.
29.613 Rotor brake controls.
29.615 Powerplant accessories.
29.617 Engine ignition systems.
POWERPLANT FIRE PROTECTION
29.631 Designated fire zones; regions included.
29.633 Flammable fluids.
29.635 Shutoff means.
29.637 Lines and fittings.
29.639 Fire-extinguishing systems.
29.641 Fire-detector systems.
29.643 Firewall.
29.645 Engine cowling and engine compartment covering.
29.647 Drainage and ventilation of fire zones.
SUBPART F--EQUIPMENT
GENERAL
29.671 Scope.
29.673 Function and installation.
29.675 Required basic equipment.
29.677 Equipment, systems, and installations.
INSTRUMENTS; INSTALLATION
29.691 Arrangement and visibility.
29.693 Flight and navigation instruments.
29.695 Powerplant instruments.
ELECTRICAL SYSTEMS AND EQUIPMENT
29.705 Electrical system capacity.
29.707 Generating system.
29.709 Distribution system.
29.711 Electrical protection.
29.713 Electrical equipment and installations.
29.715 Electrical system fire and smoke protection.
29.717 Electrical system tests.
LIGHTS
29.727 Instrument lights.
29.729 Landing lights.
29.731 Position light system installation.
29.733 Position light system dihedral angles
29.735 Position light distribution and intensities.
29.737 Minimum intensities in the horizontal plane of forward and rear position lights.
29.739 Minimum intensities in any vertical plane of forward and rear position lights.
29.741 Maximum intensities in overlapping beams of forward and rear position lights.
29.743 Color specifications.
29.745 Riding light.
29.747 Anticollision light system.
SAFETY EQUIPMENT
29.761 Accessibility.
29.763 Flares.
29.765 Safety belts; passenger warning device.
29.767 Emergency flotation and signaling equipment.
29.769 Stowage of safety equipment.
29.771 Protective breathing equipment; oxygen supply.
MISCELLANEOUS EQUIPMENT
29.781 Hydraulic systems; strength.
29.783 Hydraulic systems; design
29.785 Hydraulic systems; fire protection.
29.787 Radio installation.
29.789 Vacuum systems.
Subpart G--Operating Limitations and Information
GENERAL
29.811 Operating limitations and information.
OPERATING LIMITATIONS
29.821 Airspeed limitations; general.
29.823 Never-exceed speed Vns.
29.825 Operating speed range.
29.827 Rotor speed.
29.829 Powerplant limitations.
29.831 Limiting height-speed envelope.
29.832 Weight and center of gravity.
29.833 Minimum flight crew.
29.835 Limitations on operation.
29.837 Maintenance manual.
MARKINGS AND PLACARDS
29.847 General.
29.849 Instrument markings; general.
29.851 Airspeed indicator.
29.853 Magnetic direction indicator.
29.855 Powerplant instruments.
29.857 Oil quantity indicator.
29.859 Fuel quantity indicator.
29.861 Control markings.
29.863 Miscellaneous markings and placards.
ROTORCRAFT FLIGHT MANUAL
29.873 General.
29.875 Operating limitations.
29.877 Operating procedures.
29.879 Performance information.
Appendix A--Limit drop tests.
Subpart A--General
Section 29.1 Applicability.
(a) This part prescribes airworthiness standards for the issue of, and changes to, type and supplemental type certificates for ---
(1) Multiengine rotorcraft that meet the requirements for transport category A;
(2) Rotorcraft with maximum weights of 20,000 pounds or less that meet the requirements for transport category B; and
(3) Multiengine rotorcraft that meet the requirements for transport category A or B.
(b) Each person who applies under Part 21 [New] for a certificate or change described in paragraph (a) of this section must show compliance with all applicable requirements in this part.
[Revision note: Paragraph (a) combines Secs. 7.0 (1st sentence) and 7.20 (a) and (b) (1st sentence); paragraph (b) supplied]
Subpart B--Flight
Sec. 29.21 Proof of compliance.
(a) Each requirement of this subpart must be complied with at each appropriate combination of weight and center of gravity within the range of loading conditions for which certification is requested. This must be shown--
(1) By tests upon a rotorcraft of the type for which certification is requested, or by calculations based on, and equal in accuracy to, the results of testing; and
(2) By systematic investigation of all required combinations of weight and center of gravity, if compliance cannot be reasonably inferred from combinations investigated.
(b) The controllability, stability, and trim of the rotorcraft must be shown for all altitudes up to the maximum expected in operation.
[Revision note: Based on Sec. 7.100(a) through (c)]
Sec. 29.23 Weight limitations.
(a) Maximum weight. The maximum weight, that is the greatest weight for which compliance with every applicable requirement of this part is shown, or, at the option of the applicant, the greatest weight for each altitude and for each practically separable operating condition, such as takeoff, en route operation, and landing, must be established so that it is not greater than--
(1) The weight selected by the applicant;
(2) The design maximum weight, that is, the greatest weight for which compliance with every applicable structural loading condition of this part is shown; or
(3) The greatest weight at which compliance with every applicable flight requirement is shown.
(b) Minimum weight. The minimum weight, that is, the lowest weight for which compliance with every applicable requirement of this part is shown, must be established so that it is not less than--
(1) The lowest weight selected by the applicant;
(2) The design maximum weight, that is, the greatest weight for which compliance with every applicable structural loading condition of this part is shown; or
(3) The greatest weight at which compliance with every applicable flight requirement is shown.
[Revision note: Based on Sec. 7.101]
Sec. 29.25 Center of gravity limitations and loading instructions.
(a) A limit rearward and a limit forward center of gravity must be established for each weight established under Sec. 29.23. No such limit may lie beyond--
(1) The extremes selected by the applicant;
(2) The extremes for which the structure is proven; or
(3) The extremes for which compliance with all applicable flight requirements is shown.
(b) Loading instructions must be provided for each possible loading condition between the maximum and minimum weights specified in Sec. 29.23 that can result in a center of gravity beyond any limit prescribed in paragraph (a) of this section, assuming all probable occupant weights.
[Revision note: Based on Sec. 7.102]
Sec. 29.27 Main rotor speed and pitch limits.
(a) Main rotor speed limits. A range of main rotor speeds must be established that ----
(1) With power on, provides adequate margin to accommodate all variations in rotor speed occurring in all appropriate maneuvers, and is consistent with the kind of governor or synchronizer used; and
(2) With power off, allows all appropriate authoritative maneuvers to be performed throughout all ranges of airspeed and weight for which certification is requested.
(b) Main rotor pitch limits. The range of main rotor pitch settings must be limited as follows:
(1) A means must be provided so that the normal high pitch limit, with full throttle, does not result in rotor speeds substantially less than the minimum approved for any sustained flight condition. This means need not be provided, however, if----
(i) The inherent characteristics of the rotorcraft make it unnecessary; or
(ii) Adequate means are provided to warn the pilot of unsafe main rotor speeds.
(2) With power off, the low pitch limit must---
(i) Provide rotor speeds within the approved range for all autorotative conditions under the most critical combinations of weight and airspeed; and
(ii) Allow the pilot, without exceptional skill, to prevent overspeeding of the rotor.
(c) Emergency high pitch. A main rotor pitch higher than the normal high pitch limit prescribed in paragraph (b) (1) of this section may be made available for emergency use if the normal high pitch limit cannot be exceeded inadvertently.
[Revision note: Based on Sec. 7.108]
Sec. 29.29 Empty weight and corresponding center of gravity.
(a) The empty weight and corresponding center of gravity must be determined by weighing the rotorcraft without the weight of crew and payload, but with the weight of
(1) All fixed ballast;
(2) All unusable fuel;
(3) All undrainable oil;
(4) All engine coolant; and
(5) All hydraulic fluid.
(b) The condition of the rotorcraft when weighed under paragraph (a) of this section must be easily reproducible and well defined, particularly with respect to the weights of fuel, oil coolant, and installed equipment.
[Revision note: Based on Sec. 7.104]
Sec. 29.31 Removable ballast.
Removable ballast may be used in showing compliance with the flight requirements of this part.
[Revision note: Based on Sec 7.105]
PERFORMANCE
Sec. 29.41 General.
(a) The performance prescribed in this subpart must be determined----
(1) With normal piloting skill;
(2) Without exceptionally favorable conditions; and
(3) With each powerplant accessory absorbing the normal amount of power for the flight condition being investigated.
(b) Compliance with the performance requirements of this subpart must be shown---
(1) In still air at sea level with a standard atmosphere;
(2) For the range of atmospheric variables selected by the applicant; and
(3) Where engine power affects performance, with air at 80 percent relative humidity, or 0.7" Hg. vapor pressure, whichever is less.
[Revision note: Based on Sec. 7.110 (less note following)]
Sec. 29.43 Limiting height-speed envelope.
(a) If there is any combination of height and forward speed (including hover) under which a safe landing cannot be made under the applicable power failure condition in paragraph (b) of this section, a limiting height-speed envelope must be established for that condition.
(b) The applicable power failure conditions are--
(1) For category A rotorcraft, sudden failure of the critical engine, with the remaining engines at takeoff power;
(2) For category B rotorcraft, complete power failure; and
(3) For multiengine, category B rotorcraft for which certification under the powerplant installation requirements of category A is requested, condition as in subparagraph (1) or (2) of this paragraph.
[Revision note: Based on Sec. 7.111]
Sec. 29.45 Takeoff data; general.
(a) All takeoff data required by Secs. 29.47 (b) and (c), 29.49, and 29.51 (a) and (b) must be determined---
(1) At all weights, altitudes, and temperatures selected by the applicant; and
(2) With the operating engines within approved limitations.
(b) All takeoff data, when corrected, must---
(1) Assume a level takeoff surface; and
(2) Be determined---
(i) On a smooth, dry, hard surface; and
(ii) So that reproduction of performance does not require exceptional piloting skill or alertness, or exceptionally favorable conditions.
[Revision note: Based on Sec. 7.112 (less (a))]
Sec. 29.47 Takeoff; category A.
(a) General. The takeoff performance must be determined and scheduled so that, if one engine fails at nay time after the start of takeoff, the rotorcraft can---
(1) Return to, and stop safely on, the takeoff area; or
(2) Continue the takeoff and climbout, and attain a configuration and airspeed allowing compliance with Sec. 29.51 (b).
(b) Critical decision point. The critical decision point must be a combination of height and speed selected by the applicant in establishing the flight paths under paragraph (c) of this section. The critical decision point must be obtained so as to avoid the critical areas of the limiting height-speed envelop established under Sec. 29.43.
(c) Takeoff climbout path and rejected takeoff path. The takeoff climbout path, and the rejected takeoff path must be established so that the takeoff, climbout, and rejected takeoff are accomplished with a safe, smooth transition between all stages of the maneuver. The takeoff may begun in any manner if the takeoff surface is defined and adequate safeguards are maintained to ensure proper center of gravity and control positions. In addition, the following rules apply:
(1) The rejected takeoff path must be established with takeoff power on all engines from the start of takeoff to the critical decision point, at which point it must be assumed that the critical engine becomes inoperative, and that the rotorcraft is brought to a safe stop with the remaining engines operating within approved limitations.
(2) The takeoff climbout path must be established with takeoff power on all engines from the start of takeoff to the critical decision point, at which point it must be assumed that the critical engine becomes inoperative. with the remaining engines operating within their approved limitations, the rotorcraft must be accelerated to the takeoff safety speed by the end of the rejected takeoff distance, and the climbout must be accomplished--
(i) At not less than the takeoff safety speed used in meeting the rate of climb specified in Sec. 29.51(a); and
(ii) So that the airspeed and configuration used in meeting the climb requirement of Sec. 29.51(b) are attained.
[Revision note: Combines Secs. 7.112(a), 7.113, and 7.11(4)]
Sec. 29.49 Takeoff; category B.
The takeoff and climbout must be established with the most unfavorable center of gravity. the takeoff may be begun in any manner if---
(a) The takeoff surface is defined;
(b) Adequate safeguards are maintained to ensure proper center of gravity and control positions; and
(c) A landing can be made safely at any point along the flight path in an engine fails.
[Revision note: based on Sec. 7.114 )less (a))]
Sec. 29.51 Climb requirements; category A.
Each category A rotorcraft must meet the following takeoff and en route climb requirements:
(a) Takeoff climb. The steady rate of climb without ground effect must be at least 100 feet per minute for each weight, altitude, and temperature condition for which takeoff data are to be scheduled, with---
(1) The critical engine inoperative and the remaining engines operating within approved limitations;
(2) The most unfavorable center of gravity for takeoff;
(3) The landing gear extended;
(4) The speed selected by the applicant; and
(5) Cowl flaps or other means of controlling the engine-cooling air supply in the position that provides adequate cooling at the temperatures and altitudes for which certification is requested.
(b) Climb at maximum continuous power. The steady rate of climb without ground effect must be at least 150 feet per minute for each weight, altitude, and temperature condition for which takeoff data are to be scheduled, with---
(1) The critical engine inoperative and the remaining engines at maximum continuous power;
(2) The most unfavorable center of gravity for takeoff;
(3) The landing gear retracted;
(4) The speed selected by the applicant; and
(5) Cowl flaps or other means of controlling the engine-cooling air supply in the position that provides adequate cooling at the temperatures and altitudes for which certification is requested.
(c) En route climb. The steady rate of climb in feet per minute at any altitude at which the rotorcraft is expected to operate, and at any weight within the range of weights for which certification is requested, must be determined with---
(1) The critical engine inoperative, and the remaining engines at the maximum continuous power available at each altitude;
(2) The most unfavorable center of gravity;
(3) The landing gear retracted;
(4) The speed selected by the applicant; and
(5) Cowl flaps or other means of controlling the engine-cooling air supply in the position that provides adequate cooling at the temperatures and altitudes for which certification is requested.
[Revision note: Based on Sec. 7.115 (less (b))]
Sec. 29.53 Climb requirements; category B.
(a) The steady rate of climb at Vy must be determined for each category B rotorcraft--
(1) With maximum continuous power on all engines and the landing gear retracted; and
(2) Over the range of weights, altitudes, and temperatures for which certification is requested.
(b) For each category B rotorcraft except helicopters, the rate of climb determined under paragraph (a) must provide a steady climb gradient of at least 1:6 under standard sea level conditions.
(c) For multiengine category B helicopters complying with the requirements for category A rotorcraft in Sec. 29.43, the steady rate of climb or decent must be determined at the speed for best rate of climb (or minimum rate of descent) with one engine inoperative and the remaining engines at maximum continuous power.
[Revision note: Based on Sec. 7.115(b) (less (3))]
Sec. 29.55 Helicopter angle of glide; category B.
For each category B helicopter, the steady angle of glide must be determined in autorotation
(a) At the maximum and minimum rates of descent;
(b) At maximum weight; and
(c) With the optimum forward speed.
[Revision note: Based on Sec. 7.115(b) (3)]
Sec. 29.57 Performance at minimum operating speed.
(a) For each category A rotorcraft, the hovering performance must be determined over the range of weight, altitudes, and temperatures for which takeoff data are scheduled---
(1) With not more than takeoff power on all engines;
(2) With the landing gear extended; and
(3) At a height consistent with the procedure used in establishing the take-off climbout and rejected takeoff paths.
(b) For each category B helicopter--
(1) The hovering performance must altitude, and temperature for which certification is requested, with---
(i) Takeoff power on all engines;
(ii) The landing gear extended; and
(iii) The helicopter in the ground effect at a height consistent with normal takeoff procedures; and
(2) The hovering ceiling determined under subparagraph (1) of this paragraph must be at least 4,000 feet at maximum weight with a standard atmosphere.
(c) For rotorcraft other than helicopters, the steady rate of climb at the minimum operating speed must be determined, over the range of weights, altitudes, and temperatures for which certification is requested, with--
(1) Takeoff power; and
(2) The landing gear extended.
[Revised note: based on Sec. 7.116]
Sec. 29.58 Landing data; general.
(a) All corrected landing data must---
(1) Assume a level landing surface; and
(2) Be determined on a smooth, dry, hard surface.
(b) The approach and landing must be made so that its reproduction does not require exceptional piloting skill or exceptionally favorable conditions.
(c) During the landing, there may be no excessive vertical acceleration and no tendency to bounce, nose over ground loop, porpoise, or water loop.
(d) The landing data required by Secs. 29.59 (b) and (c), and 26.61 must be determined---
(1) At all weights, altitudes, and temperatures selected by the applicant; and
(2) With all operating engines within approved limitations.
[Revision note: Based on Sec. 7.117 (less (a))]
Sec. 29.59 Landing; category A.
(a) General. For each category A rotorcraft, the landing performance must be determined and scheduled so that, if one engine fails at any point in the approach path, the rotorcraft can land and stop safely, or climb out from a point in the approach path and attain a rotorcraft configuration and speed allowing compliance with the climb requirement of Sec. 29.51 (b).
(b) One engine inoperative. the approach, balked landing, and landing paths must be established, with one between each stage can be made smoothly and safely. The approach and landing speeds must be selected by the applicant and must be appropriate to the type of rotorcraft. In addition, the following rules apply:
(1) The approach and landing path must be established to avoid the critical areas of a limiting height-speed envelope established---
(i) Under Sec. 29.43; or
(ii) Under the landing condition with one engine inoperative.
(2) The balked-landing path must be established so that, from a combination of height and speed in the approach path selected by the applicant, a safe climbout can be made at speeds allowing compliance with the climb requirements of Sec. 29.51 (a) and (b).
(c) Complete power failure. It must be possible to make a safe landing on a prepared runway after complete power failure during normal cruise. The maximum allowable rate of descent in autorotation must be determined.
[Revision note: Combines Secs. 7.117(a) and 7.118(a) and (b)]
Sec. 29.61 Landing; category B.
(a) Autorotative landing. For each category B rotorcraft, the horizontal distance required to land and come to a complete stop (or to a speed of approximately three m.p.h. for water landings) from a point 50 feet above the landing surface, must be determined with---
(1) Glide speeds appropriate to the type of rotorcraft and chosen by the applicant; and
(2) The approach and landing must be made with power off and entered from steady autorotation.
(b) Optional requirements for multiengine rotorcraft. Each multiengine category B rotorcraft that conforms with the powerplant installation requirements of category A must conform with---
(1) Paragraph (a) of this paragraph; or
(2) Section 29.59 (b) and (c), omitting the climbout requirement of Sec. 29.59 (b) (2).
[Revision note: based on Sec. 7.118 (less (a) and (b))]
FLIGHT CHARACTERISTICS
Sec. 29.69 General.
The rotorcraft must---
(a) Conform with this section and Secs. 29.71 through 29.75 at all normally expected operating altitudes, under all critical loading conditions within the range of weights and centers of gravity for which certification is requested, and under all conditions of speed, power and rotor r.p.m. for which certification is requested;
(b) Be able to maintain any required flight condition and make a smooth transition from any flight condition to any other flight condition without exceptional piloting skill, alertness or strength, and without danger of exceeding the limit load factor under all operating conditions probable for the type, including sudden powerplant failure; and
(c) Have all additional characteristics required by the Administrator for night or instrument operation, if certification for such operation is requested.
[Revision note: Based on Sec. 7.120]
Sec. 29.71 Controllability and maneuverability.
(a) The rotorcraft must be safely controllable and maneuverable---
(1) During steady flight; and
(2) During all maneuvers appropriate to the type, including---
(i) Takeoff;
(ii) Climb;
(iii) Level flight;
(iv) Turning flight;
(v) Glide; and
(vi) Landing (power on and power off).
(b) The margin of cyclic control must allow satisfactory roll and pitch control--
(1) At VNE with---
(i) Maximum weight;
(ii) Critical center of gravity;
(iii) Critical rotor r.p.m.; and
(iv) Power on and power off; and
(2) At VH or VNE whichever is less, with---
(i) Failure of power; and
(ii) Conditions as in subdivisions (i) through (iii) of subparagraph (1).
(c) A maximum wind velocity of not less than 20 miles per hour must be established in which the rotorcraft can be operated without loss of control on or near the ground in any maneuver appropriate to the type (such as crosswind takeoffs, sideward flight, and rearward flight), with---
(1) Critical center of gravity; and
(2) Critical rotor r.p.m.
(d) The rotorcraft, after power failure, must be controllable over the range of speeds and altitudes for which certification is requested, when the power failure occurs under maximum continuous power and critical weight. No corrective action time delay for any condition following power failure may be less than---
(1) For the cruise condition, one second, or normal pilot reaction time (whichever is greater); and
(2) For any other condition, normal pilot reaction time.
[Revision note: Based on Sec. 7.121]
Sec. 29.73 Trim control.
The trim control---
(a) Must trim all steady longitudinal and lateral control forces to zero with the rotorcraft in level flight at any speed appropriate to the type; and
(b) May not introduce any undesirable discontinuities in control force gradients.
[Revision note: Based on Sec. 7.122]
Sec. 29.75 Stability.
(a) General. It must be shown that the rotorcraft can be flown, without undue pilot fatigue or strain, in all normal maneuvers for a period of time as long as that expected in normal operation. At least three landings and takeoffs must be performed during this demonstration.
(b) Static longitudinal stability. The longitudinal cyclic control must be designed so that, for the ranges of altitude and rotor r.p.m. for which certification is requested, and with throttle and collective pitch held constant during the maneuvers specified in paragraphs (c) and (d) of this section---
(1) A rearward movement of the control is necessary to obtain airspeeds less than the trim speed; and
(2) A forward movement of the control is necessary to obtain airspeeds greater than the trim speed.
However, the stick position versus speed curve may have a negative slope within the speed ranges specified for each maneuver in paragraph (c) of this section if the necessary negative stick displacement is not greater than ten percent of the total stick travel.
(c) Test maneuvers. The following maneuvers must be performed:
(1) Climb at all speeds from 0.85 Vy to 1.2 Vy with---
(i) Critical weight;
(ii) Critical center of gravity;
(iii) Maximum continuous power;
(iv) The landing gear retracted; and
(v) The rotorcraft trimmed for Vy .
(2) Cruise at all speeds from 0.7 VH or 0.7 VNE whichever is less to 1.1 VH or 1.1 VNE whichever is less, with --
(i) Critical weight;
(ii) Critical center of gravity;
(iii) Power for level flight at 0.9 VH or VNE whichever is less.
(iv) The landing gear retracted; and
(v) The rotorcraft trimmed for 0.9 VH or VNE whichever is less.
(3) Autorotation throughout the speed range for which certification is requested, with---
(i) Critical weight;
(ii) Critical center of gravity;
(iii) Power off;
(iv) The landing gear (a) retracted and (b) extended; and
(v) The rotorcraft trimmed for the speed for minimum rate of descent.
(d) Hovering. for helicopters---
(1) In the hovering condition, the longitudinal cyclic control must operate with the sense and direction of motion prescribed in paragraph (b) of this section; and
(2) The stick position curve must have a stable slope between the maximum approved rearward speed and a forward speed of 20 miles per hour, with---
(i) The determined hovering weight (for category 4 helicopters), or critical weight (for other rotorcraft);
(ii) Critical center of gravity;
(iii) Power required for hovering in still air;
(iv) The landing gear retracted; and
(vi) The helicopter trimmed for hovering.
[Revision note: Based on Sec. 7.123]
GROUND AND WATER HANDLING CHARACTERISTICS
Sec. 29.85 General.
The rotorcraft must have satisfactory ground and water handling characteristics, including freedom from all uncontrollable tendencies in all conditions expected in operation.
[Revision note: Based on Sec. 7.130]
Sec. 29.87 Ground resonance.
The rotorcraft, when on the ground, may not have any dangerous tendency to oscillate with the rotor turning.
[Revision note: Based on Sec. 7.131]
Sec. 29.89 Spray characteristics.
If certification for water operation is requested, no spray characteristics during taxiing, takeoff, or landing may obscure the vision of the pilot or damage the rotors, propellers, or other parts of the rotorcraft.
[Revision note: Based on Sec. 7.132]
MISCELLANEOUS FLIGHT REQUIREMENTS
Sec. 29.99 Vibration.
Each part of the rotorcraft must be free from excessive vibration under all appropriate conditions of speed and power.
[Revision not: Based on Sec. 7.140 (vibration aspect)]
Subpart C--Structure
General
Sec. 29.121 Loads; proof of compliance.
(a) Strength requirements are specified in terms of limit loads and ultimate loads. Unless otherwise provided, all specified loads are limit loads.
(b) Unless otherwise provided, the specified air, ground, and water loads must be placed in equilibrium with inertia forces, considering all items of mass in the rotorcraft. These loads must be distributed in a manner closely approximating or conservatively representing actual conditions.
(c) If deflections under load would significantly change the distribution of external or internal loads, this redistribution must be taken into account.
(d) Unless otherwise specified, factor of safety of 1.5 must be used. This factor applies to external and inertia loads unless its application to the resulting internal stresses is more conservative.
[Revision note: Based on Sec. 7.200]
Sec. 29.123 Strength and deformation.
(a) The structure must be able to support limit loads without detrimental, permanent deformation. At all loads up to limit loads, the deformation may not interfere with safe operation of the rotocraft.
(b) The structure must be able to support ultimate loads without failure. this must be shown by---
(1) Applying ultimate loads to the structure in a static test for at least three seconds; or
(2) Dynamic tests simulating actual load application.
[Revision note: Based on Sec. 7.201]
Sec. 29.125 Proof of structure.
(a) Compliance with the strength and deformation requirements of this subpart must be shown for all critical loading conditions. Structural analysis may be used only if the structure conforms to those for which experience has shown this method to be reliable. In all other cases, substantiating load tests must be made.
(b) Proof of compliance with the strength requirements of this subpart must include---
(1) Dynamic and endurance tests of rotors, rotor drives, and rotor controls;
(2) Limit load tests of the control system, including control surfaces;
(3) Operation tests of the control system;
(4) Flight stress measurement tests;
(5) Landing gear shock absorption tests; and
(6) For each new or unusual design feature, all additional tests required by the Administrator.
[Revision note: Combines Secs. 7.202 (less (c)) and 7.203]
The following values and limitations must be established to show compliance with the structural requirements of this subpart:
(a) The design maximum and minimum weights.
(b) The main rotor r.p.m. ranges, power on and power off.
(c) The maximum forward speeds for each main rotor r.p.m. within the ranges determined under paragraph (b) of this section.
(d) The maximum rearward and sideward flight speeds.
(e) The center of gravity limits corresponding to the limitations determined under paragraphs (b), (c), and (d) of this section.
(f) The rotational speed ratios between each powerplant and each connected rotating component.
(g) The positive and negative limit maneuvering load factors.
[Revision note: Based on Sec. 7.204]
FLIGHT LOADS
Sec. 29.137 General.
Compliance with the flight load requirements of this subpart must be shown---
(a) At all weights from the design minimum weight to the design maximum weight; and
(b) With any practical distribution of disposable load within the operating limitations in the rotorcraft flight manual.
[Revision note: Based on Sec. 7.310]
Sec 29.139 Flight load factor.
The flight load factor must be assumed to act normal to the longitudinal axis of the rotorcraft, and to be equal in magnitude and opposite in direction to the rotorcraft inertia load factor at the center of gravity.
[Revision note: Based on Sec. 7.211]
(a) Limit maneuvering load factors. The rotorcraft must be able to withstand----
(1) A positive limit maneuvering load factor of 3.5 and a negative limit maneuvering load factor of 1.0; or
(2) Any lesser positive limit maneuvering load factor not less than 2.0, and lesser negative limit maneuvering load factor not less than 0.5, for which---
(i) The probability of being exceeded is shown by analysis and flight tests to be extremely remote; and
(ii) The selected values are appropriate to each design weight condition between the design maximum and design minimum weights.
(b) Resultant limit maneuvering loads. All loads resulting form the application of limit maneuvering load factors must be assumed to act at the center of each rotor hub and at each auxiliary lifting surface, and to act in directions and with distributions of load among the rotors and auxiliary lifting surfaces so as to represent all critical maneuvering motions, including power-on and power-off flight with the maximum design rotor tip speed ratio. The rotor tip speed ratio is the ratio of the rotorcraft flight velocity component in the plane of the rotor disc to the rotational tip speed of the rotor blades, and is expressed as follows:
where---
V=The airspeed along the flight path (f.p.s.);
a=The angle between the projection, in the plane of symmetry, of the axis of no feathering and a line perpendicular to the flight path (radians, positive when axis is pointing aft);
 =The angular velocity of rotor (radians per second); and
R=The rotor radius (ft.).
[Revision note: Combines Secs. 7.212 and 7.1 (h) (5)]
Sec. 29.143 Gust loads.
Each rotorcraft must be designed to withstand, at all critical airspeeds including hovering, all loads resulting from vertical and horizontal gusts of 30 feet per second.
[Revision note: Based on Sec. 7.213]
Sec. 29.145 Yawing conditions.
(a) Each rotorcraft must be designed for all loads resulting from the maneuver specified in paragraph (b) of this section, with--
(1) All unbalanced aerodynamic moments about the center of gravity reacted in a rational or conservative manner considering the principal masses furnishing the reacting inertia forces:
(2) Maximum main rotor speed; and
(3) All forward speeds up to VNE or VH whichever is less.
(b) With the rotorcraft in unaccelerated flight at zero yaw, it must be assumed that--
(1) The cockpit directional control is suddenly displaced to the maximum deflector, limited by the control stops or by maximum pilot effort;
(2) The rotorcraft then yaws to a resulting sideslip angle; and
(3) The directional control is then suddenly returned to neutral.
[Revision note: Based on Sed. 7214]
CONTROL SURFACE AND SYSTEM LOADS
Sec. 29.155 General.
Each auxiliary rotor, fixed or movable stabilizing or control surface, and each system operating any flight control must meet the requirements of Secs. 29.157 through 29.165.
[Revision note: Based on Sec. 7.220]
Sec. 29.157 Auxiliary rotor assemblies.
(a) All auxiliary rotor assemblies. Each auxiliary rotor assembly must be tested as prescribed in Sec. 29.439.
(b) Assemblies with detachable blades. Each auxiliary rotor assembly with detachable blades must be able to withstand all centrifugal loads resulting from the maximum design rotor r.p.m.
(c) Highly stressed metal components. For each auxiliary rotor with highly stressed metal components, all vibration stresses must be determined in flight and shown not to exceed safe values for continuous operation.
[Revision note: Based on Sec. 7.221]
Sec. 29.159 Auxiliary rotor attachment structure.
The attachment structure for each auxiliary rotor must be designed to withstand a limit load equal to the maximum loads occurring in the structure in all flight and landing conditions.
[Revision note: Based on Sec. 7.222]
Sec. 29.161 Ground clearance; tail rotor guard.
(a) It must be impossible for the tail rotor to contact the landing surface during a normal landing.
(b) If a tail rotor guard is required to show compliance with paragraph (a) of this section---
(1) Suitable design loads must be established for the guard; and
(2) The guard and its supporting structure must be designed to withstand all loads established under subparagraph (1) of this paragraph.
[Revision note: Based on Sec. 7.223]
Sec. 29.163 Stabilizing and control surfaces.
(a) Each stabilizing and control surface must be designed so that---
(1) Limit loads are not less than the greater of---
(i) 15 pounds per square foot; or
(ii) The load resulting where CN equals 0.55 at the maximum design speed; and
(2) The surface can withstand all critical loads resulting from maneuvers and from combined maneuvers and gusts.
(b) Compliance with paragraph (a) of this section must be shown with load conditions that closely simulate actual pressure distribution conditions.
[Revision note: based on Sec. 7.224]
Sec. 29.165 Primary control system loads.
(a) General. Each primary control system, including its supporting structures, must be able to withstand the following loads:
(1) All loads resulting from application of the limit pilot forces prescribed in paragraph (d) of this section.
(2) The maximum loads that can be obtained in normal operation, including the effects of any single power-boost system failure.
(3) Loads that ensure a rugged system for service use, considering the effects of fatigue, jamming, ground gust, control inertia, and friction. In the absence of a rational analysis, loads resulting from the application of 0.60 of the limit pilot forces prescribed in paragraph (b) of this section are acceptable for this purpose.
(b) Limit pilot forces. The limit pilot forces are as follows:
(1) For foot controls, 130 pounds.
(2) For stick controls, 100 pounds fore and aft, and 67 pounds laterally, a couple of 53 D inch-pounds (where D is the wheel diameter).
(c) Reaction to limit pilot loads. The reaction to the loads prescribed in paragraph (b) must be provided by---
(1) The control stops only;
(2) The control locks only:
(3) The irreversible mechanism only (with the mechanism locked and with the control surface in all critical positions for the affected portions of the system within its limit of motion);
(4) The attachment of the control system to the rotor blade pitch control horn only (with the control in all critical positions for the affected portions of the system within the limits of its motion); and
(5) The attachment of the control system to the control surface horn (with the control in all critical positions for the affected portions of the system within the limits of its motion).
(d) Dual primary flight control systems. Each dual primary flight control system must be able to withstand all loads that result when pilot loads not less than 0.75 times those obtained under paragraph (b) of this section are applied ---
(1) In opposition; and
(2) In the same direction.
[Revision noted: Combines Secs. 7.225 and 7.226]
LANDING LOADS
Sec. 29.175 General
(a) Loads and equilibrium. For limit landing loads---
(1) All limit landing loads obtained in the landing conditions in this part must be considered to be external loads that would occur in the rotorcraft structure if it were acting as a rigid body; and
(2) In each specified landing condition, all external loads must be placed in equilibrium with all linear and angular inertia loads in a rational or conservative manner.
(b) Critical center of gravity. All critical centers of gravity within the range for which certification is requested must be selected so that the maximum design loads are obtained in each landing gear element.
(c) Design maximum weight; assumed rotor lift. For all specified landing conditions, a design maximum weight must be used that is not less than the maximum weight. A rotor lift may be assumed to act through the center of gravity throughout the landing impact. This lift may not exceed---
(1) Two-thirds of the design maximum weight; or
(2) An greater lift proven to be appropriate by tests or other data that are applicable to the particular rotorcraft.
(d) Limit load factor. for each specified landing condition, the rotorcraft must be designed for a limit load factor of not less than the limit inertia load factor substantiated in accordance with Sec. 29.323, unless other wise prescribed.
(e) Tires and shock absorbers. For each specified landing condition, the tires must be assumed to be in their static position and the shock absorbers to be in their most critical position, unless otherwise prescribed.
(f) Landing gear arrangement. sections 29.177 through 29.187 apply to landing gears with two wheels aft, and one or more wheels forward, of the center of gravity.
[Revision note: Based on Sec. 7.230]
Sec. 29.177 Level landing conditions.
(a) Attitudes. Under each of the loading conditions prescribed in paragraph (b) of this section, the rotorcraft must be assumed to be in each of the following level landing attitudes;
(1) An attitude in which all wheels contact the ground simultaneously.
(2) An attitude in which the aft wheels contact the ground with the forward wheels just clear of the ground.
(b) Loading conditions. The rotorcraft must be designed for the following landing loading conditions:
(1) Vertical loads applied in accordance with Sec. 29.175.
(2) All loads resulting from a combination of the loads applied under subparagraph (1) of this paragraph with drag loads at each wheel of not less than 25 percent of the vertical load at that wheel.
(3) The vertical load at the instant of peak drag load combined with a drag component simulating the forces required to accelerate the wheel rolling assembly up to the specified ground speed, with---
(i) The ground speed for determination of the spin-up loads being at least 75 percent of the optimum forward flight speed for minimum rate of descent in autorotation; and
(ii) The landing conditions of this subparagraph applied to the landing gear and its attaching structure only.
(4) If there are two wheels forward, a distribution of all loads applied to those wheels under subparagraph (1) and (2) of this paragraph in a ratio of 40:60.
(c) Pitching moments. All pitching moments must be assumed to be resisted by---
(1) In the case of attitude as in paragraph (a) (1), the forward landing gear; and
(2) In the case of attitude as in paragraph (a) (2), the angular inertia forces.
[Revision note: Based on Sec. 7.231]
Sec. 29.179 Nose-up landing condition.
(a) The rotorcraft must be assumed to be in the maximum nose-up attitude allowing ground clearance by all parts of the rotorcraft.
(b) In this attitude, all ground loads must be assumed to act perpendicular to the ground.
[Revision note: Based on Sec. 7.282]
Sec. 29.181 One wheel landing condition.
The rotorcraft must be assumed to be in the level attitude and to contact the ground on one aft wheel. In this attitude--
(a) The vertical load must be the same as that obtained on that side under Sec. 29.177 (b) (1); and
(b) All unbalanced external loads must be reacted by rotorcraft inertia.
[Revision note: Based on Sec. 7.233]
Sec. 29.183 Lateral drift landing condition.
(a) The rotorcraft must be assumed to be in the level landing attitude, with---
(1) Side loads combined with one-half the maximum ground reactions obtained in the level landing conditions of Sec. 29.177 (b) (1); and
(2) All loads obtained under subparagraph (1) of this paragraph applied--
(i) At the ground contact point; or
(ii) For full-swiveling gear, at the center of the axle.
(b) The rotorcraft must be designed to withstand, at round contact--
(1) When only the aft wheels contact the ground, side loads of 0.8 times the vertical reaction acting inward on one side and 0.6 times the vertical reaction acting outward on the other side, all combined with the vertical loads specified in paragraph (a) of this section; and
(2) When all wheels contact the ground simultaneously--
(i) For the aft wheels, the side loads specified in subparagraph (1) of this paragraph; and
(ii) For the forward wheels, a side load of 0.8 times the vertical reaction combined with the vertical load specified in paragraph (a) of this section.
[Revision note: Based on Sec. 7.234]
Sec. 29.185 Braked roll conditions.
Under braked roll conditions with the shock absorbers in their static positions--
(a) The limit vertical load must be based on a load factor of at least--
(!) 1.33, for the attitude specified in Sec. 29.177 (a) (1); and
(2) 1.0, for the attitude specified in Sec. 29.177 (a) (2); and
(b) The structure must be designed to withstand the application, at the ground contact point of each wheel with brakes, of a drag load of not less than the lesser of---
(1) The vertical load multiplied by a coefficient of friction of 0.8; and
(2) The maximum value based on limiting brake torque.
[Revision note: Based on Sec. 7.235]
Sec. 29.187 Taxiing condition.
The rotorcraft must be designed to withstand all loads that would occur when the rotorcraft is taxied over the roughest ground that may reasonably be expected in normal operation.
[Revision note: Based on Sec. 7.236]
Sec. 29.193 Ski landing conditions.
If certification for ski operation is requested, the rotorcraft, with skis, must be designed to withstand the following load conditions (where P is the maximum static weight on each ski with the rotorcraft at design maximum weight, and n is the limit load factor determined in accordance with Sec. 29.175 (d)):
(a) Up-load conditions in which---
(1) A vertical load of Pn and a horizontal load of Pn/4 are simultaneously applied at the pedestal bearings; and
(2) A vertical load of 1.33 P is applied at the pedestal bearings.
(b) A side load condition in which a side load of 0.35Pn is applied at the pedestal bearings in a horizontal plane perpendicular to the centerline of the rotorcraft.
(c) A torque-load condition in which a torque load of 1.33P (in foot pounds) is applied to the ski about the vertical axis through the centerline of the pedestal bearings.
[Revision note: based on Sec. 7.240]
Sec. 29.203 Float landing conditions.
If certification for float operation is requested, the rotorcraft, with floats, must be designed to withstand the following loading conditions (where the limit load factor is determined under Sec. 29.175(d) or assumed to be equal to that determined for wheel landing gear):
(a) Up-loading conditions in which--
(1) A load is so applied that, with the rotorcraft in the static level attitude, the resultant water reaction passes vertically through the center of gravity; and
(2) The vertical load prescribed in subparagraph (1) of this paragraph is applied simultaneously with an aft component of 0.25 times the total vertical component.
(b) A side load condition in which--
(1) A vertical load of 0.75 times the total vertical load specified in subparagraph (a) (1) of this section is divided equally among the floats; and
(2) For each float, the load share determined under subparagraph (1) of this paragraph, combined with a total side load of 0.25 times the total vertical load specified in subparagraph (b) (1) of this section, is applied to that float only.
[Revision note: Based on Sec. 7.245]
Sec. 29.205 Ground loading conditions; landing gear with tail wheels.
(a) General. Rotorcraft with landing gear with two wheels forward and one wheel aft of the center of gravity must be designed for all loading conditions as prescribed in this section.
(b) Level landing attitude with only the forward wheels contacting the ground. In this attitude---
(1) All vertical loads must be applied under Sec. 29.175;
(2) The vertical load at each axle must be combined with a drag load at that axle of not less than 25 percent of that vertical load; and
(3) All unbalanced pitching moments must be assumed to be resisted by angular inertia forces.
(c) Level landing attitude with all wheels contacting the ground simultaneously. In this attitude, the rotorcraft must be designed for all landing loading conditions as prescribed in paragraph (b) of this section.
(d) Maximum nose-up attitude with only the rear wheel contacting the ground. The attitude for this condition must be the maximum nose-up attitude expected in normal operation, including autorotative landings. In this attitude--
(1) The appropriate ground loads specified in paragraph (b) (1) and (2) of this section must be determined and applied, using a rational method to account for the moment arm between the rear wheel ground reaction and the rotorcraft center of gravity; or
(2) The probability of landing with initial contact on the rear wheel must be shown to be extremely remote.
(e) Level landing attitude with only one forward wheel contacting the ground. In this attitude, the rotorcraft must be designed for ground loads as specified in paragraph (b) (1) and (3) of this section.
(f) Side loads in the level landing attitude. In the attitudes specified in paragraphs (d) and (c) of this section, the following rules apply:
(1) All side loads must be combined at each wheel with one-half of the maximum vertical ground reactions obtained for that wheel under paragraphs (b) and (c) of this section. In this condition, the side loads must be--
(i) For the forward wheels, 0.8 times the vertical reaction ( on one side) acting inward, and 0.6 times the vertical reaction (on the other side) acting outward; and
(ii) For the rear wheel, 0.8 times the vertical reaction.
(2) The loads specified in subparagraph (1) of this paragraph must be applied--
(i) At the ground contact point with the wheel in the trailing position, (for non-full swiveling landing gear with a lock, steering device, or shimmy damper to keep the wheel in the trailing position): or
(ii) At the center of the axle, (for full swiveling landing gear which do not have a lock, steering device, or shimmy damper).
(g) Braked roll conditions in the level landing attitude. In the attitudes specified in paragraphs (b) and (c) of this section, and with the shock absorbers deflected to their static positions, the rotorcraft must be designed for braked roll loads as follows:
(1) The limit vertical load must be based on a limit load factor of not less than --
(i) 1.0, for the attitude specified in paragraph (b) of this section; and
(ii) 1.33, for the attitude specified in paragraph (c) of this section.
(2) For each wheel with brakes, a drag load must be applied, at the ground contact point, of not less than the lesser of---
(i) 0.8 times the vertical load: and
(ii) The maximum based on limiting brake torque.
(h) Rear wheel turning loads in the static ground attitude. In the static ground attitude, and with the shock absorbers and tires deflected to their static positions, the rotorcraft must be designed for rear wheel turning loads as follows:
(1) A vertical ground reaction equal to the static load on the rear wheel must be combined with an equal side load.
(2) The load specified in subparagraph (1) of this paragraph must be applied to the rear landing gear--
(i) Through the axle, when a swivel is provided (the rear wheel being as summed to be swiveled 90 degrees to the longitudinal axis of the rotorcraft); or
(ii) At the ground contact point, when a lock, steering device or shimmy damper is provided (the rear wheel being assumed to be in the trailing position).
(1) Taxiing condition. The rotorcraft and its landing gear must be designed for all loads that would occur when the rotorcraft is taxied over the roughest ground that may reasonably be expected in normal operation.
[Revision note: based on Sec. 7.246]
MAIN COMPONENT REQUIREMENTS
Sec. 29.217 Main rotor structure.
(a) Each main rotor assembly (including rotor hubs and blades) must be designed as prescribed in this section.
(b) All hubs, blades, blade attachments, and blade controls subject to alteration stress must be designed to withstand all repeated loading conditions likely to occur within their established service lives. In addition--
(1) The stresses of critical parts must be determined in flight in all attitudes appropriate to the type of rotorcraft throughout the ranges of limitations prescribed in Sec. 29.127; and
(2) The service life of each critical part must be established by the applicant on the basis of----
(i) Fatigue tests; or
(ii) Any other approved method.
(c) The main rotor structure must be designed to withstand the following loads prescribed in Secs. 29.137 through 29.145;
(1) Critical flight loads.
(2) Limit loads occurring under all normal conditions of autorotation.
(d) The main rotor structure must be designed to withstand loads simulating---
(1) For the rotor blades, hubs, and flapping hinges, the impact force of each blade against its stop during ground operation; and
(2) All other critical conditions expected in normal operation.
(e) The main rotor structure must be designed to withstand the design limit torque at all rotational speeds, including zero. In addition:
(1) The design limit torque need not be greater than the torque defined by a torque limiting device (where provided), and must not be less than the greater of ----
(i) The maximum torque likely to be transmitted to the rotor structure, in either direction, by the rotor drive or by sudden application of the rotor brake; and
(ii) The design limit engine torque specified in Sec. 29.219(d).
(2) The design limit torque must be equally and rationally distributed to the rotor blades.
[Revision note: based on Sec. 7.250]
Sec. 29.219 fuselage and rotor pylon structure must be designed to withstand---
(1) The critical loads prescribed in Secs. 29.137 through 29.145;
(2) The applicable ground loads prescribed in Secs. 29.175 through 29.023; and
(3) The loads prescribed in Sec. 29.217 (d) (1) and (e) (1) (i).
(b) Auxiliary rotor thrust, the torque reaction of each rotor drive system, and all balancing air and inertia loads occurring under accelerated flight conditions, must be considered.
(c) Each engine mount and adjacent fuselage structure must be designed to withstand all loads occurring under accelerated flight and landing conditions, including engine torque.
(d) The design limit engine torque may not be less than---
(1) For turbine engines, the mean torque for maximum continuous power multiplied by a factor of 1.25; and
(2) For reciprocating engines, the mean torque multiplied by---
(i) 1.33, for engines with five or more cylinders; and
(ii) Two, three, and four, for engines with four, three, and two cylinders, respectively.
(e) For critical parts, that is, parts whose sudden failure would threaten the structural integrity of the rotorcraft, the following rules apply:
(1) Each part must be designed to withstand all repeated loading conditions likely to occur within its established service life.
(2) Stresses on parts must be determined in flight---
(i) For all attitudes appropriate to the type of rotorcraft; and
(ii) For each attitude, throughout the ranges of limitations prescribed in Sec. 29.127.
(3) The service life of each part must be established by the applicant on the basis of---
(i) Fatigue tests; or
(ii) Any other approved method.
[Revision note: Based on Sec. 7.251]
Sec. 29.221 Auxiliary lifting surfaces.
Each auxiliary lifting surface must be designed to withstand---
a) The critical flight loads in Secs. 29.137 through 29.145;
(b) The applicable ground loads in Secs. 29.175 through 29.203; and
(c) All other critical conditions expected in normal operation.
[Revision note: Based on Sec. 7.252]
Sec. 29.229 Emergency landing conditions.
(a) The rotorcraft, although it may be damaged in emergency landing conditions on land or water, must be designed a s prescribed in this section to protect all occupants under those conditions.
(b) The structure must be designed to give all occupants every reasonable chance of escaping serious injury in a minor crash landing when---
(1) Proper use is made of seats, belts, and all other safety design provisions;
(2) The wheels are retracted (where applicable); and
(3) All occupants experience the following ultimate inertia forces relative to the surrounding structure:
(i) Upward -- 1.5g.
(ii) Forward -- 4.0g.
(iii) Sideward -- 2.0g.
(iv) Downward -- 4.0g, or any lesser force that will not be exceeded when the rotorcraft absorbs the landing loads resulting form impact with an ultimate decent velocity of five f.p.s. at design maximum weight.
(c) The supporting structure must be designed to restrain, under all loads up to those specified in paragraph (b) (3) of this section, all items of mass that could injure an occupant if they came loose in a minor crash landing.
(d) All fuselage structure in the area of internal fuel tanks below the passenger floor level must be designed to resist all crash impact loads specified in this section, and to protect the fuel tanks from rupture, if rupture is likely when those loads are applied to that area.
[Revision note: Combines Secs. 7.260 and 7.261 (less note following)]
Subpart D -- Design and Construction
GENERAL
Sec. 29.251 Design.
(a) The rotorcraft may have no design features or details known to be hazardous or unreliable.
(b) The suitability of all questionable design details and parts must be established by tests.
[Revision note: Based on Sec. 7.300]
Sec. 29.253 Materials
The suitability and durability of all materials used in the structure must--
(a) Be established on the basis of experience or tests; and
(b) Conform to approved specifications that ensure their having the strength and other properties assumed in the design data.
[Revision note: Based on Sec. 7.301]
Sec. 29.255 Fabrication methods.
(a) All methods of fabrication must produce a consistently sound structure.
(b) When compliance with paragraph (a) of this section requires close control of any fabrication process (such as gluing, spot welding, or heat treating), that process must be performed under approved process specifications.
[Revision note: based on Sec. 7.302]
Sec. 29.257 Standard fastenings.
Each bolt, pin, screw, and rivet used in the structure must be approved.
(b) Each bolt, pin, and screw used in the structure must use an approved locking device or method.
(c) No self-locking nut may be used on any bolt subject to rotation.
[Revision note: Based on Sec. 7.308]
Sec. 29.259 Protection of structure.
Each part of the rotorcraft structure must----
(a) Be suitably protected against deterioration or loss of strength in service due to any cause, including---
(1) Weathering;
(2) Corrosion; and
(3) Abrasion; and
(b) Have provisions for ventilation and drainage where necessary to prevent the accumulation of corrosive, flammable, or noxious fluids.
[Revision note: Based on Sec. 7.304]
Sec. 29.261 Inspection provisions.
Means must be provided to allow the close examination of all parts of the rotocraft that require---
(a) Periodic inspection;
(b) Adjustment for proper alignment and functioning; or
(c) Lubrication (for moving parts).
[Revision note: Based on Sec. 7.305]
Sec. 29.263 Material strength properties and design values.
(a) All material strength properties must be based on a sufficient number of tests of material conforming to approved specifications to establish design values on a statistical basis;
(b) All design values must be so chosen that the probability of nay structure being understength because of material variations is extremely remote;
(c) The strength, detail design, and fabrication of the structure must minimize the probability of disastrous fatigue failure, particularly at points of stress concentration;
(d) Unless they are shown to be inapplicable in a particular case, all design values must be those contained in the following publications (which are published by the Department of Defense and the Federal Aviation Agency and may be obtained from the Superintendent of Documents, Government Printing Office, Washington, D.C., 20401):
MIL-HDBK-5, "Metallic Materials and Elements for Flight Vehicle Structure".
MIL-HDBK-17, "Plastics for Flight Vehicles".
ANC-18, "Design of Wood Aircraft Structure".
IL-HDBK-23, "Composites Construction for Flight Vehicles".
[Revision note: Based on Sec. 7.306]
Sec. 29.265 Special factors, tests, and inspection methods.
(a) The special factors prescribed in Secs. 29.267 through 29.271 apply to each part of the rotorcraft structure whose strength is---
(1) Uncertain;
(2) Likely to deteriorate in service prior to normal replacement; or
(3) Subject to appreciable variability due to---
(i) Uncertainties in manufacturing processes; or
(ii) Uncertainties in inspection methods.
(b) For each part of the rotorcraft to which Secs. 29.267 through 29.271 apply the factor of safety prescribed in Sec. 29.121 (d) must be multiplied by a special factor equal to--
(1) The applicable special factors prescribed in Secs. 29.267 through 29.271; or
(2) Any other factor great enough to ensure that the probability of the part being understrength because of the uncertainties specified in paragraph (a) of this section is extremely remote.
[Revision note: Based on Sec. 7.307 (a)]
Sec. 29.267 Casting factors.
(a) General. The factors, tests, and inspections specified in paragraphs (b) and (c) of this section must be applied in addition to those necessary establish foundry quality control. The inspections must meet approved specifications. Paragraphs (c) and (d) of this section apply to all structural casting except castings that are pressure tested as parts of hydraulic or other fluid systems and do not support structural loads.
(b) Bearing stresses and surfaces. The casting factors specified in paragraphs (c) and (d) of this section---
(1) Need not exceed 1.25 with respect to bearing stresses regardless of the method of inspection used; and
(2) Need not be used with respect to the bearing surfaces of a part whose bearing factor is larger than the applicable casting factor.
(c) Critical castings. For each casting whose failure would preclude continued safe flight and landing of the rotorcraft or result in serious injury to occupants, the following rules apply:
(1) Each critical casting must---
(i) Have a casting factor of not less than 1.25; and
(ii) Receive 100 percent inspection by visual, radiographic, and magnetic particle (for ferromagnetic material) or penetrate (for nonferromagnetic materials) inspection methods or approved equivalent inspection methods.
(2) For each critical casting with a casting factor less than 150, three sample castings must be static tested and shown to conform with---
(i) The strength requirements of Sec. 29.123 at an ultimate load corresponding with a casting factor of 1.25; and
(ii) The deformation requirements of Sec. 29.123 at a load of 1.15 times the limit load.
(d) Noncritical castings. For each casting other than those specified in paragraph (c) of this section, the following rules apply:
(1) Except as provided in subparagraphs (2) and (3) of this paragraph, the casting factors and corresponding inspections must conform to the following table:
Casting factor Inspection for each casting
| 2.0 or greater---- | 100 percent visual. |
| Less than 2.0, greater than 1.5. | 100 percent visual, and magnetic particle (ferromagnetic materials), Penetrate (non ferromagnetic material), or approved equivalent inspection methods, |
| 1.25 to 1.50 inclusive. | 100 percent visual, and magnetic particle ferromagnetic materials), Penetrate (nonferromagnetic materials), and radiographic or approved equivalent inspection methods. |
(2) The percentage of castings inspected by nonvisual methods may be reduced below that specified in subparagraph (1) of this paragraph when an approved quality control procedure established.
(3) For castings procured to a specification that guarantees the mechanical properties of the material in the casting and provides for demonstration of these properties by test of coupons cut from the castings on a sampling basis--
(i) A casting factor of 1.0 may be used; and
(ii) The castings must be inspected as provided in subparagraph (1) of this paragraph for casting factors of "1.25 to 1.50 inclusive" and tested in accordance with paragraph (c) (2) of this section.
[Revision note: Based on Sec. 7.307 (b)]
Sec. 29.269 Bearing factors.
(a) Except as provided in paragraph (b) of this section, each part that has clearance (free fit), and that is subject to pounding or vibration, must have a bearing factor large enough to provide for the efforts of normal relative motion.
(b) No bearing factor need be used on a part for which any larger special factor is prescribed.
[Revision note: Based on Sec. 7.307(c)]
Sec. 29.271 Fitting factors.
For each fitting, that is part or terminal used to join one structural member to another, the following rules apply:
(a) For each fitting whose strength is not proven by limit and ultimate load tests in which actual stress conditions are simulated in the fitting and surrounding structures, a fitting factor of at least 1.15 must be applied to all portions of--
(1) The fitting;
(2) The means of attachment; and
(3) The bearing on the joined members.
(b) No fitting factor need be used--
(1) For joints made in accordance with approved practices and based on comprehensive test data (such as continuous joints in metal plating, welding joints, and scarf joints in wood); and
(2) With respect to any bearing surface for which a larger special factor is used.
(c) For each integral fitting, the part must be treated as a fitting up to the point at which the section properties become typical of the member.
[Revision note: Based on Sec. 7.307 (less (a) through (c) )]
Sec. 29.273 Flutter.
Each part of the rotorcraft must be free from flutter under all appropriable conditions of speed and power.
[Revision note: Based on Sec. 7.140 (less vibration aspect)]
MAIN ROTOR
Sec. 29.281 Pressure venting and drainage of main rotor blades.
For each main rotor blade---
(a) Means must be provided for venting the internal pressure of the blade;
(b) Drainage holes must be provided for the blade; and
(c) The blade must be designed to prevent water form becoming trapped in any section of the blade.
[Revision note: Based on Sec. 7.310]
Sec. 29.233 Stops.
For each main rotor blade---
(a) The blade must have stops, appropriate to the design, to limit its travel about its hinges; and
(b) Provision must be made to keep the blade form hitting the droop stops during all operations other than the starting and stopping of the rotor.
[Revision note: Based on Sec. 7.311]
Sec. 29.285 Rotor and blade balance.
The rotor and blades must be mass balanced as necessary to---
(a) Prevent excessive vibration; and
(b) Prevent flutter at all speeds up to the maximum forward speed.
[Revision note: Based on Sec. 7.312]
Sec. 29.287 Rotor blade clearance.
Sufficient clearance must be provided, between the main rotor blades and all other parts of the structure, to prevent the blades from striking any part of the structure during any operating condition.
[Revision note: Based on Sec. 7.313]
CONTROL SYSTEMS
Sec. 29.297 General.
(a) Each control and control system must operate with the ease, smoothness, and positiveness appropriate to its function.
(b) Each element of each flight control system must be designed, or distinctively and permanently marked, to minimize the probability of incorrect assembly that could result in the malfunctioning of the system.
[Revision note: based on Sec. 7.320]
Sec. 29.299 Control system stops.
(a) Each control system must have stops that positively limit the range of motion of the pilot's controls.
(b) Each stop must be so located in the system that the range of travel of its control is not appreciably affected by---
(1) Wear;
(2) Slackness; or
(3) Take-up adjustments.
(c) Each stop must be able to withstand all loads corresponding to the design conditions for the system.
[Revision note: Based on Sec. 7.321]
Sec. 29.301 Control system locks.
If a device is provided of locking the control system with the rotorcraft on the ground or water, means must be provided to---
(a) Automatically disengage the lock when the pilot operates the controls in a normal manner, or limit the operation of the rotorcraft so as to give unmistakable warning to the pilot prior to takeoff; and
(b) Prevent the lock form becoming engaged in flight.
[Revision note: Based on Sec. 7.322]
Sec. 29.303 Limit load static test.
Compliance with the limit load requirements of this Part must be shown in tests in which--
(a) The direction of the test loads produces the most severe loading in the control system;
(b) All fittings, pulleys, and brackets used in attaching the system to the main structure are included: and
(c) Compliance is shown (by analyses or individual load tests) with the special factor requirements for control system joints subject to angular motion.
[Revision note: based on Sec. 7.323]
Sec. 29.305 Operation tests.,
(a) When the controls are operated form the pilot compartment with the system loaded to correspond with the system loaded to correspond with loads specified for the system, the system must be free from--
(1) Jamming;
(2) Excessive friction; and
(3) Excessive deflection.
(b) Compliance with paragraph (a) of this section must be shown in actual tests.
[Revision note: Based on Sec. 7.324]
Sec. 29.307 Control system details.
(a) All details of each control system must be designed to prevent jamming, chafing, and interference form cargo, passengers, or loose objects.
(b) Means must be provided in the cockpit to prevent the entry of foreign objects into places where they would jam the system.
(c) Provision must be made to prevent the slapping of cables or tubes against other parts.
(d) Cable systems must be designed as follows:
(1) Cables, cable fittings, turnbuckles, splices, and pulleys must be approved.
(2) The design of cable systems must prevent any hazardous change in cable tension throughout the range of travel under all operating conditions and temperature variations.
(3) No cable smaller than 1/8 inch diameter may be used in any primary control system.
(4) All pulley kinds and sizes must correspond to the cables with which they are used. The pulley-cable combinations and strength values specified in MIL-HDBK-5 must be used unless shown to be inapplicable.
(5) All pulleys must have close fitting guard to prevent the cables from being displaced or fouled.
(6) All pulleys must lie close enough to the plane passing through the cable to prevent the cable from rubbing against the pulley flange.
(7) No fairleads may cause a change in cable direction of more than three degrees.
(8) No clevis pin subject to load or motion and retained only by cotter pins may be used in the control system
(9) All turnbuckles attached to parts having angular motion must be installed to prevent binding throughout the range of travel.
(10) Provision for visual inspection must be made at all fairleads, pulleys terminals, and turnbuckles.
(e) Control system joints subject to angular motion must incorporate the following special factors with respect to the ultimate bearing strength of the softest material used as a bearing;
(1) 3.33 for push-pull systems other than ball and roller bearing systems.
(2) 2.0 for cable control systems.
(f) For control system joints, the manufacture's static, non-Brinell rating of ball and roller bearings may not be exceeded.
[Revision note: Based on Sec. 7.325]
Sec. 29.309 Spring devices.
(a) Each control system spring device whose failure could cause flutter or other unsafe characteristics must be reliable.
(b) Compliance with paragraph (a) of this section must be shown in tests simulating service conditions.
[Revision note: Based on Sec. 7.326]
Sec. 29.311 Autorotation control mechanism.
Each main rotor blade pitch control mechanism must allow rapid entry into autorotation after power failure.
[Revision note: Based on Sec. 7.327]
Sec. 29.313 Power boost and power-operated control system.
(a) When a power boost or power-operated control system is used, an alternate system must be immediately available that allows the rotorcraft to be flown and landed safely in the event of---
(1) Any single failure in the power portion of the system; or
(2) The failure of all engines.
(b) Each alternate system may be a duplicate power portion or a manually operated mechanical system. The power portion must include the power source (such as hydraulic pumps), and such items as valves, lines, and actuators.
(c) The failure of mechanical parts (such as piston rods and links), and the jamming of power cylinders, must be considered unless they are shown to be extremely improbable.
[Revision note: Based on Sec. 7.328]
LANDING GEAR
Sec. 29.323 Shock absorption tests.
(a) General. The landing inertia load factor and the reserve energy absorption capacity of the landing gear must be substantiated by conducting the test prescribed in paragraphs (b) and (c) of this section, respectively. These tests must be conducted on the complete rotorcraft or on units consisting of wheel, tire, and shock absorber in their proper relation.
(b) Limit drop test. The limit drop test must be conducted as follows:
(1) The drop height must be---
(i) 13 inches from the lowest point of the landing gear to the ground; or
(ii) Any lesser height, not less than height inches, resulting in a drop contact velocity equal to the greatest probable sinking speed likely to occur at ground contact in normal power-off landings.
(2) If considered, the rotor lift specified in Sec. 29.175(c) must be introduced into the drop test by the use of appropriate energy absorbing devices or by the use of an effective mass. When effective mass is used, the method of computation specified in Appendix A of this part may be used instead of more rational computations.
(3) Each landing gear unit must be tested in the attitude simulating the landing condition that is most critical from the standpoint of the energy to be absorbed by that unit.
(c) Reserve energy absorption drop test. The reserve energy absorption drop test must be conducted as follows:
(1) The drop height must be 1.5 times that specified in paragraph (b)(1) of this section.
(2) Rotor lift, where considered in a manner similar to that prescribed in paragraph (b)(2) of this section.
(3) The landing gear must withstand this test without collapse.
[Revision note: Based on Sec. 7.382 (less note following (a))]
Sec. 29.325 Retracting mechanism.
(a) General. The landing gear, retracting mechanism, wheel well doors, and supporting structure, must be designed---
(1) For the loads occurring in all maneuvering conditions with the gear retracted;
(2) For the combination of friction, inertia, and air loads occurring during retraction and extension at all airspeeds up to the design maximum landing gear operating speed; and
(3) To withstand all flight loads, including those in yawed flight, occurring with the gear extended at all airspeeds up to the design maximum landing gear extended speed.
(d) Landing gear lock. A positive means must be provided to keep the gear extended.
(c) Emergency operation. When other than manual power is used to operate the gear, emergency means must be provided for extending the gear in the event of---
(1) Any reasonably probable failure in the normal retraction system; or
(2) The failure of any single source of hydraulic, electric, or equivalent energy.
(d) Operation tests. The proper functioning of the retracting mechanism must be shown by operation tests.
(e) Position indicator. Means must be provided for indicating to the pilot when the gear is secured in the extended and in the retracted positions.
(f) Control. The location and operation of the retraction control must meet the provisions of Sec. 29.357.
[Revision note: Based on Sec. 7.334]
Sec. 29.327 Wheels.
(a) Each landing gear wheel must be approved.
(b) The maximum static load rating of each wheel may not be less than the corresponding static ground reaction with--
(1) Maximum weight; and
(2) Critical center of gravity.
(c) The maximum limit load rating of each wheel must equal or exceed the maximum radial limit load determined under the applicable ground load requirements of this part.
[Revision note: Based on Sec. 7.335]
Sec. 29.329 Brakes.
A braking device must be installed that is---
(a) Controllable by the pilot;
(b) Usable during power-off landings: and
(c) Adequate to---
(1) Counteract any normal unbalanced torque when starting or stopping the rotor; and
(2) Hold the rotorcraft parked on a 10 degree slope on a dry, smooth pavement.
[Revision note: Based on Sec. 7.336]
Sec. 29.331 Tires.
(a) Each landing gear wheel must have a tire---
(1) That is a proper fit on the rim of the wheel; and
(2) Whose approved tire rating is not exceeded.
(b) Compliance with paragraph (a) (2) of this section must be shown with---
(1) Design maximum weight;
(2) A load on each main wheel tire equal to the static ground reaction corresponding to the critical center of gravity; and
(3) A load on nose wheel tires (to be compared with the dynamic rating established for those tires) equal to the reaction obtained at the nose wheel, assuming the mass of the rotorcraft to act at the most critical center of gravity and to exert a force of 1.0g downward and 0.25 g forward, the reactions being distributed to the nose and main wheels according to the principles of statics with the drag reaction at the ground applied only at wheels with brakes.
[Revision note: Based on Sec. 7.337]
Sec. 29.333 Skis.
(a) The maximum limit load rating of each ski must equal or exceed the maximum limit load determined in accordance with the applicable ground load requirements of this part.
(b) A stabilizing means must be provided to maintain the ski in an appropriate position during flight. This means must have sufficient strength to withstand the maximum aerodynamic and inertia loads to which the ski is subjected.
[Revision note: based on Sec. 7.338]
HULLS AND FLOATS
Sec. 29.339 Buoyancy.
(a) Main floats. For main floats--
(1) The buoyancy necessary to support the maximum weight of the rotorcraft in fresh water must be exceeded by---
(i) 50 percent, for single floats; and
(ii) 60 percent, for multiple floats; and
(2) Each main float must have at least five watertight compartments approximately equal in volume.
(b) Hulls and auxiliary floats. For each rotorcraft, with a hull and auxiliary floats, that is to be approved for both taking off from and landing on water, the hull and auxiliary floats must have watertight compartments such that, with any single compartment flooded, the buoyancy of the hull and auxiliary floats (and wheel tires if used) provide a margin of positive stability sufficient to minimize the probability of capsizing.
[Revision note: Based on Sec. 7.340]
Sec. 29.341 Float strength.
(a) Bag floats. Each bag float must be able to withstand--
(1) The maximum pleasure differential that might be developed at the maximum altitude for which certification with that float is requested; and
(2) The vertical loads prescribed in Sec. 29.203(a), distributed along the length of the bag over three-quarters of its projected area.
(b) Rigid floats. Each rigid float must be able to withstand the vertical, horizontal, and side loads prescribed in Sec. 29.203. An appropriate load distribution under critical conditions must be used.
[Revision note: Based on Sec. 7.341]
PERSONNEL AND CARGO ACCOMMODATIONS
Sec. 29.351 Pilot compartments; general.
For each pilot compartment--
(a) The arrangement of the compartment and its appurtenances must allow each pilot to perform all of his duties without unreasonable concentration and fatigue;
(b) When provision is made for a second pilot, the rotorcraft must be controllable with equal safety from both seats;
(c) The vibration and noise characteristics of cockpit appurtenances may not interfere with safe operation;
(d) Inflight leakage of rain or snow that could distract the crew or harm the structure must be prevented;
(e) A passageway must be provided between he pilot compartment and the passenger compartment; and
(f) Suitable means must be provided to prevent passengers from entering the pilot compartment without permission.
[Revision note: Based on Sec. 7.350]
Sec. 29.353 Pilot compartment visibility.
(a) Nonprecipitation conditions. For nonprecipitation conditions, the following rules apply:
(1) Each pilot compartment must be arranged to give the pilots a sufficiently extensive, clear, and undistorted view for safe operation.
(2) Each pilot compartment must be free of glare and reflection that could interfere with the pilot's view. If certification for night operation is requested, this must be shown in night flight tests.
(b) Precipitation conditions. For precipitation conditions, the following rules apply:
(1) Each pilot must have a sufficiently extensive view for safe operation---
(i) In heavy rain at forward speeds up to VH; and
(ii) In the most severe icing condition for which certification is requested.
(2) The pilots must have a window that---
(i) Is openable under the conditions prescribed in subparagraph (1); and
(ii) Provides the view prescribed in that subparagraph.
[Revision note: Based on Sec. 7.351]
Sec. 29.355 Pilot windshield and windows.
Nonsplintering safety glass must be used in all pilot windshields and windows.
[Revision note: Based on Sec. 7.352]
Sec. 29.357 Cockpit controls.
Cockpit controls must be--
(a) Located to provide convenient operation and to prevent confusion and inadvertent operation; and
(b) So located and arranged with respect to the pilot's seats that there is full and unrestricted movement of each control without interference form the cockpit structure of the pilot's clothing when pilots from 5'2" to 6'0" in height are seated.
[Revision note: Based on Sec. 7.353]
Sec. 29.359 Doors.
(a) Each closed cabin must have at least on e adequate and easily accessible external door.
(b) No passenger door may be located with respect to any rotor disc so as to endanger persons following appropriate instructions for the use of that door.
(c) Means must be provided for locking crew and external passenger doors and for preventing their opening in flight inadvertently or as a result of mechanical failure. It must be possible to open external doors form inside and outside the cabin with the rotorcraft on the ground. The means of opening must be simple, obvious, and so arranged and marked that it can be readily located and operated.
(d) Reasonable provisions must be made to prevent the jamming of any external door, in a minor crash, as a result of fuselage deformation.
(e) Means must be provided for a direct visual inspection of the locking mechanism by crewmembers to determine whether all external doors (including passenger, crew, service, and cargo doors) are fully locked. Visual means must be provided to signal to appropriate crewmembers when all normally used external doors are closed and fully locked.
(f) For outward opening external doors usable for entrance or egress, an auxiliary safety latching device must provided to prevent the door form opening when the primary latching mechanism fails. If the door does not meet the requirements of paragraph (c) of this section with this device in place, suitable operating procedures must be established to prevent the use of the device during takeoff and landing.
[Revision note: Based on Sec. 7.354]
Sec. 29.361 Seats, safety belts, and harnesses.
(a) General. For seats, safety belts, and shoulder harnesses---
(1) Each station designated for occupancy during takeoff and landing, and each seat, belt, harness, and adjacent part of the rotorcraft must be such that a person making proper use of these facilities will not suffer serious injury in an emergency landing as a result of inertia forces specified in Sec. 29.229(b); and
(2) All seats must be approved.
(b) Arrangement. Seats, belts, and harnesses must be arranged as follows:
(1) All occupants must be protected from head injury by---
(i) A belt and harness that will prevent the head from contacting any injurious object;
(ii) A belt plus the elimination of all injurious objects within striking radius of the head; or
(iii) A belt plus a cushioned rest that will support the arms, shoulders, head, and spine;
(2) For arrangements that do not provide a firm handhold on seat backs, hand grips or rails must be provided along each aisle to enable the occupants to steady themselves while using the aisle in moderately rough air; and
(3) Each projecting object that would injure persons seated or moving about in the rotorcraft in normal flight must be padded.
(c) Strength. Each seat and its supporting structure must be designed for a weight of 170 pounds, considering the maximum load factors, inertia forces, and all reactions between the occupant, seat, and belt or harness corresponding with all applicable flight and ground load conditions, including the emergency landing conditions of Sec. 29.229. In addition---
(1) Each pilot seat must be designed for all reactions resulting form the application of the pilot forces prescribed in Sec. 29.165; and
(2) The inertia forces prescribed in Sec. 29.229(b) must be multiplied by a factor of 1.33 in determining the strength of the attachment of--
(i) Each seat to the structure; and
(ii) Each belt or harness to the seat or structure.
[Revision note: Based on Sec. 7.355]
Sec. 29.363 Cargo and baggage compartments.
(a) Each cargo and baggage compartment must be designed for its placarded maximum weight of contents and for all critical load distributions at the appropriate maximum load factors corresponding with all specified flight and ground load conditions, except the emergency landing conditions of Sec. 29.229.
(b) Provision must be made to prevent the contents in any compartment from becoming a hazard by shifting under the loads specified in paragraph (a) of this section.
(c) Provisions must be made to protect the passengers and crew from injury by the contents of any compartment when the ultimate forward inertia force is 4 g.
[Revision note: Based on Sec. 7.356]
Sec. 29.365 Emergency evacuation.
(a) General. Each crew and passenger area must have means for rapid evacuation in a crash landing, with the landing gear extended and retracted, considering the possibility of fire. Passenger entrance, crew, and service doors may be considered as emergency exits if they meet the applicable requirements of this section.
(b) Flight crew emergency exits. For rotorcraft with passenger emergency exits that are not convenient to the flight crew, flight crew emergency exits must be provided in the crew area for rapid evacuation. These exits must be located--
(1) On both sides of the rotorcraft; or
(2) As top hatches.
(c) Passenger emergency exits; type and location. For the purpose of paragraphs (d), (f), and (i) of this section, the types of exits are as follows:
(1) Type I. This type must have a rectangular opening at least 24 inches wide by 48 inches high, with corner radii not greater than four inches, located in the passenger area in the side of the fuselage at floor level and as far away as practicable from areas that might become potential fire hazards in a crash.
(2) Type II. This type is the same as Type I, except that the opening must be at least 20 inches wide by 44 inches high.
(3) Type III. This type is the same as Type I, except that---
(i) The opening must be at least 20 inches wide by 36 inches high; and
(ii) The exits need not be at floor level.
(4) Type IV. This type must have a rectangular opening at least 19 inches wide by 26 inches high, with corner radii not greater than four inches, located in the side of the fuselage with a step-up inside the rotorcraft of not more than 29-inches.
(d) Passenger emergency exits; side-of-fuselage. Emergency exits must be accessible to the passengers and must be provided in accordance with the following table:
Passenger seating
capacity | Emergency exits | for each side of | the fuselage |  |
| Type
I | Type
II | Type
III | Type
IV |
1 through 19--------- | ---------- | ----------- | 1 | --------- |
20 through 39------- | ---------- | 1 | ------------ | 1 |
40 through 60------- | 1 | ----------- | ------------ | 1 |
(e) Passenger emergency exits; other than side-of-fuselage. In addition to the requirements of paragraph (d) of this section, it must be shown that-----
(1) Enough openings are provided in the top, bottom, or ends of the fuselage to allow evacuation with the rotorcraft on its side; or
(2) The probability of the rotorcraft coming to rest on its side in a crash landing is extremely remote.
(f) Emergency exit arrangement. Emergency exits must be arranged as follows:
(1) Each emergency exit must consist of a movable door or hatch in the external walls of the fuselage and must provide an unobstructed opening to the outside.
(2) Each emergency exit must be openable from the inside and from the outside.
(3) The means of opening each emergency exit must be simple and obvious and may not require exceptional effort.
(4) Means must be provided for locking each emergency exit and for preventing opening in flight inadvertently or as a result of mechanical failure.
(5) Provision must be made to minimize the probability of the jamming of any emergency exit in a minor crash landing as a result of fuselage deformation.
(6) For each emergency exit (other than Type IV exits located above a wing) that is more than six feet from the ground with the rotorcraft on the ground and the landing gear extended, means must be provided to assist the occupants to the ground.
(g) Emergency exit functioning. The proper functioning of each emergency exit must be shown by test.
(h) Emergency exit marking. Each emergency exit, its means of access, and its means of opening must be conspicuously marked. In addition---
(1) The identity and location of each emergency exit must be recognizable from a distance equal to the width of the cabin;
(2) The location of each emergency exit operating handle and the instructions for opening must be marked on or adjacent to the emergency exit, and this marking must be readable from a distance of 30 inches:
(3) Source of light, independent of the main lighting system, must be installed to illuminate all emergency exit markings;
(4) Each exit light must be designed to function automatically in a crash landing and to operate manually; and
(5) Each emergency exit and its means of opening must be marked on the outside of the rotorcraft.
(i) Emergency exit access. Access to emergency exits must be provided as follows:
(1) Each passageway between passenger compartments, and each passageway leading to Type I and Type II emergency exits, must be unobstructed and at least 20 inches wide.
(2) For each emergency exit covered by paragraph (f) (6) of this section, there must be enough space adjacent to that exit to allow a crewmember to assist in the evacuation of passageway below that required for that exit.
(i) Width of main aisle. The main passenger aisle width between seats must equal or exceed the values in the following table:
| Minimum main passenger | aisle width |
| Passenger seating capacity | Less than 25 inches from floor | 25 inches and more from floor |
| inches | inches |
| 10 or less ------------------ | 12 | 18 |
| 11 through 19 ------------------ | 12 | 20 |
| 20 or more ------------------ | 15 | 20 |
[Revision note: Based on Sec. 7.357]
Sec. 29.367 Ventilation.
(a) Each passenger and crew compartment must be ventilated, and each crew compartment must have enough fresh air (but not less than 10 cu. ft. per minute per crew member) to enable crewmembers to perform their duties without undue discomfort or fatigue.
(b) All crew and passenger compartment air must be free from harmful or hazardous concentrations of gases or vapors.
(c) The concentration of carbon monoxide may not exceed one part in 20,000 parts of air during forward flight. If the concentration exceeds this value under other conditions, suitable operating restrictions must be provided.
(d) Provisions must be made to ensure compliance with paragraphs (b) and (c) of this section under any reasonably probable failure of any ventilation, heating or other system or equipment.
[Revision note: Based on Sec. 7.358 (less note following (c))]
Sec. 29.369 Heaters.
Each combustion heater must be approved.
[Revision note: Based on Sec. 7.359]
FIRE PREVENTION
Sec. 29.377 General.
(a) Hand fire extinguishers. For hand fire extinguishers the following rules apply:
(1) Each hand fire extinguisher must be approved.
(2) The types and quantities of each extinguishing agent used must be appropriate to the kinds of fires likely to occur where used.
(3) Each extinguisher for use in a personnel compartment must be designed to minimize the hazard of toxic gas concentrations.
(b) Built-in fire extinguishers. If a built-in fire extinguishing system is required--
(1) The capacity of each system, in relation to the volume of the compartment where used and the ventilation rate, must be adequate for any fire likely to occur in that compartment.
(2) Each system must be installed so that--
(i) No extinguishing agent likely to enter personnel compartments will be hazardous to the occupants; and
(ii) No discharge of the extinguisher can cause structural damage.
[Revision note: Based on Sec. 7.360]
Sec. 29.379 Cabin interiors.
For each compartment used by the crew or passengers---
(a) All materials must be at least flash-resistant;
(b) All wall and ceiling linings, and the covering of all upholstery, floors, and furnishings must be at least flame resistant;
(c) Each compartment where smoking is to be allowed must leave self-contained, removable, ash trays, and all other compartments must be placarded against smoking;
(d) Each receptacle for towels, paper, or waste must be at least fire-resistant and must have means for containing possible fires;
(e) A hand fire extinguisher must be provided for the flight crewmembers; and
(f) At least the following number of hand fire extinguishers must be conveniently located in passenger compartments:
| Passenger capacity: | Minimum number of hand fire extinguishers |
| 7 through 30......................................... | 1 |
| 31 through 60....................................... | 2 |
[Revision note: Based on Sec. 7.381]
Sec. 29.381 Cargo and baggage compartments.
(a) Each cargo and baggage compartment must be constructed of, or lined with materials that are at least fire resistant.
(b) No compartment may contain any controls, wiring, lines, equipment, or accessories whose damage or failure would affect safe operation, unless those items are protected so that-------
(1) They cannot be damaged by the movement of cargo in the compartment; and
(2) Their breakage of failure will not create a fire hazard.
(c) The design and sealing of inaccessible compartments must be adequate to contain compartment fires until a landing and safe evacuation can be made.
(d) Each cargo and baggage compartment must have a device to ensure detection of fires by a crewmember at his station, and to prevent the entry of harmful quantities of smoke, flame, extinguishing agents, and other noxious gases into any crew or passenger compartment. This must be shown in flight.
(e) For each compartment that is to be accessible in flight, protective breathing equipment must be available for the appropriate crewmember.
[Revision note: Based on Sec. 7.382 (less note following (a))]
Sec. 29.383 Combustion heater fire protection.
(a) Combustion heater fire zones. The following combustion heater fire zones must be protected against fire under the applicable provisions of Secs. 29.631 through 29.643, and 29.647:
(1) The region surrounding any heater, if that region contains any flammable fluid system components (including the heater fuel system), that could ---
(i) Be damaged by heater malfunctioning; or
(ii) Allow flammable fluids or vapors to reach the heater in case of leakage.
(2) Each portion of any ventilating air passage that---
(i) Surrounds the combustion chamber; and
(ii) Would not contain (without damage to other rotorcraft components) any fire that may occur within the passage.
(b) Ventilating air ducts. Each ventilating air ducts passing through any fire zone must be fireproof. In addition---
(1) Unless isolation is provided by fireproof valves or by equally effective means, the ventilation air duct downstream of each heater must be fireproof for a distance great enough to ensure that any fire originating in the heater can be contained in the duct; and
(2) Each portion of any ventilating duct passing through any region having a flammable fluid system must be so constructed or isolated from that system that the malfunctioning of any component of that system cannot introduce flammable fluids or vapors into the ventilating airstream.
(c) Combustion air ducts. Each combustion air duct must be fireproof for a distance great enough to prevent damage from backfiring or reverse flame propagation. In addition-----
(1) No combustion air duct may communicate with the ventilating airstream under any operating condition, including reverse flow of malfunctioning of the heater or its associated components and
(2) No combustion air duct may restrict the prompt relief of any backfire that, if so restricted, could cause heater failure.
(d) Heater controls: general. Provision must be made to prevent the hazardous accumulation of water or ice on or in any heater control component, control system tubing, or safety control.
(e) Heater safety controls. For each combustion heater, safety control means must be provided as follows:
(1) Means independent of the components provided for the normal continuous control of air temperature, airflow, and fuel flow, must be provided for each heater to automatically shut off the ignition and fuel supply to that heater at a point remote from that heater, when----
(i) The heat exchanger temperature or ventilation air temperature exceeds safe limits; or
(ii) Either the combustion airflow becomes inadequate for safe operation.
(2) The means of complying with subparagraph (1) of this paragraph for any individual heater must---
(i) Be independent of all components serving any other heater whose heat output is essential for safe operation; and
(ii) Ensure that the heater will remain off until restarted by the crew.
(3) Means must be provided to warn the crew when any heater whose heat output is essential for safe operation has been shut off by the automatic means prescribed in subparagraph (1) of this paragraph.
(f) Air intakes. Each combustion and ventilation air intake must be so located that no flammable fluids or vapors can enter the heater system under any operating condition---
(1) During normal operation; or
(2) As a result of the malfunctioning of any other component.
(g) Heater exhaust. Each heater exhaust system must conform with Sec. 29.585 (a) and (b). In addition---
(1) Each exhaust shroud must be sealed so that no flammable fluids or hazardous quantities of vapors can reach the exhaust systems through joints; and
(2) No exhaust system may restrict the prompt relief of any backfire that, if so restricted, could cause heater failure.
(h) Heater fuel systems. Each heater fuel system must conform with all powerplant fuel system requirements affecting safe heater operation. Each heater fuel system component within the ventilating airstream must be protected by shrouds so that no leakage from those components can enter the ventilating airstream.
(i) Drains. Means must be provided for safe drainage of fuel that might accumulate within the combustion chamber or the heat exchanger. In addition---
(1) Each portion of any drain that operates at high temperatures must be protected in the same manner as heater exhausts; and
(2) Each drain must be protected against hazardous ice accumulation under all operating conditions.
[Revision note: Based on Sec. 7.383]
Sec. 29.385 Fire protection of structure, controls, and other parts.
All parts of the structure, controls, and the rotor mechanism, and other parts essential to controlled flight and landing that would be affected by powerplant fires must be isolated under Sec. 29.643, or must be--
(a) For category A rotorcraft, fireproof; and
(b) For category B rotorcraft, protected so that they can perform their essential functions for at least five minutes under all foreseeable powerplant fire conditions.
[Revision note: Based on Sec. 7.384]
Sec. 29.387 Flammable fluid fire protection.
If flammable fluids or vapors might be liberated by the leakage of fluid systems, means must be provided to---
(a) Prevent the ignition of those fluids or vapors by any other equipment; or
(b) Control any fire resulting from that ignition.
[Revision note: Based on Sec. 7.385]
MISCELLANEOUS
Sec. 29.395 Leveling marks.
Reference marks must be provided for use in leveling the rotorcraft on the ground.
[Revision note: Based on Sec. 7.390]
Sec. 29.397 Ballast provisions.
All ballast provisions must be so designed and constructed as to prevent the inadvertent shifting of ballast in flight.
[Revision note: Based on Sec. 7.391]
Sec. 29.399 Ice protection.
The rotorcraft must be able to operate safely throughout the range of icing conditions for which certification is requested.
[Revision note: Based on Sec. 7.392]
Subpart E-Powerplant Installation
GENERAL
Sec. 29.421 General.
(a) For the purpose of this part, the rotorcraft powerplant installation includes all parts of the rotorcraft (other than the main and auxiliary rotor structures) that--
(1) Are necessary for propulsion:
(2) Affect the control of the major propulsive units; or
(3) Affect the safety of the major propulsive unites between normal inspection or overhauls.
(b) For each powerplant installation--
(1) The installation must conform with all applicable provisions of this subpart and, for turbine powerplant installations, with all other requirements necessary for safety;
(2) All components of the installation must be constructed, arranged and installed to ensure their continued safe operation between normal inspections or overhauls;
(3) Accessibility must be provided to allow any inspection and maintenance necessary to ensure continued airworthiness; and
(4) Electrical interconnections must be provided to prevent differences of potential between major components of the installation and the rest of the rotorcraft.
[Revision note: Based on Sec. 7.400]
Sec. 29.423 Engines.
(a) Engine type certification. Each engine must be typed certificated under Part 33 [New].
(b) Category A; engine isolation. For each category A rotorcraft, the powerplants must be arranged and isolated form each other to allow operation , in at least one configuration so that the failure or malfunctioning of any engine, or the failure of any system that can affect any engine, will not--
(1) Prevent the continued safe operation of the remaining engines; or
(2) Require immediate action by crewmembers for continued safe operation.
(c) Category A; control of engine rotation. For each category A rotorcraft, means must be provided for stopping and restarting any engine individually in fight. In addition---
(1) All components for controlling engine rotation in flight that are on the engine side of the firewall and that might be exposed to fire must be at least fire-resistant; or
(2) Duplicate means must be available for this purpose and their controls must be so located that all are not likely to be damaged at the same time in case of fire.
(d) Category A: engine cooling fan blade protection. If an engine cooling fan is installed in a category A rotorcraft, means must be provided to ensure that a fan blade failure will not affect the operation of the remaining engines or prevent continued safe operation.
(e) Category B; engine cooling fan blade protection. If an engine cooling fan is installed, means must be provided to protect the rotorcraft and to allow a safe landing if a fan blade fails. This must be shown by showing that---
(1) All fan blades are contained in the event of failure;
(2) Each fan is so located that a failure will not jeopardized the safety of the rotorcraft or its occupants; or
(3) Each fan blade is able to withstand an ultimate load of 1.5 time the centrifugal force resulting from engine r.p.m. limited by either---
(i) The terminal engine r.p.m. under uncontrolled conditions; or
(ii) An overspeed limiting device.
[Revision note: Based on Sec. 7.401]
Sec. 29.425 Engine vibration.
(a) Each engine must be installed to prevent the harmful vibration of any engine or rotorcraft part.
(b) The addition of the rotor and the rotor drive system to the engine may not subject the principal rotating portions of the engine to excessive vibration. This must be shown by means of a vibration investigation.
[Revision note: Based on Sec. 7.402]
ROTOR DRIVE SYSTEM
Sec. 29.435 Rotor drive system.
(a) General. The rotor drive system includes al parts necessary to transmit power from the engines to the rotor hubs. This includes gear boxes, shafting, universal joints, couplings, rotor brake assemblies, clutches, supporting bearings for shafting, all attendant accessory pads or drives, and all cooling fans that are not included in the certification of the engine.
(b) Arrangement. Rotor drive systems must be arranged as follows:
(1) Each rotor drive system of multiengine rotorcraft must be so arranged that each rotor necessary for operation and control will continue to be driven by the remaining engines if any engine fails.
(2) For single-engine rotorcraft, each rotor drive system must be so arranged that all rotors necessary for control in autorotation will continue to be driven by the main rotors after disengagement of the engine from the main and auxiliary rotors.
(3) Each rotor drive system must incorporate a unit for each engine that will automatically disengage that engine from the main and auxiliary rotors if that engine fails.
(4) If a torque limiting device is used in the rotor drive system, it must be located to allow continued control of the rotorcraft when it is operating.
(5) If the rotors must be phased for intermeshing, each system must provide constant and positive phase relationship under all operating conditions.
(6) If a rotor dephasing device is incorporated, means must be provided to ensure that the rotors are locked in proper phase prior to operation.
[Revision note: Based on Sec. 7.408]
Sec. 29.437 Rotor brake.
If a means is provided to control the rotation of the rotor drive system independent of the engine, all limitations on the use of that means must be specified, and the control for that means must be guarded to prevent inadvertent operation.
[Revision note: Based on Sec. 7.404]
Sec. 29.439 Rotor drive system and control mechanism test.
(a) Endurance tests: general. Each rotor drive system and rotor control mechanism must be tested for not less than 200 hours. These tests must be conducted--
(1) On the rotorcraft, with the power being absorbed by the actual rotors to be installed; and
(2) In compliance with paragraphs (b) through (j) of this section in 10 hour test cycles.
(b) Endurance tests; takeoff power run. The takeoff power endurance test run must consist of one hour of alternate runs of five minutes at takeoff power and speed, and five minutes at as low an engine idle speed as practicable. The engine must be declutched from the rotor drive system, and the rotor brake, if furnished and so intended, must be applied during the first minute of the idle run. During the remaining four minutes of the idle run, the clutch must be engaged so that the engine drives the rotors at the minimum practical r.p.m. Acceleration of the engine and the rotor drive system must be accomplished at the maximum rate. When declutching the engine, it must be decelerated at a rate sufficiently rapid to allow the operation of the overrunning clutch. In the absence of a takeoff rating, maximum continuous power and speed must be substituted for takeoff power and speed.
(c) Endurance tests: maximum continuous run. Three hours of continuous operation at maximum continuous power and speed must be conducted as follows:
(1) The main rotor controls must be operated at a minimum of 15 times each hour through the main rotor pitch positions of full vertical thrust, maximum forward thrust component, maximum aft thrust component, maximum left thrust component, and maximum right thrust component, except that the control movements need not produce loads or blade flapping motion exceeding the maximum loads or motions encountered in flight.
(2) The directional controls must be operated at a minimum of 15 times each hour through the control extremes of maximum right turning torque, neutral torque as required by the power applied to the main rotor, and maximum left turning torque.
(3) Each maximum control position must be held for a t least 10 seconds, and the rate of change of control position must be at least as rapid as that for normal operation.
(d) Endurance tests: 90 percent of maximum continuous run. One hour of continuous operation must be conducted at 90 percent of maximum continuous power and speed.
(e) Endurance tests: 80 percent of maximum continuous run. One hour of continuous operation must be conducted at 80 percent of maximum continuous power and speed.
(f) Endurance tests: 60 percent of maximum continuous run. Two hours of continuous operation at 60 percent of maximum continuous power must be conducted at minimum desired cruising speed or at 90 percent of maximum continuous speed, whichever is less.
(g) Endurance tests: engine malfunctioning run. It must be determined whether malfunctioning of such components as the engine fuel or ignition systems, or whether unequal engine power can result in dynamic conditions detrimental to the drive system. If so, a suitable number of hours of operation must be accomplished under those conditions, one hour of which must be included in each cycle, and the remaining hours of which must be accomplished at the end of the 20 cycles. If no detrimental condition results, an additional hour of operation in compliance with paragraph
(b) of this section must be conducted.
(h) Endurance tests: overspeed run. One hour of continuous operation at 110 percent of maximum continuous speed must be conducted at maximum continuous speed must be conducted at maximum continuous power. If the engines are limited by the manufacture to an overspeed of less than 110 percent of maximum continuous speed for the highest speed allowable for those engines.
(1) Endurance tests: rotor control positions. When the rotor controls are not being cycled during the tie-down tests, the rotor must be operated, using the procedures prescribed in paragraph (c) of this section, to produce each of the minimum thrust positions for the following percentages of test time (except that the control positions need not produce loads or blade flapping motion exceeding the maximum loads or motions encountered in flight):
(1) For full vertical thrust, 20 percent,
(2) For the forward thrust component, 50 percent.
(3) For the right thrust component, 10 percent.
(4) For the left thrust component, 10 percent.
(5) For the aft thrust component, 10 percent.
(j) Endurance tests: clutch and brake engagements. A total of at least 400 clutch and brake engagements, including the engagements of paragraph (b) of this section, must be made during the takeoff power runs and, if necessary, at each change of power and speed throughout the test. In each clutch engagement, the shaft on the driven side of the clutch must be accelerated from rest. The clutch engagements must be accomplished at the speed and by the method prescribed by the applicant. During deceleration after each clutch engagement, the engines must be stopped rapidly enough to allow the engines to be automatically disengaged from all rotors and rotor drives. If a rotor brake is installed for stopping the rotor, the clutch, during brake engagements, must be disengaged above 40 percent of maximum continuous rotor speed and the rotors allowed to decelerate to 40 percent of maximum continuous rotor speed at which time the rotor brake must be applied. If the clutch design does not allow stopping the rotors with the engine running, or if no clutch is provided, the engine must be stopped before each application of the rotor brake, and then application of the rotor brake, and then immediately restarted after the rotors stop.
(k) Overspeed test. After completion of the 200-hour tie-down test, and without intervening major disassembly, the rotor drive system must be subjected to 50 overspeed runs, each 30±3 seconds in duration at 120 percent of maximum continuous speed. These runs must be conducted as follows:
(1) Overspeed runs must be alternated with stabilizing runs of from one to five minutes duration each at 60 to 80 percent of maximum continuous speed.
(2) Acceleration and deceleration must be accomplished in a period not longer than 10 seconds, and the time for changing speeds may not be deducted from the specified time for the overspeed runs.
(3) Overspeed runs must be made with the rotors in the flattest pitch for smooth operation.
(4) If the engines are limited by the engine manufacturer to an overspeed of less than 120 percent of maximum continuous speed for the periods required, the speed used must be the highest speed allowable for the engines involved.
(1) All components that are affected by maneuvering and gust loads must be investigated for the same flight conditions as are the main rotors, and their service lives must be determined by fatigue tests or by other approved methods. In addition, a level of safety equal to that of the main rotors must be provided for---
(1) All components in the rotor drive system whose failure would cause an uncontrolled landing:
(2) All components essential to the phasing of rotor on multirotor rotorcraft, or which furnish a driving link for the essential control of rotors in autorotation; and
(3) All components common to two or more engines on multiengine rotorcraft.
(m) Special teats. Each rotor drive system designed to operate at two or more gear ratios must be subjected to special testing for durations found necessary to substantiate the safety of the rotor drive system.
[Revision note: Based on Sec. 7.405 (less sentences (4) and (5) of (a) (1))]
Sec. 29.441 Additional tests.
All additional dynamic, endurance, and operational tests, and all vibratory investigations necessary to determine that the rotor drive mechanism is safe, must be performed.
[Revision note: Based on Sec. 7.406
Sec. 29.443 Shafting critical speed.
(a) An investigation must be made to determine whether the critical speeds of all shafting lie outside the range of allowable engine speeds under idling, power on, and autorotative conditions.
(b) All critical vibration existing from (and including) clutch engagement to maximum overspeed, during acceleration or deceleration, must be within safe limits.
(c) If the demonstration required by paragraph (b) of this section is made during the endurance testing, the test schedule may substitute the critical vibration conditions for equivalent time in appropriate portions of the endurance test procedure.
[Revision note: Based on Sec. 7.407]
Sec. 29.445 Shafting joints.
All universal joints, slip joints, and other shafting joints whose lubrication is necessary for operation must have provision for lubrication.
[Revision note: Based on Sec. 7.408]
FUEL SYSTEM
Sec. 29.453 General.
(a) Each fuel system must be constructed and arranged to ensure a flow of fuel at a rate and pressure established for proper engine functioning under all likely operating conditions, including all maneuvers for which certification is requested.
(b) Each fuel system must be arranged so that---
(1) No engine or fuel pump can draw fuel from more than one tank at a time; or
(2) Means are provided to prevent in introducing air into the system.
[Revision note: Based on Sec. 7.410]
Sec. 29.455 Fuel system independence.
(a) For category A rotorcraft---
(1) The fuel system must conform to the requirements of Sec. 29.423(b); and
(2) Unless other provisions are made in compliance with subparagraph (1) of this paragraph, the fuel system must allow fuel to be supplied to each engine through a system independent of all portions of each system supplying fuel to other engines.
(b) Each fuel system for multiengine category B rotorcraft must conform to paragraph (a) (2) of this section. However, separate fuel tanks need not be provided for each engine.
[Revision note: Based on Sec. 7.411]
Sec. 29.457 Fuel flow.
(a) Each fuel system must provide not less than 100 percent of the fuel flow required under all intended operating conditions and maneuvers. Compliance must be shown as follows:
(1) Fuel must be delivered to each engine at a pressure within the limits specified in the engine type certificate.
(2) The quantity of fuel in the tank being considered may not exceed the sum of the amount established as the unusable fuel supply for that tank under the provisions of Sec. 29.459 and that necessary for showing compliance with this section.
(3) All main pumps must be used that are necessary for each operating condition and attitude for which compliance with this section is shown, and the appropriate emergency pump must be substituted for each main pump so used.
(4) If a fuel flowmeter is provided, operation of the meter must be blocked in determining compliance with this section, and the fuel must flow through the meter or its bypass.
(b) If an engine can feed from more than one fuel tank, the fuel system must feed promptly when the fuel supply becomes low in one tank and another tank is selected.
[Revision note: Based on Sec. 7.413]
Sec. 29.459 Unusable fuel supply.
The unusable fuel supply for each tank must be selected by the applicant and established as not less than that quantity at which the first evidence of malfunctioning occurs under the most adverse fuel feed condition occurring under all intended operations and flight maneuvers involving that tank.
[Revision note: Based on Sec. 7.416]
Sec. 29.461 Fuel system hot weather operation.
(a) For each rotorcraft--
(1) The fuel system must be arranged to minimize the probability of vapor formation in the system under all normal operating conditions; and
(2) Each rotorcraft with suction lift fuel systems or systems likely to produce vapor must be free from vapor lock when using fuel at a temperature of at least 110 degrees F. under critical operating conditions.
(b) For each category A rotorcraft, satisfactory hot weather operation must be shown by showing that there is no evidence of vapor lock or other malfunctioning when the rotor craft is climbed from the altitude of the airport selected by the applicant to an altitude of 5,000 feet above the airport elevation, or to the maximum altitude at which the rotorcraft is expected to operate, whichever is greater.
(c) Compliance with paragraph (b) of this section must be shown in flight or on the ground under conditions closely stimulation flight conditions, and with---
(1) All engines at takeoff power at the beginning of the test and for the maximum time approved for takeoff power, and at maximum continuous power thereafter;
(2) The weight including full fuel tanks, minimum crew, and only that ballast necessary to maintain the center of gravity within allowable limits;
(3) The speed for best rate of climb under the test conditions; and
(4) Fuel at a temperature of at least 110 degrees F. at the beginning of the demonstration.
(d) If compliance with paragraph (b) of this section is shown in weather cold enough to interfere with the proper conduct of the test, each fuel tank surface, fuel line, and other fuel system part subject to cold air must be insulated to simulate, insofar as practicable, flight in hot weather.
[Revision note: Based on Sec. 7.417]
Sec. 29.463 Flow between interconnected tanks.
(a) Where tank outlets are interconnected and allow flow between them due to gravity or flight accelerations, it must be impossible for fuel to flow between tanks in quantities great enough to cause fuel to overflow from the tank vent in any sustained flight condition.
(b) If fuel can be pumped from one tank to another in flight--
(1) The design of the vents and the fuel transfer system must prevent structural damage to tanks from overfilling; and
(2) Means must be provided to warn the crew before overflow through the vents occurs.
[Revision note: Based on Sec. 7.413]
FUEL TANK CONSTRUCTION AND INSTALLATION
Sec. 29.473 General.
(a) Each fuel tank must be able to withstand, without failure, all vibration, inertia, fluid, and structural loads to which it may be subjected in operation.
(b) Each fuel tank and its installation must be designed or protected to retain fuel without leakage under the emergency landing conditions in Sec. 29.229.
(c) Each flexible fuel tank liner must be approved.
(d) Each fuel tank and its installation must be approved.
(d) Each integral fuel tank must have facilities for inspection and repair of its interior.
[Revision note: Based on Sec. 7.420]
Sec. 29.475 Fuel tank tests.
(a) Each fuel tank must be able to withstand the applicable pressure tests in this section without failure or leakage. If practicable, test pressures may be applied in a manner simulating the actual pressure distribution in service.
(b) Each conventional mental tank, each nonmetallic tank with walls that are not supported by the rotorcraft structure, and each integral tank must be subjected to a pressure of 3.5 p.s.i. unless the pressure developed during the maximum limit acceleration or emergency deceleration with a full tank exceeds this value, in which case a hydrostatic head, or equivalent test, must be applied to duplicate the acceleration loads so far as possible. However the pressure need not exceed 3.5 p.s.i. on surfaces not exposed to the acceleration loading .
(c) Each nonmetallic tank with walls supported by the rotorcraft structure must be subjected to the following tests:
(1) A pressure test of at least 2.0 p.s.i. This test may be conducted on the tank alone in conjunction with the test specified in subparagraph (2) of this paragraph.
(2) A pressure test, with the tank mounted in the rotorcraft structure, equal to the load developed by the reaction of the contents, with the tank full, during the maximum limit acceleration or emergency deceleration of the rotorcraft. However, the pressure need not exceed 2.0 p.s.i. on surfaces not exposed to the acceleration loading
(d) Each tank with large unsupported or unstiffened flat areas, or with other features whose failure or deformation could cause leakage, must be subjected to the following test, or its equivalent:
(1) The complete tank assembly together with its supports must be subjected to a vibration test when mounted in a manner simulating the actual installation.
(2) The tank assembly must be vibrated for 25 hours while two-thirds full of any suitable fluid. The amplitude of vibration may not be less than one thirty-second of an inch, unless otherwise substantiated.
(3) The frequency of vibration must be 90 percent of the maximum continuous rated speed of the engine, unless some other frequency within the normal speed range of the engine or rotor system is more critical, in which case the latter speed must be used and the time of test must be adjusted to accomplish the same number of vibration cycles.
(4) During the test, the tank assembly must be rocked at the rate of 16 to 20 complete cycles per minute through an angle of 15 degrees on either side of the horizontal (30 degrees total), about the most critical axis, for 25 hours. If motion about more than one axis is likely to be critical, the tank must be rocked about each axis for 12½ hours.
[Revision note: Based on Sec. 7.421]
Sec. 29.477 Fuel tank installation.
(a) The method of support for fuel tanks must prevent harmful load concentrations, on unsupported tank surfaces, resulting form the weight of the fuel in the tank,. In addition;
(1) Pads must be provided, if necessary, to prevent chafing between each tank and its supports.
(2) All padding must be nonabsorbent.
(3) If flexible tank liners are used they must be supported so that they are not required to withstand fluid loads.
(4) Each interior surface of tank compartments must be smooth and free of projections which could cause wear of the liner, unless---
(i) Provisions are made for protection of the liner at those points; or
(ii) The construction of the liner itself provides such protection.
(b) All spaces adjacent to tank surfaces must be adequately ventilated to avoid accumulation of fuel or fumes in these spaces due to minor leakage. If tank is in a sealed compartment, ventilation may be limited to drain holes that prevent clogging and that prevent excessive pressure resulting from altitude changes. If flexible tank liners are installed, the venting arrangement for the spaces between the liner and its container must maintain the proper relationship to tank vent pressures for all expected flight conditions.
(c) The location of each tank must conform with Sec. 29.633 (b) and (c).
(d) No portion of rotorcraft skin immediately adjacent to a major air outlet from the engine compartment may act as the wall of an integral tank.
(e) Each fuel tank must be isolated from personnel compartments by a fumeproof and fuelproof enclosure.
(f) Each fuel tank close to personnel compartments, engines, or combustion heaters must be designed, or protected and installed, to retain its contents under the loads specified in Sec. 29.229.
[Revision note: Based on Sec. 7.422]
Sec. 29.479 Fuel tank expansion space.
Each fuel tank must have an expansion space of not less than two percent of the tank capacity. It must be impossible to fill the expansion space inadvertently with the rotorcraft in the normal ground attitude.
[Revision note: Based on Sec. 7.423]
Sec. 29.481 Fuel tank sump.
(a) Each fuel tank must have a sump with a capacity of not less than the greater of--
(1) 0.10 percent of the tank capacity; or
(2) 1/16 gallon.
(b) The capacity prescribed in paragraph (a) of this section must be effective with the rotorcraft in all normal attitudes, and must be located so that the sump contents cannot escape through the tank outlet opening.
(c) Each fuel tank must allow drainage of all hazardous quantities of water from all portions of the tank to its sump with the rotorcraft in the ground attitude.
(d) Each fuel tank sump must have an accessible and easily operable drain that---
(1) Allows complete drainage of the sump on the ground;
(2) Discharges clear of all parts of the rotorcraft; and
(3) Has manual or automatic means for positive locking in the closed position.
[Revision note: Based on Sec. 7.424]
Sec. 29.483 Fuel tank filler connection.
(a) Each fuel tank filer connection must prevent the entrance of fuel into any portion of the rotorcraft other than the tank itself. In addition---
(1) Each filler must be marked as prescribed in Sec. 29.863(c)(1);
(2) Each recessed filler connection that can retain any appreciable quantity of fuel must have a drain that discharges clear of all parts of the rotorcraft; and
(3) Each filler cap must provide a fuel-tight seal under the pressure expected in normal operation.
(b) For category A rotorcraft, each filler cap or filler cap cover must provide a warning when the cap is not fully locked or seated on the filler connection.
[Revision note: Based on Sec. 7.425]
Sec. 29.485 Fuel tank vents and carburetor vapor vents.
(a) Fuel tank vents. Each fuel tank must be vented from the top of the expansion space so that venting is effective under all normal flight conditions. In addition---
(1) All vents must be arranged to avoid stoppage by dirt or ice formation;
(2) The vent arrangement must prevent the siphoning of fuel during normal operation;
(3) The venting capacity and vent pressure levels must maintain acceptable differences of pressure between the interior and exterior of the tank, during--
(i) Normal flight operation;
(ii) Maximum rate of ascent and descent; and
(iii) Refueling and defueling (where applicable);
(4) All airspaces of tanks with interconnected outlets must be interconnected:
(5) There may be no point in any vent line where moisture can accumulate with the rotorcraft in either the ground or the level flight attitude, unless drainage is provided; and
(6) No vent or drainage provision may terminate at any point---
(i) Where the discharge of fuel from the vent outlet would constitute a fire hazard; or
(ii) From which fumes could enter personnel compartments.
(b) Carburetor vapor vents. Each carburetor with vapor elimination connections must have a vent line to lead vapors back to one of the fuel tanks. In addition---
(1) Each vent system must have means to avoid stoppage by ice; and
(2) If more than one fuel tank is provided and it is necessary to use the tanks in a definite sequence, each vapor vent return line must lead back to the fuel tank used for takeoff and landing.
[Revision note: Based on Sec. 7.426]
Sec. 29.487 Fuel tank outlet.
A fuel strainer of 8 to 16 meshes per inch must be provided either for the fuel tank outlet or for the booster pump. In addition---
(a) The clear area of each fuel tank outlet strainer must be at least five times the area of the outlet line;
(b) The diameter of each strainer must be at least that of the fuel tank outlet; and
(c) Each finger strainer must be accessible for inspection and cleaning.
[Revision note: Based on Sec. 7.427]
Sec. 29.489 Pressure refueling and fueling provisions below fuel level in the tank.
(a) Each fueling connection below the fuel level in each tank must have means to prevent the escape of hazardous quantities of fuel from that tank in case of malfunctioning of the fuel entry valve.
(b) For systems intended for pressure refueling, a means in addition to the normal means for limiting the tank content must be installed to prevent damage to the tank in case of failure of the normal means.
[Revision note: Based on Sec. 7.428]
Sec. 29.501 Fuel pumps.
(a) Main pumps. Each fuel pump required for proper engine operation, or required to meet the fuel system requirements of this subpart (other than those in paragraph (b) of this section), is a main pump. For each main pump, provision must be made to allow the bypass of all positive displacement fuel pumps other than fuel injection pumps approved, as part of the engine that is, other than pumps that supply the proper flow and pressure for fuel injection when the injection is not accomplished in a carburetor.
(b) Emergency pumps. Emergency pumps must be provided to feed all engines immediately after the failure of any one main pump (other than fuel injection pump approved at part of the engine).
[Revision note: Based on Sec. 7.430 (less 2d and 3d sentences of note following (a))]
Sec. 29.503 Fuel pump installation.
(a) Provision must be made to maintain the fuel pressure, at the inlet to the carburetor, within the range of limits established for proper engine operation.
(b) When necessary for the maintenance of the proper fuel pressure--
(1) A connection must be provided to transmit the carburetor air intake static pressure to the proper fuel pump relief valve connection; and
(2) The gauge balance lines must be independently connected to the carburetor inlet pressure to avoid erroneous fuel pressure readings.
(c) The installation of fuel pumps having seals or diaphragms that may leak must have provisions for draining leaking fuel. Each drain line must discharge where it will not create a fire hazard.
[Revision note: Based on Sec. 7.431]
Sec. 29.505 Fuel system lines and fittings.
(a) Each fuel line must be installed and supported to prevent excessive vibration and to withstand all loads due to fuel pressure and accelerated flight conditions.
(b) Each fuel line connected to components of the rotorcraft between which relative motion could exist must incorporate provisions for flexibility.
(c) Each flexible connection in fuel lines that may be under pressure or subjected to axial loading must use flexible hose assemblies.
(d) All flexible hose must be approved.
(e) No flexible hose which might be adversely affected by high temperatures may be used where excessive temperatures will exist during operation or after engine shutdown.
[Revision note: Based on Sec. 7.432]
Sec. 29.507 Valves.
In addition to the requirements of Sec. 29.635, each fuel valve must--
(a) Have positive stops or suitable index provisions in the "on" and "off" positions; and
(b) Be supported so that no loads resulting from their operation or from accelerated flight conditions are transmitted to the lines attached to the valve.
[Revision note: Based on Sec. 7.434]
Sec. 29.509 Fuel Strainer.
(a) A strainer incorporating a sediment trap and drain must be provided in the fuel system between the fuel tanks and the engine and must be installed in an accessible location.
(b) Each strainer must protect the fuel pumps, fuel controls, and the engine against any foreign matter that might be in the fuel
(c) Each screening or straining element must be easily cleanable.
(d) Each strainer must be mounted so that its weight is not supported by any connecting line or by the inlet or outlet connections of the strainer itself.
[Revision note: Based on Sec. 7.435]
Sec. 29.511 Drains.
(a) Drainage of the fuel system must be accomplished by fuel strainer drains and by the drains prescribed in Sec. 29.481.
(b) Each drain must discharge clear of all parts of the rotorcraft and must incorporate manual or automatic means for positive locking in the closed position.
[Revision note: Based on Sec. 7.436]
Sec. 29.513 Fuel quality indicator.
(a) Each fuel quantity indicator must be installed to indicate clearly to the flight crew the quantity of fuel in each tank in flight.
(b) When two or more tanks are closely interconnected by gravity feed system and vented, and when it is impossible to feed from each tank separately, at least one fuel quantity indicator must be installed.
[Revision note: Based on Sec. 7.437]
OIL SYSTEM
Sec. 29.523 General.
(a) Each engine must have an independent oil system that can supply that engine with an appropriate quantity of oil at a temperature not exceeding that safe for continuous operation.
(b) The oil system for components of the rotor drive system that require continuous lubrication must be sufficiently independent of the lubrication systems of the engines to ensure the ability to---
(1) Operate with any engine inoperative; and
(2) Autorotate safely.
(c) The usable oil capacity of each system may not be less than the product of the endurance of the rotorcraft under critical operating conditions and the maximum allowable oil consumption of the engine under the same conditions, plus a suitable margin to ensure adequate circulation and cooling. Instead of a rational analysis of endurance and consumption, a total usable oil capacity of one gallon for each 40 gallons of usable fuel may be used for reciprocating engine installations.
(d) Oil-fuel ratios, lower than those prescribed in paragraph (c) of this section may be used if they are substantiated by data on the oil consumption of the engine.
(e) The ability of the engine and rotor drive system oil cooling provisions to maintain the oil temperature at or below the maximum established value must be shown in accordance with the applicable requirements of Secs. 29.551 through 29.561.
[Revision note: Based on Sec. 7.440]
Sec. 29.525 Oil tank construction.
(a) Oil tank expansion space. Expansion space must be provided as follows:
(1) Each oil tank must have an expansion space of not less than the greater of---
(i) 10 percent of the tank capacity; or
(ii) 0.5 gallon.
(2) Each reserve oil tank not directly connected to any engine must have an expansion space of not less than two percent of the tank capacity.
(3) It must be impossible to fill the oil tank expansion space inadvertently with the rotorcraft in the normal ground attitude.
(b) Oil tank filler connection. Each recessed oil tank filler connection that can retain any appreciable quantity of oil must incorporate a drain that discharges clear of all portions of the rotorcraft. In addition----
(1) Each oil tank filler cap must provide an oil-tight seal under the pressure expected in operation;
(2) For category A rotorcraft, each oil tank filler cap or filler cap cover must incorporate features that provide a warning when caps are not fully locked or seated on the filler connection; and
(3) Each oil filer must be marked as prescribed in Sec. 29.863(c)(2).
(c) Oil tank vent. Oil tanks must be vented as follows:
(1) Each oil tank must be vented from the top of the expansion space so that venting is effective under all normal fight conditions.
(2) Each oil tank vent must be arranged so that condensation of water vapor that might freeze and obstruct the line cannot accumulate at any point.
(d) Oil tank outlet. Provision must be made to prevent entrance into the tank itself, or into the tank outlet, of any object that might obstruct the flow of oil through the system. No oil tank outlet may be enclosed by any screen or guard that would reduce the flow of oil below a safe value at any operating temperature.
(e) Flexible oil tank liners. Each flexible oil tank liner must be approved.
[Revision note: Based on Sec. 7.441]
Sec. 29.527 Oil tank tests.
Each oil tank must be designed and installed so that---
(a) It can withstand, without failure, all vibration, inertia, and fluid loads to which it may be subjected in operation; and
(b) It conforms to the provisions of Sec. 29.475, except that the test pressure specified in Sec. 29.475(b) must be five p.s.i.
[Revision note: Based on Sec. 7.442]
Sec. 29.529 Oil tank installation.
Each oil tank installation must conform to the provisions of Sec. 29.477. However, an engine oil tank may be in a designated fire zone if the tank and its supports are fireproof to the extent that damage by fire to any non-fireproof part will not cause leakage of oil.
[Revision note: Based on Sec. 7.443]
Sec. 29.531 Oil lines and fittings.
(a) General. Each oil line must conform to the requirements of Sec. 29.505.
(b) Lines and fittings in designated fire zones. Each oil line and fitting in a designated fire zone must conform to the provisions of Sec. 29.637.
(c) Breather lines. Breather lines must be arranged so that---
(1) Condensation of water vapor that might freeze and obstruct the line cannot accumulate at any point;
(2) All breathers discharge where they will not constitute a fire hazard if foaming occurs, and so that emitted oil will not impinge on the pilot's windshield; and
(3) The breather does not discharge into the engine air induction system.
[Revision note: Based on Sec. 7.444)
Sec. 29.533 Oil valves.
(a) Each oil shutoff must conform to the requirements of Sec. 29.635.
(b) The closing of oil shutoff means may not prevent autorotation.
(c) Each oil valve must have positive stops or suitable index provisions in the "on" and "off" positions and must be supported so that no loads resulting from its operation or from accelerated flight conditions are transmitted to the lines attached to the valve.
[Revision note: Based on Sec. 7.445]
Sec. 29.535 Oil radiators.
(a) Each oil radiator must be able to withstand all vibration, inertia, and oil pressure loads to which it would be subjected in operation.
(b) Each oil radiator air duct must be located, or so equipped that, in case of fire, and with the airflow as it would be with and without the engine operating, flames cannot impinge directly upon the radiator.
[Revision note: Based on Sec. 7.446]
Sec. 29.537 Oil filters.
Each filter or strainer in the powerplant installation must be constructed and installed so that oil will flow at the normal rate through the rest of the system with the filter or strainer element completely blocked.
[Revision note: Based on Sec. 7.447]
Sec. 29.539 Oil drains.
Accessible drains must be provided that---
(a) Allow safe drainage of the entire oil system; and
(b) Have manual or automatic means for positive locking in the closed position.
[Revision note: Based on Sec. 7.448]
COOLING SYSTEMS
Sec. 29.551 General.
(a) All powerplant cooling provisions must be able to maintain the temperatures of all powerplant components, engine fluids, and the carburetor intake air within safe values under all critical surface (ground or water) and flight operating conditions.
(b) Cooling provisions must be provided to maintain all fluids in any power transmission within safe values under all critical surface (ground or water) and flight operating conditions.
(c) Compliance with paragraphs (a) and (b) of this section must be shown by flight test in which the temperatures of flight tests in which the temperatures of selected powerplant component, engine, and transmission fluids are obtained under the conditions prescribed in paragraphs (a) and (b) of this section.
[Revision note: Combines Secs. 7.450 and 7.451 (1st sentence)]
Sec. 29.553 Cooling tests.
(a) General. For the tests prescribed in Sec. 29.551 (c), the following rules apply:
(1) If the tests are conducted under conditions deviating from the maximum anticipated air temperature specified in paragraph (b) of this section, all recorded powerplant temperature must be corrected under paragraphs (c) and (d) of this section, unless a more rational correction method is applicable.
(2) No corrected temperature determined under subparagraph (1) of this paragraph may exceed established limits.
(3) All fuel used during the cooling tests must be of the minimum grade approved for the engines, and all mixture settings must be those used in normal operation.
(4) The test procedures must be as prescribed in Secs. 29.555 through 29.561.
(b) Maximum anticipated air temperature. For cooling tests, the maximum anticipated temperature (hot-day condition) is 100 degrees F. at sea level, decreasing from this value at the rate of 3.6 degrees F. per thousand feet of altitude above sea level up to the altitude at which a temperature of -67 degrees F. is reached, above which altitude the temperature is constant at ---67 degrees F.
(c) Correction factor for cylinder head, oil inlet, carburetor air, and engine and transmission coolant outlet temperatures. The cylinder head, oil inlet, carburetor air, and engine coolant outlet temperatures must be corrected by adding to those temperatures the difference between the maximum anticipated air temperature and the temperature of the ambient air at the time of the first occurrence of the maximum head, oil, air, or coolant temperatures recorded during the cooling test.
(d) Correction factor for cylinder barrel temperatures. Cylinder barrel temperatures must be corrected by adding to those temperatures 0.7 times the difference between the maximum anticipated air temperatures and the temperature of the ambient air at the time of the first occurrence of the maximum cylinder barrel temperature recorded during the cooling test.
[Revision note: Based on Sec. 7.451]
Sec. 29.555 Climb cooling test procedures.
(a) Climb cooling tests must be conducted in accordance with this section for--
(1) All category A rotorcraft; and
(2) All multiengine category B rotorcraft for which certification is desired under the category A powerplant installation requirements, and under the requirements of Sec. 29.385 (a) at the steady rate of climb or descent established under Sec. 29.53 (c).
(b) The climb or descent cooling test must be conducted with the engine in operative that produces the most adverse cooling conditions for the remaining engines and powerplant components.
(c) Each operating engine must be at maximum continuous power of at full throttle when above the critical altitude.
(d) After temperatures have stabilized in flight, the climb must be--
(1) Begun from an altitude not greater than the lower of--
(i) 1,000 feet below the engine critical altitude; and
(ii) 1,000 feet below the maximum altitude at which the rate of climb is 150 f.p.m.; and
(2) Continued for at least five minutes after the occurrence of the highest temperature recorded, or until the rotorcraft reaches the maximum altitude for which certification is request.
(e) For category B rotorcraft without a positive rate of climb, the descent must begin at the all-engine-critical altitude and end at the higher of---
(1) The maximum altitude at which level flight can be maintained with one engine operative; and
(2) Sea level.
(f) The climb or descent must be conducted at an airspeed representing a normal operational practice for the configuration being tested. However, if the cooling provisions are sensitive to rotorcraft speed, the most critical airspeed must be used, but need not exceed the speeds established in accordance with Secs. 29.51(b) or 29.53(c). The climb cooling test may be conducted in conjunction with the takeoff cooling test of Sec. 29.557.
[Revision note: Based on Sec. 7.452]
Sec. 29.557 Takeoff cooling test procedures; category A.
For category A rotorcraft, cooling must be shown during takeoff and subsequent climb as follows:
(a) All temperatures must be stabilized while hovering in ground effect with---
(1) All engines at the power necessary for hovering;
(2) The appropriate cowl flap and shutter settings; and
(3) The maximum weight.
(b) After all temperatures have stabilized, the climb must be started at the lowest practicable altitude and must be conducted with one engine inoperative.
(c) All operating engines must be at takeoff r.p.m. and power (or at full throttle when above the takeoff critical altitude) for the same time interval as takeoff power is used for determining the takeoff flight path under Sec. 29.47(c).
(d) At the end of the time interval prescribed in paragraph (c) of this section, the power must be reduced to maximum continuous power and the climb must be continued for at least five minutes after the occurrence of the highest temperature recorded.
(e) All speeds must be those used during determination of the takeoff flight path in accordance with Sec. 29.47 (c).
[Revision note: Based on Sec. 7.453]
Sec. 29.559 Cooling test procedures; category B.
For category B rotorcraft, cooling must be shown during takeoff and subsequent climb, using the following procedures:
(a) All temperatures must be stabilized while hovering in ground effect with---
(1) The power necessary for hovering;
(2) The appropriate cowl flaps and shutter settings; and
(3) The maximum weight.
(b) After all temperatures have stabilized, the climb must be started at the lowest practicable altitude with takeoff power.
(c) Takeoff power must be used for the same time interval as takeoff power is used for determining the takeoff flight path under Sec. 29.49
(d) At the end of the time interval prescribed in paragraph (c) of this section the power must be reduced to maximum continuous power and the climb must be continued for at least five minutes after the occurrence of the highest temperature recorded.
(e) The cooling test must be conducted at an airspeed corresponding to normal operational practice for the configuration being tested. However, if the cooling provisions are sensitive to rotorcraft speed, the most critical airspeed must be used, but need not exceed the speed for best rate of climb with maximum continuous power.
[Revision note: Based on Sec. 7.454]
Sec. 29.561 Hovering cooling test procedures.
The hovering cooling provisions must be shown---
(a) At maximum weight or at the greatest weight at which the rotorcraft is capable of hovering (if less), at sea level, using the power required to hover but not exceeding maximum continuous power, in the ground effect in still air, until at least five minutes after the occurrence of the highest temperature recorded; and
(b) With all engines at maximum continuous power, maximum certificated weight, and at the altitude resulting in zero rate of climb for this configuration, until at least five minutes after the occurrence of the highest temperature recorded.
[Revision note: Based on Sec. 7.455]
INDUCTION AND EXHAUST SYSTEMS
Sec. 29.571 General.
(a) The air induction system for each engine must supply all the air required by that engine under all operating conditions for which certification is requested.
(b) Each engine air induction system must provide air for proper fuel metering and mixture distribution with the induction system valves in any position.
(c) No air intake may open within the engine accessory section or within other areas of any powerplant compartment where emergence of backfire flame would constitute a fire hazard.
(d) Each engine must have an alternate air source.
(e) Each alternate air intake must be located to prevent the entrance of rain, ice, or other foreign matter.
[Revision note: Based on Sec. 7.460]
Sec. 29.573 Induction system icing protection.
Each engine air induction system must have means to prevent and eliminate icing. Unless this is accomplished by other means, it must be shown that, in air free of visible moisture at a temperature of 30 degrees F., and with the engines at 60 percent of maximum continuous power---
(a) Each rotorcraft with sea level engines using conventional venturi carburetors has a preheater that can provide a heat rise of 90 degrees F.;
(b) Each rotorcraft with sea level engines using carburetors tending to prevent icing has a preheater that can provide a heat rise of 70 degrees F.;
(c) Each rotorcraft with altitude engines using conventional venturi carburetors has a preheater capable of providing a heat rise of 120 degrees F.; and
(d) Each rotorcraft with altitude engines using carburetors tending to prevent icing has a preheater that can provide a heat rise of 100 degrees F.
[Revision note: Based on Sec. 7.461]
Sec. 29.575 Carburetor air preheater design.
Each carburetor air preheater must be designed and constructed to---
(a) Ensure ventilation of the preheater when the engine is operated with cold air;
(b) Allow inspection of all exhaust manifold parts that it surrounds; and
(c) Allow inspection of critical portions of the preheater itself.
[Revision note: Based on Sec. 7.462]
Sec. 29.577 Induction system ducts.
(a) Each induction system duct upstream of the first stage of the supercharger must have a drain to prevent the hazardous accumulation of fuel and moisture in the ground attitude. No drain may discharge where it might cause a fire hazard.
(b) Sufficient strength must be incorporated in each duct to prevent induction system failure from normal back-fire conditions.
(c) Each duct connected to components between which relative motion could exist must have provisions for flexibility.
(d) Each duct within any fire zone for which a fire-extinguishing system is required must be at least---
(1) Fireproof, if it passes through any firewall: or
(2) Fire resistant, for other ducts.
[Revision note: Based on Sec. 7.463]
Sec. 29.579 Induction system screens.
If induction system screens are used--
(a) Each screen must be upstream of the carburetor;
(b) No screen may be in any portion of the induction system that is the only passage through which air can reach the engine, unless it is so located that it can be deiced by heated air;
(c) No screen may be deiced by alcohol alone; and
(d) It must be impossible for fuel to impinge upon any screen.
[Revision note: Based on Sec. 7.464]
Sec. 29.581 Carburetor air cooling.
It must be shown under Sec. 29.553 that each installation using two-stage super-chargers has means to maintain the air temperature, at the carburetor inlet, at or below the maximum established value.
[Revision note: Based on Sec. 7.465]
Sec. 29.583 Inter-coolers and after-coolers.
Each inter-cooler and after-cooler must be able to withstand all vibration, inertia, and air pressure loads to which it would be subjected in operation.
[Revision note: Based on Sec. 7.466]
Sec. 29.585 Exhaust system and installation components.
(a) General. Each exhaust system must be constructed and arranged to ensure safe disposal of exhaust gases without a fire hazard or carbon monoxide contamination in any personnel compartment, and to conform with the following:
(1) Unless appropriate precautions are taken, no exhaust system part may be in hazardous proximity to any portion of a system carrying flammable fluids or vapors, nor may it be located under any portion of such system that is subject to leakage.
(2) Each component upon which hot exhaust gases could impinge, or which could be subjected to high temperatures form exhaust system parts, must be fireproof. Exhaust system components must be separated by means of fireproof shields from adjacent portions of the rotorcraft that are outside the engine compartment.
(3) No exhaust gases may discharge so as to cause a fire hazard with respect to any flammable fluid vent or drain.
(4) No exhaust gases may discharge where they will cause a glare seriously affecting pilot vision at night.
(5) Each exhaust system component must be ventilated to prevent points of excessively high temperature.
(6) Each exhaust shroud must be ventilated or insulated to avoid, during normal operation, a temperature high enough to ignite any flammable fluids or vapors external to the shroud.
(b) Exhaust piping. All exhaust piping must be resistant to heat and corrosion, and must have provisions to prevent failure due to expansion by operating temperatures. In addition---
(1) All piping must be supported to withstand all vibration and inertia loads to which it would be subjected in operation; and
(2) Each portion of piping that is connected to components between which relative motion could exist must have provisions for flexibility.
(c) Exhaust heat exchanger. Each exhaust heat exchanger must be constructed and installed to withstand all vibration, inertia, and other loads to which it would be subjected in operation. In addition---
(1) Each exchanger must be suitable for continued operation at high temperatures and resistant to corrosion from exhaust gases;
(2) Provision must be made for the inspection of all critical portions of each exchanger;
(3) Each exchanger must incorporate cooling provisions whenever it is subject to contact with exhaust gases; and
(4) No exhaust heat exchanger or muff may incorporate any stagnant area or liquid traps that would increase the possibility of ignition of flammable fluids or vapors that might be present in case of the failure or malfunction of components carrying flammable fluids.
(d) Exhaust heating of ventilating air. If an exhaust heat exchanger is used for heating ventilating air used by personnel---
(1) A secondary heat exchanger must be provided between the primary exhaust gas heat exchanger and the ventilating air system; or
(2) Other means must be used to preclude the harmful contamination of the ventilating air.
[Revision note: Based on Sec. 7.467]
POWERPLANT CONTROLS AND ACCESSORIES
Sec. 29.601 Powerplant controls; general.
(a) Powerplant controls must be located and arranged in accordance with Sec. 29.357 and marked in accordance with Sec. 29.861.
(b) Each control must be located so that it cannot be inadvertently operated by personnel entering, leaving, or making normal movements in the cockpit.
(c) Each flexible powerplant control must be approved.
(d) Each control must be able to maintain any set position without constant attention by flight personnel and without creep due to control loads or vibration.
(e) Each control must have sufficient strength and rigidity to withstand all operating loads without excessive deflection.
[Revision note: Based on Sec. 7.470]
Sec. 29.603 Throttle and antidetonant injection system controls.
(a) A separate throttle control must be provided for each engine.
(b) All throttle controls must be arranged to allow ready synchronization of all engines by--
(a) The separate control of each engine; and
(2) The simultaneous control of all engines.
(c) Each throttle control must provide a positive and immediately responsive means of controlling its engine.
(d) Each antidetonant injection system control must be incorporated in the throttle controls. However, the antidetonant injection pump may have a separate control.
[Revision note: Based on Sec. 7.471]
Sec. 29.605 Ignition switches.
(a) The ignition switches must provide for the control of each ignition circuit on each engine.
(b) Mans must be provided for quickly shutting off all ignition by the grouping of switches or by a master ignition switch.
(c) Each master ignition switch must have a guard to prevent its inadvertent operation.
[Revision note: Based on Sec. 7.472]
Sec. 29.607 Mixture controls.
(a) If mixture controls are provided, a separate control must be provided for each engine, and the controls must be arranged to allow---
(1) The separate control of each engine; and
(2) The simultaneous control of all engines.
(b) Each intermediate position of the mixture controls that corresponds to a normal operating setting must be identifiable by feel and sight.
[Revision note: Based on Sec. 7.473]
Sec. 29.609 Carburetor air preheat controls.
The carburetor air temperature of each engine must be controlled by separate controls.
[Revision note: Based on Sec. 7.474]
Sec. 29.611 Supercharger controls.
Each supercharger control must be accessible to the pilots or, if a separate flight engineer station with a control panel is provided, to the flight engineer.
[Revision note: Based on Sec. 7.475]
Sec. 29.613 Rotor brake controls.
It must be impossible to inadvertently apply the rotor brake in flight, and there must be means to warn the crew if the rotor brake has not been completely released before takeoff.
[Revision note: Based on Sec. 7.476]
Sec. 29.615 Powerplant accessories.
(a) Each engine mounted accessory must be approved for mounting on the engine concerned and use the provisions on the engine for mounting.
(b) Each item of electrical equipment subject to arcing or sparking must be installed to minimize the probability of igniting flammable fluids or vapors that might be present.
(c) If, in the case of its malfunction, the continued rotation of an engine-driven cabin supercharger or any remote accessory driven by the engine will be a hazard, there must be means to prevent its hazardous rotation without interference to the continued operation of the engine.
[Revision note: Based on Sec. 7.477 (less note following)]
Sec. 29.617 Engine ignition systems.
(a) Each battery ignition system must be supplemented with a generator that is automatically available as an alternate source of electrical energy to allow continued engine operation in case of depletion of any battery.
(b) Each battery and generator must have enough capacity to meet the simultaneous demands of the engine ignition system and the greatest demands of any rotorcraft electrical system component drawing energy from the same source.
(c) The design of the engine ignition system must consider the effect of an inoperative generator, and the effect of a depleted battery with the generator running at normal speed.
(d) If only on e battery is provided, the design of the engine ignition system must consider the effect of a depleted battery with the generator running at idling speed.
(e) Magneto ground wires for separate ignition circuits that lie on the engine side of the firewall must be installed, or protected, to minimize the probability of the simultaneous failure of two or more wires as a result of mechanical damage, electrical fault, or other cause.
(f) No ground wire for any engine may be routed through a fire zone of another engine unless all parts of that wire within that zone are fireproof.
(g) Each ignition system must be independent of any electrical circuit not used for analyzing the operation of that system.
(h) Means must be provided to warn flight personnel if the malfunctioning of any part of the electrical system is causing the continuous discharging of any battery necessary for engine ignition.
[Revision note: Based on Sec. 7.478]
POWERPLANT FIRE PROTECTION
Sec. 29.631 Designated fire zones; regions included.
(a) Designated fire zones are ---
(1) The engine power section;
(2) The engine accessory section;
(3) Any complete powerplant compartment in which no isolation is provided between the engine power section and the engine accessory section;
(4) Any auxiliary power unit compartment; and
(5) Any fuel-burning heater and other combustion equipment installations described in Sec. 29.383.
(b) Each designated fire zone must meet the requirements of Secs. 29.633 through 29.647.
[Revision note: Based on Sec. 8.480]
Sec. 29.633 Flammable fluids.
(a) No tanks or reservoirs that are a part of any system containing flammable fluids or gases may be located in a designated fire zone unless the fluid contained, the design of the system, the materials used in the tank and its supports, the shutoff means, and all connections, lines, and controls provide an equal degree of safety.
(b) Each fuel tank must be isolated from the engines by a firewall or shroud.
(c) At least one-half inch of clear airspace must be provided between any tank or reservoir and any firewall or shroud isolating a designated fire zone, unless equivalent means are used to protect against heat transfer from the fire zone to the flammable fluid.
(d) An absorbent material close to flammable fluid system components that might be subject to leakage must be covered or treated to prevent the absorption of hazardous quantities of fluids.
[Revision note: Based on Sec. 8.481]
Sec. 29.635 Shutoff means.
(a) Except for lines forming an integral part of any engine, and except for engine oil systems in category B rotorcraft using engines of less than 500 cubic inches displacement, means must be provided to shut off or otherwise prevent hazardous quantities of fuel, oil, deicer, and other flammable fluids from flowing into, within, or through any designated fire zone.
(b) The closing of any fuel shutoff valve for any engine may not affect any other engine.
(e) For category A rotorcraft, it must be shown that no hazardous quantity of flammable fluid can drain into any designated fire zone after shutoff has been accomplished, and that the closing of any fuel shutoff valve for an engine does not make any fuel unavailable to any other engine.
(d) The operation of any shutoff may not interfere with the later emergency operation of any other equipment such as the means for declutching the engine from the rotor drive.
(e) Each shutoff must be located outside of a designated fire zone, unless an equal degree of safety is otherwise provided.
(f) Provision must be made to prevent the inadvertent operation of each shutoff and to make it possible for the crew to reopen it in flight.
[Revision note: Based on Sec. 8.482]
Sec. 29.637 Lines and fittings.
(a) Except as provided in paragraph (b), each line and fitting carrying flammable fluids in any area subject to engine fire conditions must conform to the following:
(1) The line and fitting must be at least fire resistant:
(2) If flexible hose is used, all assemblies of hose and end fittings must be approved.
(b) Paragraph (a) of this section does not apply to
(1) Lines and fittings forming an integral part of an engine; and
(2) Vent and drain lines, and their fittings, whose failure will not result in, or add to, a fire hazard.
[Revision note: Based on Sec. 8.483]
Sec. 29.639 Fire-extinguishing systems.
(a) General. Each rotorcraft, other than category B rotorcraft with engines of 1,500 cubic inches displacement or less, must have fire extinguishing systems for all designated fire zones. The fire-extinguishing system for each powerplant must be able to simultaneously protect all zones of the powerplant compartment for which protection is provided. For multiengine rotorcraft, the fire-extinguishing system, the quantity of extinguishing agent, and the rate of discharge must provide at least two adequate discharges, or, in the case of auxiliary power units and combustion equipment, at least one adequate discharge. For multiengine rotorcraft, it must be possible to direct both discharges of any engine fire-extinguishing system to any main engine installation. For single engine rotorcraft, the quantity of extinguishing agent and the rate of discharge must provide at least one adequate discharge for the engine compartment.
(b) Fire-extinguishing agents. Each extinguishing agent used must be methyl bromide, carbon dioxide, or an agent that has equal extinguishing action. In addition---
(1) If methyl bromide, carbon dioxide, or any other toxic extinguishing agent is used, it must be shown by test that entry of harmful concentrations of fluid or fluid vapors into any personnel compartment (due to leakage during normal operation of the rotorcraft of discharge on the ground or in flight) is prevented, even though a defect may exist in the extinguishing system; and
(2) All methyl bromide containers must be charged with a dry agent and sealed by the fire extinguisher manufacturer or by any other person using appropriate recharging equipment.
(c) Extinguishing agent container pressure relief. Each extinguishing agent container must have a pressure relief to prevent bursting of the container by excessive internal pressures. In addition---
(1) Each discharge line from a relief connection must terminate outside the rotorcraft in a location convenient for inspection on the ground; and
(2) A visual discharge indicator must be provided at the discharge end of each discharge line.
(d) Extinguishing agent container compartment temperature. The temperature of all extinguishing agent containers must be maintained, under all intended operating conditions, to ensure that the pressure in the container does not--
(i) Fall below that level necessary to provide an adequate rate of discharge; or
(2) Rise to a level high enough to create a hazard of premature discharge.
(e) Fire-extinguishing system materials. For each fire extinguishing system---
(1) No materials in the system may react chemically with any extinguishing agent so as to constitute a hazard; and
(2) Each system component in an engine compartment must be fireproof.
[Revision note: Based on Sec. 8.484]
Sec. 29.641 Fire-detector systems.
(a) For rotorcraft other than category B rotorcraft with engines of 900 cubic inches displacement or less, approved quick-acting fire detectors meeting the requirements of this section must be provided in all designated fire zones in numbers and locations that ensure prompt detection of fire in those zones.
(b) Each fire detector must be constructed and installed to ensure its ability to withstand any vibration, inertia, and other loads to which it would be subjected in operation.
(c) No fire detector may be affected by any oil, water, other fluids, or fumes that might be present.
(d) Means must be provided to allow crewmembers to check, in flight, the functioning of each fire-detector system electrical circuit.
(e) All wiring and other components of all fire-detector systems located in engine compartments must be at least fire resistant.
(f) No fire-detector system component for any fire zone may pass through another fire zone, unless-
(1) It is protected against the possibility of false warnings resulting from fire in zones through which it passes; or
(2) All zones involved are simultaneously protected by the same detector and extinguishing systems.
[Revision note: Based on Sec. 8.485]
Sec. 29.643 Firewalls.
(a) Each engine must be isolated by a firewall, shroud, or other equivalent means, from all personnel compartments, structures, controls, rotor mechanisms, and other parts that are---
(1) Essential to controlled landing; and
(2) Not protected under Sec. 29.385.
(b) Each auxiliary power unit, combustion heater, and other combustion equipment to be used in flight, must be isolated from the rest of the rotorcraft by firewalls, shrouds, or other equivalent means.
(c) Each firewall or shroud must be constructed so that no hazardous quantity of air, fluid, or fame can pass from any engine compartment to any other portions of the rotorcraft.
(d) Each opening in the firewall or shroud must be sealed with close-fitting fireproof grommets, bushings, or firewall fittings.
(e) Each firewall and shroud must be fireproof and protected against corrosion.
(f) In complying with this section, account must be taken of the probable path of a fire as affected by the airflow in normal flight and in autorotation.
[Revision note: Based on Sec. 8.486]
Sec. 29.645 Engine cowling and engine compartment covering.
(a) Each cowling and engine compartment covering must be constructed and supported so that it can resist all vibration, inertia, and air loads to which it would be subjected in operation.
(b) All cowling must meet the drainage and ventilation requirements of Sec. 29.647.
(c) On rotorcraft with a diaphragm isolating the engine power section from the engine accessory section, each portion of the accessory section cowling that might be subject to fame in case of fire in the engine power section of the powerplant must-
(1) Be fireproof; and
(2) Meet the requirements of Sec. 29.643.
(d) Each portion of the cowling or engine compartment covering that would be subjected to high temperatures due to its proximity to exhaust system parts or exhaust gas impingement must be fireproof.
(e) Each category A rotorcraft must--
(1) Be designed and constructed so that no fire originating in any fire zone can enter, either through openings or by burning through external skin, into any other zone or region where it would create additional hazards;
(2) Conform with subparagraph (1) of this paragraph with the landing gear retracted (if applicable); and
(3) Have fireproof skin in areas that might be subjected to flame in the event of a fire originating in the engine power or accessory sections.
[Revision note: Based on Sec. 7.487]
Sec. 29.647 Drainage and ventilation of fire zones.
(a) Complete drainage of all portions of each designated fire zone must be provided to minimize the hazards resulting from failure or malfunctioning of any component containing flammable fluids. Drainage must be effective under conditions expected to prevail when drainage is needed and arranged so that no discharged fluid will cause an additional fire hazard.
(b) Each designated fire zone must be ventilated to prevent the accumulation of flammable vapors.
(c) No ventilation opening may be where it would allow the entry of flammable fluids, vapors, or flame from other zones.
(d) Each ventilation means must be arranged so that no discharged vapors will cause an additional fire hazard.
(e) For category A rotorcraft, provision must be made to allow the crew to shut off all sources of forced ventilation in any fire zone (other than the engine power section of the powerplant compartment) unless the amount of extinguishing agent and the rate of discharge are based on the maximum airflow through that zone.
[Revision note: Based on Sec. 7.489]
Subpart F--Equipment
GENERAL
Sec. 29.671 SCOPE.
The basic equipment prescribed in this subpart must be installed in the rotorcraft certification under this Part.
[Revision note: Based on Sec. 7.600 (1st sentence)]
Sec. 29.673 function and installation.
Each item of installed equipment must---
(a) Be of a kind and design appropriate to its intended function;
(b) Be labeled as to its identification, function, or operating limitation, or any combination of these, as applicable;
(c) Be installed in accordance with limitations specified for that equipment; and
(d) Function properly in the rotorcraft.
[Revision note: Based on Sec. 7.601]
Sec. 29.675 Required basic equipment.
(a) General. Each rotorcraft must contain all basic equipment prescribed in paragraphs (b) through (d) of this section.
(b) Flight and navigational instruments. The required flight and navigational instruments include the following:
(1) Air speed indicating system.
(2) Sensitive altimeter.
(3) Clock (sweep-second)
(4) Free-air temperature indicator.
(5) Non-tumbling gyroscopic bank and pitch indicator.
(6) Gyroscopic rate-of-turn indicator with bank indicator.
(7) Gyroscopic direction indicator.
(8) Magnetic direction indicator.
(9) Rate-of climb (vertical speed) indicator.
(c) Powerplant instruments. The required power plant instruments include the following:
(1) For each rotorcraft--
(i) A carburetor air temperature indicator for each engine;
(ii) A cylinder head temperature indicator for each air-cooled engine, or coolant temperature indicator for each liquid-cooled engine;
(iii) A fuel quantity indicator for each fuel tank;
(iv) If an engine can be supplied with fuel from more than one tank, a warning device to indicate low fuel in each tank, that is, to indicate when a five minute usable fuel supply remains when the rotorcraft is in the most adverse fuel feed condition for that tank, regardless of whether that condition can be sustained for the five minutes;
(v) A manifold pressure indicator for each engine, if altitude engines are used;
(vi) an oil pressure warning device for each pressure-lubricated gearbox to indicate when the oil pressure falls below a safe value;
(vii) An oil quantity indicator for each oil tank and each rotor drive gearbox, if lubricant is self contained;
(viii) An oil temperature indicator for each engine;
(ix) An oil temperature warning device to indicate when the oil temperature exceeds a safe value in each main rotor drive gearbox (including all gearboxes essential to rotor phasing) that has an oil system independent of the engine oil system;
(x) A tachometer for each engine which, if combined with an instrument required by subdivision (xi) Of this subparagraph, indicates rotor r.p.m. during autorotation; and
(xi) At least one tachometer to indicate, as applicable, the r.p.m. of the single main rotor, the common r.p.m. of all main rotors whose speeds cannot vary appreciably with respect to each other, or the r.p.m. of each main rotor whose speed can vary appreciably with respect to that of another main rotor.
(2) For each category A rotorcraft--
(i) An individual oil pressure indicator for each engine, and either an independent warning device for each engine or a master warning device for each engine or a master warning device for all engines with means for isolating the individual warning circuit from the master warning device;
(ii) An individual fuel pressure indicator for each engine, and either an independent warning device for each engine or a master warning device for all engines with means for all engines with means for isolating the individual warning circuit form the master warning device; and
(iii) Fire warning indicators.
(3) For all category B rotorcraft---
(i) An individual oil pressure indicator for each engine;
(ii) An individual fuel pressure indicator for each engine; and
(iii) Fire warning indicators, when fire detection is required.
(d) Miscellaneous equipment. The required miscellaneous equipment includes the following:
(1) An approved seat for each occupant.
(2) An approved individual safety belt for each occupant.
(3) A master switch arrangement for all electrical circuits other than ignition.
(4) Sufficient sources of electrical energy.
(5) Electrical protective devices.
(6) Hand fire extinguishers.
(7) A windshield wiper or equivalent device for each pilot station.
(8) A two-way radio communication system.
(9) An ignition switch for each, and for all, engines.
[Revision note: Based on Sec. 7.602 through 7.605]
Sec. 29.677 Equipment, systems, and installations.
(a) General. All equipment, systems, and installations whose functioning is necessary to show compliance with any regulation in this subchapter must be designed and installed to---
(1) Ensure that they will reliably perform their intended functions under all reasonably foreseeable operating conditions; and
(2) Guard against hazards to the rotorcraft in the event of their malfunctioning or failure under the same conditions.
For electrical systems, equipment, and installations, critical environmental conditions must be considered in showing compliance with this paragraph.
(b) Category A; power supply. Each installation whose functioning is requires a power supply is considered for the purpose of this section to be an "essential load" on the power supply. The power sources and the system must be able to supply the following power loads in probable operating combinations and for probable durations:
(1) All loads connected to the system with the system functioning normally
(2) All essential loads, after failure of any one prime mover, power converter, or energy storage device.
(3) All essential loads, after---
(i) Failure of any one engine, on two or three-engine rotorcraft; or
(ii) Failure of any two engines, on rotorcraft with four or more engines.
(c) Category A; assumptions. In determining compliance with paragraphs (b) (2) and (8) of this section, the power loads may be assumed to be reduced in accordance with a monitoring procedure that is consistent with safety in the kinds of operations authorized. Loads not required for controlled flight need not be considered for the two-engine-inoperative condition on rotorcraft with four or more engines as prescribed in paragraph (b) (3) of this section.
[Revision note: Based on Sec. 7.606 and 7.625 (a)]
INSTRUMENTS; INSTALLATION
Sec. 29.691 Arrangement and visibility.
(a) Each flight, navigation, and powerplant instrument for use by any pilot must be easily visible to him from his station with the minimum practicable deviation from his normal position and line of vision when he is looking forward along the flight path.
(b) Each instrument necessary for safe operation, including the airspeed indicator, gyroscopic direction indicator, gyroscope bank and pitch indicator, altimeter, rate-of-climb indicator, rotor tachometers, and manifold pressure indicator, must be grouped and centered as nearly as practicable about the vertical plane of the pilot's forward vision.
(c) All other required powerplant instruments must be closely grouped on the instrument panel.
(d) All identical powerplant instruments for the engines to which they relate.
(e) Each powerplant instrument vital to safe operation must be plainly visible to appropriate crewmembers.
(f) Instrument panel vibration may neither damage, nor seriously impair, the readability or accuracy of any instrument.
[Revision note: Based on Sec. 7.611]
Sec. 29.693 Flight and navigation instruments.
(a) Airspeed indicating system. Each airspeed indicating system must conform to the following:
(1) Each airspeed indicating instrument must be calibrated to indicate true airspeed at sea level in standard atmosphere with a minimum practicable instrument calibration error when the corresponding pilot and static pressures and applied to the instrument.
(2) Each system must be calibrated to determine the system error, that is, the relation between IAS and CAS. This calibration must be determined, over an appropriate range of speeds---
(i) In flight, for the flight conditions of climb, level flight, and autorotation; and
(ii) In ground effect, during the accelerated takeoff run.
(3) For multiengine rotorcraft, the airspeed error of the installation, including the airspeed indicator instrument calibration error, may not exceed three percent, or five m.p.h. whichever is greater--
(i) Throughout the speed range in level flight at all forward speeds of 10 m.p.h. below the takeoff climbout safety speed to 10 m.p.h. above the best rate-of-climb speed.
(4) For single engine rotorcraft, calibration of the airspeed indicator must be made in flight at all forward speeds of 10 m.p.h. or over. The airspeed error of the installation, including the airspeed indicator instrument calibration error, may not exceed three percent, or five m.p.h., whichever is greater, at any forward speed above 80 percent of the climbout speed.
(5) Each system must be arranged so far as practicable to prevent malfunctioning or serious error due to the entry of moisture, dirt, or other substances.
(6) Each system must have a heated pilot tube or an equivalent means of preventing malfunctioning due to icing.
(b) Static air vent and pressure altimeter systems. Each static air vent and pressure altimeter system must conform to the following:
(1) Each instrument with static air case connections must be vented to the outside atmosphere through an appropriate piping system.
(2) Each vent must be where its orifices will be least affected by airflow variation, moisture, or other foreign matter.
(3) Each system must be airtight, except for the vent into the atmosphere.
(4) Each pressure altimeter must be approved and calibrated to indicate pressure altitude in standard atmosphere with a minimum practicable calibration error when the corresponding static pressures are applied.
(5) The design and installation of each altimeter system must be such that the error in indicated pressure altitude at sea level in standard atmosphere, excluding instrument calibration error, does not result in a reading more than 30 feet high nor more than 30 feet low in the level flight speed range from 0 m.p.h. to 0.9 Vh.
(c) Magnetic direction indicator. The magnetic direction indicator must be installed so that its accuracy is not excessively affected by the rotorcraft's vibration or magnetic fields. The calibrated installation must be such that the deviation in level flight does not exceed 10 degrees on any heading. A suitable calibration placard must be provided as specified in Sec. 29.853.
(d) Automatic pilot system. If an automatic pilot system is installed, it must be approved and must conform to the following:
(1) Each system must be designed so that the automatic pilot can---
(i) Be quickly and positively disengaged by the human pilots to prevent it from interfering with their control of the rotorcraft; or
(ii) Be sufficiently overpowered by one human pilot to enable him to control the rotorcraft.
(2) A means must be provided to indicate readily to the pilot the alignment of the actuating device in relation to the control system it operates, except when automatic synchronization is provided.
(3) Each manually operated control for the system's operation must be readily accessible to the pilots.
(4) The system must be designed and adjusted so that, within the range of adjustment available to the human pilot, it cannot produce hazardous loads on the rotorcraft or create hazardous deviations in the flight path under any condition of flight appropriate to its use, either during normal operation or in the event of malfunctioning, assuming that corrective action is initiated within a reasonable period of time.
(e) Category A; instruments using a power supply. For category A rotorcraft, each required flight instrument using a power supply must have two independents sources of power, a means of selecting either power source, and a means of indicating the adequacy of the power being supplied. The installation and power supply system must be such that failure of any flight instrument connected to one source, or of the energy supply from one source, or a fault in any part of the power distribution system, will not interfere with the proper supply of energy from the other source.
(f) Duplicate instrument systems. If duplicate flight instruments are required by any operating rule in this chapter---
(1) Each operating system for flight instruments used by the first pilot and required to be duplicated at other flight crew stations must be independent of the operating system provided for other flight crew stations;
(2) Only the required flight instruments and duplicates of required instruments provided for the first pilot need be connected to the operating system provided for the first pilot; and
(3) If instruments other than required instruments and their duplicates are connected to systems other than the first pilot's operating system, provision must be made to disconnect or isolate them in flight.
[Revision note: Based on Sec. 7.612]
Sec. 29.695 Powerplant instruments.
(a) Instrument lines. Instrument lines must conform to the provisions of Secs. 29.505 and 29.637. Each line carrying flammable fluids or gases under pressure must have restricted orifices or equivalent safety devices at the source of the pressure to prevent the escape of excessive fluid or gas in case of line failure.
(b) Fuel quantity indicator. Means must be provided to indicate to the flight crew the quantity, in gallons or in equivalent units, of usable fuel in each tank during flight. In addition---
(1) All tanks with interconnected out-- lets and airspaces must be treated as one tank for the purpose of providing separate indicators;
(2) Each exposed sight gauge must be protected against damage; and
(3) Each fuel quantity indicator must be calibrated to read "zero" during level flight when the quantity of fuel remaining in the tank is equal to the unusable fuel supply determined under Sec. 29.459.
(c) Fuel flowmeter system. If a fuel flowmeter system is installed, each metering component must include a means for by-passing the fuel supply if malfunctioning of that component severely restricts fuel flow.
(d) Oil quantity indicator. A stick gauge or equivalent means must be provided to indicate the quantity of oil---
(1) In each tank, and
(2) In each transmission gearbox.
[Revision note: Based on Sec. 7.613]
ELECTRICAL SYSTEMS AND EQUIPMENT
Sec. 29.705 Electrical system capacity.
The required generating capacity and the number and kind of power sources must---
(a) Be determined by an electrical load analysis; and
(b) Conform with Sec. 29.677.
[Revision note: Based on Sec. 7.621]
Sec. 29.707 Generating system.
(a) The generating system includes all electrical power sources, main power busses, and transmission cables, and all associated control, regulation, and protective devices.
(b) Each system must be designed to that---
(1) All power sources function properly when independent and when connected in combination;
(2) The failure or malfunctioning of any power source cannot create a hazard or impair the ability of the remaining sources to supply essential loads;
(3) The system voltage and frequency (as applicable) at the terminals of all essential load equipment can be maintained within the limits for which the equipment is designed, during all probable operating conditions;
(4) System transients initiated by switching, fault clearing, or other causes, do not make essential loads inoperative, and do not cause a smoke of fire hazard;
(5) Means accessible in flight to appropriate crewmembers are provided for the individual and collective disconnection of all electrical power sources from the main bus; and
(6) Means are provided to indicate to appropriate crewmembers all generating system quantities that are essential for the safe operation of the system, such as the voltage and current supplied by each generator.
[Revision note: Based on Sec. 7.622]
Sec. 29.709 Distribution system.
(a) The distribution system includes all distribution busses, their associated feeders, and all control and protective devices.
(b) Each system must be designed so that----
(1) For category A rotorcraft, individual distribution systems ensure that essential load circuits can be supplied in the event of reasonably probable faults or open circuits; and
(2) Where two independent sources of electrical power for particular equipment or systems are required by this subchapter, their energy supply is ensured.
[Revision note: Based on Sec. 7.623 )less note following)]
Sec. 29.711 Electrical protection.
Automatic protective devices must be provided to minimize distress to the electrical system and hazard to the rotorcraft in the event of wiring faults or serious malfunctioning of the system or connected equipment. In addition---
(a) For category A rotorcraft, means must be provided in the generating system to automatically de-energise and disconnect form the main bus any power source developing hazardous overvoltage;
(b) Each resettable circuit protective device must be designed so that, when an overload or circuit fault exists, it will open the circuit irrespective of the position of the operating control;
(c) If the ability to reset a circuit breaker or to replace a fuse is essential to safety in flight, that circuit breaker or fuse must be so located and identified that i can be readily reset or replaced in flight;
(d) Each circuit for essential loads must have individual circuit protection; and
(e) If fuses are used, there must be spare fuses for use in flight equal to at least 50 percent of the number of fuses of each rating required for complete circuit protection.
[Revision note: Based on Sec. 7.634 (less note following (a))]
Sec. 29.713 Electrical equipment and installations.
(a) All electrical equipment, controls, and wiring must be installed so that the operation of any one unit or system of units will not adversely affect the simultaneous operation of any other electrical unit system essential to safe operation.
(b) All cables must be grouped, routed, and spaced so that damage to essential circuits will be minimized in the event of faults in heavy current-currying cables.
(c) Storage batteries must be designed and installed as follows:
(1) Safe cell temperatures and pressures must be maintained during all probable charging and discharging conditions. No uncontrolled increase in cell temperature may result when the battery is recharged (after previous complete discharge)--
(i) At maximum regulated voltage;
(ii) During a flight of maximum duration; and
(iii) Under the most adverse cooling condition likely to occur in service.
(2) Compliance with subparagraph (1) of this paragraph must be shown in tests unless experience with similar batteries and installations has shown that maintaining safe cell temperatures and pressures presents no problem.
(d) No explosive or toxic gases emitted by any battery in normal operation, or as the result of any probable malfunction in the charging system or battery installation, may accumulate in hazardous quantities within the rotorcraft.
(e) No corrosive fluids or gases that may escape from the battery may damage surrounding rotorcraft structures or adjacent essential equipment.
[Revision note: Based on Sec. 7.625 less (a))]
Sec. 29.715 Electrical system fire and smoke protection.
All electrical cables, terminals, and equipment that are necessary in emergency procedures, and that are in a designated fire zone, must---
(a) Be at least fire resistant: and
(b) Conform to the applicable provisions of Secs. 29.367 (d) and 29.387.
[Revision note: Based on Sec. 7.626]
Sec. 29.717 Electrical system tests.
(a) When laboratory tests of the electrical system are conducted---
(1) The tests must be performed on a mock-up using the same generating equipment complement as in the rotorcraft;
(2) All equipment must simulate the electrical characteristics of the distribution wiring and connected loads necessary for valid test results; and
(3) All laboratory generator drives must simulate the actual prime movers on the rotorcraft with respect to their reaction to generator loading, including loading due to faults.
(b) For each flight condition that can not be simulated adequately in the laboratory of by ground tests on the rotorcraft, flight tests must be conducted.
[Revision note: Based on Sec. 7.627]
LIGHTS
Sec. 29.727 Instrument lights.
The instrument lights must---
(a) Provide enough illumination to make all instruments, switches, and other devices for which they are provided easily readable; and
(b) Be installed so that---
(1) Their direct rays are shielded from the pilot's eyes; and
(2) No objectionable reflections are visible to the pilot.
[Revision note: Based on Sec. 7.630]
Sec. 29.729 Landing lights.
(a) Each installed landing or hovering light must be approved.
(b) Each landing light must be installed so that--
(1) No objectionable glare is visible to the pilot;
(2) The pilot is not adversely affected by halation; and
(3) It provides the necessary illumination for night operation, including hovering and landing.
(c) At least one separate switch must be provided, as applicable--
(1) For each separately installed light; and
(2) For each group of lights installed at a common location.
[Revision note: Based on Sec. 7.631]
Sec. 29.731 Position light system installation.
(a) General. Each part of each position light system must conform to the applicable requirements of this section and each system as a whole must conform to the requirements of Secs. 29.733 through 29.743.
(b) Forward position lights. Forward position lights must consist of a red and a green light spaced laterally as far apart as practicable and installed forward on the rotorcraft in such a location that, with the rotorcraft in the normal flying position, the red light is on the left side and the green light is on the right side. Each light must be approved.
(c) Rear position light. The rear position light must be a white light mounted as far aft as practicable, and must be approved.
(d) Circuit. The two forward position lights and the rear position light must constitute a single circuit.
(e) Light covers and color filters.
Each light cover or color filter must be at least flame resistant and must be at least flame resistant and must be constructed so that it will not change color or shape or suffer any appreciable loss of light transmission during normal use.
[Revision note: Based on Sec. 7.682
Sec. 29.733 Position light system dihedral angles.
(a) Each forward and rear position light must, as installed, show unbroken light within the dihedral angles described in this section.
(b) Dihedral angle L (left) is formed by two intersecting vertical planes, the first parallel to the longitudinal axis of the rotorcraft, and the other at 110 degrees to the left of the first, as viewed when looking forward along the longitudinal axis.
(c) Dihedral angle R (right) is formed by two intersecting vertical planes, the first parallel to the longitudinal axis of the rotorcraft, and the other at 110 degrees to the right of the first, as viewed when looking forward along he longitudinal axis.
(d) Dihedral angle A (aft) is forward by two intersecting vertical planes making angles of 70 degrees to the right and to the left, respectively, to a vertical plane passing through the longitudinal axis, as viewed when looking aft along the longitudinal axis.
[Revision note: Based on Sec. 7.683]
Sec. 29.735 Position light distribution and intensities.
(a) General. The Intensities prescribed in this section must be provided by new equipment with all light covers and color filters in place. All intensities must be determined with the light source operating at a steady value equal to the average luminous output of the source at the normal operating voltage of the rotorcraft. The light distribution and intensity of each position light must conform to the provisions of paragraph (b) of this section.
(b) Forward and rear position lights. The light distribution and intensities of forward and rear position lights must be expressed in terms of minimum intensities in the horizontal plane, and maximum intensities in overlapping beams, within dihedral angles, L, R, and A, and must conform to the following provisions:
(1) Intensities in the horizontal plane. Each intensity in the horizontal plane, that is, the plane containing the longitudinal axis of the rotorcraft and perpendicular to the plane of symmetry of the rotorcraft, must equal or exceed the values in Sec. 29.737.
(2) Intensities in any vertical plane. Each intensity in any vertical plane, that is, plane perpendicular to the horizontal plane, must equal or exceed the appropriate value in Sec. 29.739, where I is the minimum intensity prescribed in Sec. 29.737 for the corresponding angles in the horizontal plane.
(3) Intensities in overlaps between adjacent signals. No intensity in any overlap between adjacent signals may exceed the values given in Sec. 29.741, except that higher intensities in overlaps are acceptable with the use of main beam intensities substantially greater than the minima specified in Secs. 239.737 and 29.739 if the overlap intensities in relation to the main beam intensities do not adversely affect signal clarity.
[Revision note: Based on Sec. 7.634]
Sec. 29.737 Minimum intensities in the horizontal plane of forward and rear position lights.
Each position light intensity must equal or exceed the applicable values in the following table.
| Dihedral angle | Angle from right or left of longitudinal axis, measured from dead ahead | Intensity (candles) |
| L and R (forward red and green). | 0° to 10°
10° to 20°
20° to 110° | 40
30
5 |
| A (rear white) | 110° to 180° | 20 |
[Revision note: Based on Figure 7-1]
Sec. 29.739 Minimum intensities in any vertical plane of forward and rear position lights.
Each position light intensity must equal or exceed the applicable values in the following table.
| Angle above or below horizontal: | Intensity |
| 0° | 1.00 I. |
| 0° to 5° | 0.90 I. |
| 5° to 10° | 0.80 I. |
| 10° to 15° | 0.70 I. |
| 15° to 20° | 0.50 I. |
| 20° to 30° | 0.30 I. |
| 30° to 40° | 0.10 I. |
| 40° to 90° | 0.05 I. |
[Revision note: Based on Figure 7-2]
Sec. 29.741 Maximum intensities in overlapping beams of forward and rear position lights.
No position light intensity may exceed the applicable values in the following table, except as provided in Sec. 29.735(b) (3).
| Maximum intensity | |
Overlaps | | |
| Area A
(candles) | Area B
(candles) |
| Green in dihedral angle L | 10 | 1 |
| Red in dihedral angle R | 10 | 1 |
| Green in dihedral A | 5 | 1 |
| Red in dihedral A | 5 | 1 |
| Rear white in dihedral angle L | 5 | 1 |
| Rear white in dihedral angle R | 5 | 1 |
Where---
(a) Area A includes all directions in the adjacent dihedral angle that pass through the light source and intersect the common boundary plane at more than 10 degrees but less than 20 degrees; and
(b) Area B includes all directions in the adjacent dihedral angle that pass through the light source and intersect the common boundary plane at more than 20 degrees.
[Revision note: Combines Figure 7-3 and note following]
Sec. 29.743 color specifications.
Each position light color must have the applicable International Commission on Illumination chromaticity coordinates as follows:
(a) Aviation red---
y is not greater than 0.335; and
z is not greater than 0.002.
(b) Aviation green--
x is not greater than 0.440--0.320y;
x is not greater than y--0.170; and
y is not less than 0.390--0.170x.
(c) Aviation white--
x is not less than 0.350; and
x is not greater than 0.540.
y-ye is not numerically greater than 0.01, ye being the y coordinate of the Planckian radiator for which Ze =Z.
[Revision note: Based on Sec. 7.635]
Sec. 29.745 Riding light.
(a) Each installed riding light must be able to----
(1) Show a white light for at least two miles at night under clear atmospheric conditions; and
(2) Show a maximum practicable unbroken light with the rotorcraft on the water.
(b) Externally hung lights are allowed.
[Revision note: Based on Sec. 7.636]
Sec. 29.747 Anticollision light system.
(a) General. If certification for night operation is requested, the rotorcraft must have an anticollision light system that---
(1) Consists of one or more approved anticollision light so located that their emitted light will not adversely affect the crew's vision or detract from the conspicuity of the position lights; and
(2) Conforms with the provisions of paragraphs (b) through (f) of this section.
(b) Field of coverage. The system must consist of enough lights to illuminate all vital areas around the rotorcraft, with due consideration of the physical configuration and flight characteristics of the rotorcraft. The field of coverage must extend in all directions within at least 30 degrees above and 30 degrees below the horizontal plane of the rotorcraft, except that there may be solid angles of obstructed visibility totaling not more than 0.5 steradians.
(c) Flashing characteristics. The arrangement of the system, that is, the number of light sources, beam width, speed or rotation, and other characteristics, must give an effective flash frequency of not less than 40, nor more than 100, cycles per minute. The effective flash frequency is the frequency at which the rotorcraft's complete anticollision light system is observed from a distance, and applies to all sectors of light including all overlaps that exist when the system consists of more than one light source. In overlaps, flash frequencies may exceed 100, but not 180, cycles per minute.
(d) Color. The color of each anticollision light must be aviation read and must conform to Sec. 29.743(a).
(e) Light intensity. The minimum light intensities in all vertical planes, measured with the red filter and expressed in terms of "effective" intensities, must conform to paragraph (f) of this section. The following relation must be assumed:
where:
Ie= effective intensity (candles).
I(t) = instantaneous intensity as a function of time.
t2 -t1= flash time interval (seconds).
Normally, the maximum value of effective intensity is obtained when t2 and t1 are so chosen that the effective intensity is equal to the instantaneous intensity at t2 and t1.
(f) Minimum effective intensities for anticollision lights. Each anticollision light effective intensity must equal or exceed the applicable values in the following table.
| Angle above or below the horizontal plans: | Effective intensity (candles) |
| 0° to 5° | 100 |
| 5° to 10° | 60 |
| 10° to 20° | 30 |
| 20° to 30° | 10 |
[Revision note: Combines Sec. 7.637 and Figure 7-4]
SAFETY EQUIPMENT
Sec. 29.761 Accessibility.
All required safety equipment to be used by the crew in an emergency, such as flares and automatic liferaft releases, must e readily accessible.
[Revision note: Based on Sec. 7.640]
Sec. 29.763 Flares.
(a) If parachute flares are installed--
(1) Each flare must be approved; and
(2) The rotorcraft structure must be able to withstand all recoil loads involved in the ejection of the flares.
(b) Each flare must be installed so that---
(1) It is releasable from the pilot compartment;
(2) The probability of accidental discharge is minimized; and
(3) Ejection does not endanger the rotorcraft or its occupants.
Compliance with paragraph (b) (3) of this section must be shown in flight.
[Revision note: Combines Secs. 7.641 and 7.642]
Sec. 29.765 Safety belts; passenger warning device.
(a) Each safety belt must be approved.
(b) When means are provided to indicate to the passengers when safety belts should be fastened, the device must be installed so that it can be operated from either pilot seat.
[Revision note: Based on Sec. 7.643]
Sec. 29.767 Emergency flotation and signaling equipment.
(a) General. All emergency flotation and signaling equipment required by any operating rule of this chapter must conform with this section.
(b) Liferafts. Each liferaft must be approved. In addition---
(1) Unless excess rafts of enough capacity are provided, the buoyancy and seating capacity beyond the rated capacity of the rafts must accommodate all occupants of the rotorcraft in the event of a loss of one raft of the largest rated capacity;
(2) Each raft must have a trailing line, and must have a static line designed to hold the raft near the rotorcraft but to release it if the rotorcraft becomes totally submerged; and
(3) Each raft must have obviously marked operating instructions.
(c) Liferaft equipment. Approved survival equipment must be attached to each liferaft and marked for identification and method of operation.
(d) Long-range signaling devices. An approved long-range signaling device must be provided for use in one liferaft.
(e) Life preservers. Each life preserver must be approved.
[Revision note: Based on Sec. 7.644 (less note following (b))]
Sec. 29.769 Stowage of safety equipment.
(a) General. Stowage provisions for all required emergency equipment must be furnished and must---
(1) Be arranged so that the equipment is directly accessible and its location is obvious;
(2) Protect all safety equipment from inadvertent damage; and
(3) Be marked conspicuously to identify the contents and facilitate removal of the equipment.
(b) Emergency exit descent device. The stowage provisions for the emergency exit descent device required by Sec. 29.365 (f) (6) must be at the exits for which they are intended.
(c) Liferafts. Liferafts must be stowed near exits through which the rafts can be launched during an unplanned ditching. Rafts automatically or remotely released on the outside of the rotorcraft must be attached to the rotorcraft by the static line prescribed in Sec. 29.767 (b) (2).
(d) Long-range signaling device. The stowage provisions for the long-range signaling device required by Sec. 29.767(d) must be near an exit available during an unplanned ditching.
(e) Life preservers. Each life preserver must be within easy reach of each occupant while seated.
[Revision note: Based on 7.645]
Sec. 29.771 Protective breathing equipment; oxygen supply.
If protective breathing equipment is required by any operating rule of this chapter--
(a) That equipment must be designed to protect the crew from smoke, carbon dioxide, and other harmful gases while on flight deck duty;
(b) The equipment must include--
(1) Masks covering the eyes, nose, and mouth; or
(2) Masks covering the nose and mouth, plus accessory equipment to cover the eyes; and
(c) A supply of protective oxygen of 10 minutes duration per crewmember must be provided at a pressure altitude of 8,000 feet with a respiratory minute volume of 30 liters per minute BTPD.
[Revision note: Based on Sec. 7.646]
MISCELLANEOUS EQUIPMENT
Sec. 29.781 Hydraulic systems; strength.
(a) Structural loads. Each element of the hydraulic system must be designed to withstand, without detrimental, permanent deformation, all structural loads that may be imposed simultaneously with the maximum operation hydraulic loads.
(b) Proof pressure tests. Each element of the system must be tested to a proof pressure of 1.5 times the maximum pressure to which that element will be subjected in normal operation, without failure, malfunction, or detrimental deformation of any part of the system.
(c) Burst pressure strength. Each hydraulic system element must be designed to withstand pressures sufficiently greater than those prescribed in paragraph (b) of this section to show that the system will not rupture under service conditions.
[Revision note: Based on Sec. 7.650 (less note following)]
Sec. 29.783 Hydraulic systems; design.
(a) General. In addition to the requirements of Sec. 29.677, each hydraulic system must conform with the applicable requirements of this section.
(b) Pressure indication. Means must be provided to indicate the pressure in each main hydraulic power system.
(c) Pressure limiting provisions. Means must be provided to ensure that no pressure in any part of the system will exceed the maximum safe operating pressure of the system, and to prevent excessive pressures resulting from fluid volumetric changes in all lines likely to remain closed long enough for such changes to take place. Consideration must be given to the possibility of detrimental pressures (transient or surge) during operation.
(d) Installation. Each hydraulic line, fitting, and component must be installed and supported to prevent excessive vibration and to withstand inertia loads. Each element of the installation must be protected from abrasion, corrosion, and mechanical damage.
(e) Connections. Means for providing flexibility must be used to connect points in a a hydraulic fluid line between which relative motion or differential vibration exists.
[Revision note: Based on Sec. 7.651]
Sec. 29.785 Hydraulic systems; fire protection
Each hydraulic system using flammable hydraulic fluid must conform with the applicable provisions of Secs. 29.385 and 29.385 and 29.633 through 29.637.
[Revision note: Based on Sec. 7.652]
Sec. 29.787 Radio installation.
(a) All radio communication and navigation equipment installations in the rotorcraft must be free from hazards in themselves, in their method of operation, and in their effects on other components of the rotorcraft, under all critical environmental conditions.
(b) All radio communication and navigation equipment, controls, and wiring must be installed so that operation of any one unit or system of units will not adversely affect the simultaneous operation of any other radio or electronic unit, or system of units, required by any regulation in this chapter.
[Revision note: Based on Sec. 7.653 (less note following)]
Sec. 29.789 Vacuum systems.
(a) Means, in addition to the normal pressure relief, must be provided to automatically relieve the pressure in the discharge lines from the vacuum air pump when the delivery temperature of the air becomes unsafe.
(b) Each vacuum air system line and fitting on the discharge side of the pump that might contain flammable vapors or fluids must conform with Sec. 29.637 if they are in a designated fire zone.
(c) All other vacuum air system components in designated fire zones must be at least fire resistant.
[Revision note: Based on Sec. 7.654]
Subpart G -- Operating Limitations and Information
GENERAL
Sec. 29.811 Operating limitations and information.
Each operating limitation, and all other information concerning the rotorcraft that is necessary for safe operation, must be ---
(a) Included in the rotorcraft flight manual;
(b) Expressed in markings and placards; and
(c) Made available to each crewmember.
[Revision note: Based on Sec. 7.700 (less (a))]
OPERATING LIMITATIONS
Sec. 29.821 Airspeed limitations; general.
When airspeed limitations are function of weight, weight distribution, altitude, rotor speed, power, or other factors, airspeed limits corresponding with all critical combinations of these factors must be established.
[Revision note: Based on Sec. 7.710]
Sec. 29.823 Never-exceed speed VNE°
(a) The never-exceed speed VNE must be established so that it is---
(1) Not less than Vy with all engines at maximum continuous power; and
(2) Not greater than the lesser of---
(i) 0.9V established under Sec. 29.127; and
(ii) 0.9 times the maximums speed shown under Sec. 29.99.
(b) VNE may not vary with altitude and rotor r.p.m., unless the ranges of these variables are large enough to allow an operationally practical and safe variation of VNE°
[Revision note: Based on Sec. 7.711]
Sec. 29.825 Operating speed range.
An operating speed range must be established.
[Revision note: Based on Sec. 7.712]
Sec. 29.827 Rotor speed.
(a) Maximum power off (autorotation). The maximum power-off rotor speed must be established so that it does not exceed 95 percent of the lesser of---
(1) The maximum design r.p.m. determined under Sec. 29.127(b); and
(2) The maximum r.p.m. shown during the type tests.
(b) Minimum power off. The minimum power-off rotor speed must be established so that it is not less than 105 percent of the greater of---
(1) The minimum shown during the type tests; and
(2) The minimum determined by design substantiation.
(c) Minimum power on. The minimum power-on rotor speed must be established so that it is--
(1) Not less than the greater of---
(i) The minimum shown during the type tests; and
(ii) The minimum determined by design substantiation; and
(2) Not higher than a value determined in compliance with Sec. 29.27 (a)(1) and (c) (1).
[Revision note: Based on Sec. 7.713 (less introductory paragraph)]
Sec. 29.829 Powerplant limitations.
(a) General. The powerplant limitations prescribed in this section must be established so that they do not exceed the corresponding limits for which the engines are type certificated.
(b) Takeoff operation. The powerplant takeoff operation must be limited by---
(1) The maximum rotational speed, which may not be greater than--
(i) The maximum value determined by the rotor design; or
(ii) The maximum value shown during the type tests:
(2) The maximum allowable manifold pressure;
(3) The time limit for the use of the power corresponding to the limitations established in subparagraphs (1) and (2) of this paragraph; and
(4) If the time limit in subparagraph (3) of this paragraph exceeds two minutes, the maximum allowable cylinder head, coolant outlet and oil temperatures.
(c) Continuous operation. The continuous operation must be limited by---
(1) The maximum rotational speed, which may not be greater than---
(i) The maximum value determined by the rotor design; or
(ii) The maximum value shown during the type tests;
(2) The maximum allowable manifold pressure;
(3) The maximum allowable cylinder head or coolant outlet and oil temperatures; and
(4) The minimum rotational speed shown in compliance with the rotor speed requirements in Sec. 29.827 (c).
(d) Fuel grade or designating. The minimum fuel grade (for reciprocating engines) or fuel designation (for turbine engines) must be established so that it is not less than that required for the operation of the engines within the limitations in paragraphs (b) and (c) of this section.
(e) Cooling limitations. The maximum sea level temperature established for satisfactory cooling must be shown.
[Revision note: Based on Sec. 7.714]
Sec. 29.831 Limiting height-speed envelope.
If a range of heights exists at any speed, including zero, within which it is not possible to make a safe landing following power failure, the range of heights and its variation with forward speed must be established, together with all other pertinent information, such as kind of landing surface.
[Revision note: Based on Sec. 7.715]
Sec. 29.832 Weight and center of gravity.
The weight and center of gravity limitations determined under Secs. 29.23 and 29.25, respectively, must be established as operating limitations.
[Revision note: Based on Sec. 7.716]
Sec. 29.833 Minimum flight crew.
The minimum flight crew for which certification is requested must be sufficient for safe operation, considering---
(a) The workload on individual crewmembers;
(b) The accessibility and ease of operation of all necessary controls by the appropriate crewmember, and
(c) The kinds of operation authorized under Sec. 29.835.
[Revision note: Based on Sec. 7.717]
Sec. 29.835 Limitations on operation.
The kinds of operation to which a rotorcraft is limited are established on the basis of flight characteristics and installed equipment.
[Revision note: Based on Sec. 7.718]
Sec. 29.837 Maintenance manual.
Each rotorcraft must have a maintenance manual with all information that the applicant considers essential for proper maintenance, including recommended limits on service life or retirement periods for major components. These components must be identified by serial number or equivalent means.
[Revision note: Based on Sec. 7.719]
MARKINGS AND PLACARDS
Sec. 29.847 General.
(a) The rotorcraft must contain---
(1) All marking sand placards specified in Secs. 29.849 through 29.863; and
(2) All additional information, instrument markings, and placards required for the safe operation of rotorcraft with unusual design, operating or handling characteristics.
(b) Each marking and placard prescribed in paragraph (a) of this section---
(1) Must be displayed in a conspicuous place; and
(2) May not be easily erased, disfigured, or obscured.
[Revision note: based on Sec. 7.730]
Sec. 29.849 Instrument markings; general
For each instrument--
(a) When markings are placed on the cover glass of the instrument, provision must be made to maintain the correct alignment of the glass cover with the face of the dial; and
(b) Each arc and line must be of sufficient width, and so located, that it is clearly visible to the pilot.
[Revision note: Based on Sec. 7.731]
Sec. 29.851 Airspeed indicator.
(a) Each airspeed indicator must be marked to show indicated airspeed and to conform with paragraphs (b) through (d) of this section.
(b) A red radial line must be used to indicate the limit beyond which operation is dangerous.
(c) A yellow arc must be used to indicate the precautionary operating range.
(d) A green arc must be used to indicate the safe operating range.
[Revision note: Based on Sec. 7.782]
Sec. 29.853 Magnetic direction indicator.
(a) A placard conforming to this section must be installed on, or close to, the magnetic direction indicator.
(b) The placard must show the calibration of the instrument in level flight with all engines operating.
(c) The placard must state whether the calibration was made with radio receivers on or off.
(d) Each calibration reading must be in terms of magnetic headings in not greater than 45 degree increments.
[Revision note: Based on Sec. 7.783]
Sec. 29.855 Powerplant instruments.
For each required powerplant instrument--
(a) Each maximum and, if applicable, minimum safe operating limit must be marked with a red radial line;
(b) Each normal operating range must be marked with a green are not extending beyond the maximum and minimum safe operating limits;
(c) Each takeoff and precautionary range must be marked with a yellow arc; and
(d) All engine and rotor speed ranges that are restricted because of excessive vibration must be marked with red arcs.
[Revision note: Based on Sec. 7.734]
Sec. 29.857 Oil quantity indicator.
Each oil quantity indicator must be marked in sufficient increments to indicate readily and accurately the quantity of oil.
[Revision note: Based on Sec. 7.735]
Sec. 29.859 Fuel quantity indicator.
If the unusable fuel supply for any tank exceeds one gallon, or five percent of the tank capacity, whichever is greater, a red arc must be marked on its indicator extending from the calibrated zero reading to the lowest reading obtainable in level flight.
[Revision note: Based on Sec. 7.736 (less last sentence)]
Sec. 29.861 Control markings.
(a) Each cockpit control must be plainly marked as to its function and method of operation.
(b) For powerplant fuel controls--
(1) Each tank selector control must be marked to indicate, for all crossfeed positions, the position corresponding to each tank controlled;
(2) If safe operation requires the use of any tanks in a specific sequence, that sequence must be marked on, or adjacent to, the selector for those tanks;
(3) Each valve control for each engine of multiengine rotorcraft must be marked to indicate the position corresponding to each engine controlled; and
(4) The capacity of each tank must be marked on, or adjacent to, each selector controlling that tank.
(c) For accessory, auxiliary, and emergency controls--
(1) Each essential visual position indicator, such as those showing rotor pitch or landing gear position, must be marked so that each crewmember can determine at any time the position of the unit to which it relates: and
(2) Each emergency control must be colored red and marked as to method of operation.
[Revision note: Based on Sec. 7.737]
Sec. 29.863 Miscellaneous markings and placards.
(a) Baggage and cargo compartments, and ballast location. each baggage and cargo compartment, and each ballast location must have a placard stating all limitations on contents, including weight, that are necessary under the loading requirements.
(b) Seats. If the maximum allowable weight to be carried in a seat is less than 170 pounds, a placard stating such lesser weight must be permanently attached to the seat structure.
(c) Fuel and oil filler openings. The following must be marked on, or adjacent to, each appropriate filler cover:
(1) The word "fuel", the minimum fuel grade or designation fro the engines, and the usable fuel capacity of the tank.
(2) The word "oil" and the oil tank capacity.
(d) Emergency exit placards. Each placard and operating control for each emergency exit must be colored red. A placard must be located adjacent to each emergency exit control and must clearly indicate the location of that exit and its method of operation.
(e) Operating limitation placard. A placard must be provided in clear view of the pilot stating: "This (helicopter, gyrodyne, etc.) must be operated in compliance with the operating limitations specified in the FAA approved rotorcraft flight manual".
(f) Safety provisions. Safety provisions must be marked as follows:
(1) Each safety equipment control to be operated by the crew in emergency, such as flares and automatic liferaft releases, must be plainly marked as to its method of operation.
(2) Each location, such as a locker or compartment, that carries any fire extinguishing, signaling, or other life saving equipment must be marked accordingly.
(g) Tail rotor. Each tail rotor must be marked so that its disc is conspicuous under all normal ground conditions.
[Revision note: Based on Sec. 7.738]
ROTORCRAFT FLIGHT MANUAL
Sec. 29.873 General.
(a) A rotorcraft flight manual must be furnished with each rotorcraft.
(b) All portions of the manual listed in Secs. 29.875 through 29.879 that are appropriate to the rotorcraft must be verified and approved, and must be segregated, identified, and clearly distinguished from portions not approved.
(c) All information not specified in Secs. 29.875 through 29.879 that is required for safe operation because of unusual design, operating, or handling characteristics, must be furnished.
[Revision note: Based on Sec. 7.740]
Sec. 29.875 Operating limitations.
(a) Airspeed and rotor limitations. All information necessary for the making of airspeed and rotor limitations on, or adjacent to, their respective indicators must be furnished. In addition, the significance of each limitation and of the color coding must be explained.
(b) Powerplant limitations. Information must be furnished to explain all powerplant limitations, and to allow marking the instruments as required by Secs. 29.855 through 29.859.
(c) Weight and loading distribution. The weight and center of gravity limits required by Secs. 29.23 and 29.25 must be furnished, together with all items included in the empty weight in Sec. 29.29(a). If the variety of possible loading conditions warrants, instructions must be included to allow ready observance of the limitations.
(d) Flight crew. When a flight crew of more than one is required, the number and functions of the minimum flight crew determined in accordance with Sec. 29.833 must be described.
(e) Kinds of operation. Each kind of operation for which the rotorcraft and its equipment installations are approved must be listed.
(f) Limiting heights. Enough information must be furnished to allow compliance with Sec. 29.831.
(g) Unusable fuel. If the unusable fuel in any tank exceeds one gallon, or five percent of tank capacity, whichever is greater, warning must be provided to indicate to the flight personnel that the fuel remaining in that tank when the quantity indicator reads "zero" cannot be used safely in flight.
[Revision note: Based on Sec. 7.741]
Sec. 29.877 Operating procedures.
The portion of the manual containing operating procedures must have information concerning all normal and emergency procedures, and other pertinent information, necessary for safe operation, including all applicable procedures to be followed if an engine fails.
[Revision note: Based on Sec. 7.742]
Sec. 29.879 Performance information.
(a) Category A. For each category a rotorcraft, the rotorcraft flight manual must contain a summary of all performance data, including data necessary for the application of any operating rule of this chapter, together with descriptions of all conditions, such as airspeeds, under which these data were determined, and must contain--
(1) All indicated airspeeds corresponding with those determined for takeoff, and the procedures to be followed if the critical engine fails during takeoff;
(2) All airspeed calibrations;
(3) All techniques, associated airspeeds, and rates of descent for autorotative landings, and
(4) The maximum allowable wind for safe operation near the ground.
(b) Category B. For each category B rotorcraft, the rotorcraft flight manual must contain---
(1) The takeoff distance and the takeoff safety airspeed together with all pertinent information defining the flight path with respect to autorotative landing if an engine fails, including the calculated effects of altitude and temperature;
(2) The steady rates of climb and hovering ceiling together with the corresponding airspeeds and other pertinent information, including the calculated effects of altitude and temperature;
(3) The Ianding distance, appropriate glide airspeed, and kind of landing surface, together with any pertinent information that might affect this distance, including the calculated effects of altitude and temperature;
(4) The maximum safe wind for operation near the ground;
(5) All airspeed calibrations; and
(6) All additional performance data necessary for the application of any operating rule in this chapter.
[Revision notes: Based on Sec. 7.743]
Appendix A--Limit Drop Time
When an effective mean is used in showing compliance with Sec. 29.323, the following formula may be used in lieu of more rational computations.
where:
We = the effective weight to be used in the drop test (lbs.);
W = WM for main gear units (lbs.), equal to the static reaction on the particular unit with the rotorcraft in the most critical attitude. A rational method may be used in computing a main gear static reaction, taking into consideration the distance between the direction of the main wheel reaction and the rotorcraft center of gravity.
W = WN for nose gear units (lbs.), equal to the vertical component of the static reaction that
would exist at the nose wheel, assuming that the mass of the rotorcraft acts at the center
of gravity and exerts a force of 1.0g downward and 0.25g forward.
W = WT for tailwheel units (lbs.), equal to whichever of the following is critical:
(1) The static weight on the tailwheel with the rotorcraft resting on all wheels; or
(2) The vertical component of the ground reaction that would occur at the tailwheel, assuming that the mass of the rotorcraft acts at the center of gravity and exerts a force of 1g downward with the rotorcraft in the maximum nose-up attitude considered in the nose-up landing conditions.
h = specified free drop height (inches).
L = ratio of assumed rotor lift to the rotorcraft weight.
d = deflection under impact of the tire (at the approved inflation pressure) plus the vertical
component of the axle travels relative to the drop mass (inches).
n = limit inertia load factor.
nj =the load factor during impact developed on the mass used in the drop test (i.e., the
acceleration dv/dt in g's recorded in the drop test plus 1.0).
[Revision note: Combines note following Secs. 7.382(a) and 7.383]
PART 29
DISTRIBUTION TABLE
Present section | Revised section |
| 7.0 (1st sentence) | 29.1. |
| 7.0 (less 1st sentence) | Surplusage. |
| 7.1(a)(1) | Part 1 [New]. |
| 7.1(a)(2) | Surplusage. |
| 7.1(a) (less (1) and (2) ). | Part 1 [New]. |
| 7.1(b) (1) | Part 1 [New]. |
| 7.1(b)(2) | Part 1 [New]. |
| 7.1(b)(3) | Part 1 [New]. |
| 7.1 (b) (less (1)-(3)) | Part 1 [New]. |
| 7.1 (c) (1) | Part 1 [New]. |
| 7.1(c)(2) | Surplusage. |
| 7.1 (c)(3) | To be trfd. to Part 1[New]. |
| 7.1(c)(4) | Part 1 [New]. |
| 7.1(c) (5) | Surplusage. |
| 7.1(c) (7) | Surplusage. |
| 7.1(c) (less (1) - (7)) | Surplusage. |
| 7.1 (d) (1) - (d) (2) | Executed. |
| 7.1(d) (3) | Surplusage. |
| 7.1(d)(4)-(5) | Executed. |
| 7.1(d) (less (1)-(5) ) | To be trfd. to Part 1 [New]. |
| 7.1(e)(1) (1st sentence (less symbol "IAS")). | Part 1 [New]. |
| 7.1 (e)(1) (less 1st sentence). | Surplusage. |
| Symbol "IAS" | To be trfd. to Part 1 [New]. |
| 7.1(e)(2) | Part 1 [New]. |
| 7.1(e)(3) (less symbol "EAS"). | Part 1 [New]. |
| Symbol "EAS" | To be trfd. to Part 1 [New]. |
| 7.1(e)(4) (less symbol "TAS") | Part 1 [New]. |
| Symbol "TAS" | To be trfd. to Part 1 [New]. |
| 7.1(e) (less (5)-(7) ) | To be trfd. to Part 1 [New]. |
| 7.1 (e) (less (1) - (7)) | To be trfd. to Part 1 [New]. |
| 7.1(f) (1) - (6) | To be trfd. to Part 1 [New]. |
| 7.1(f) (less (1) - (6)) | Executed. |
| 7.1 (g) (1) - (3) | Part 1 [New]. |
| 7.1(g)(4) | To be trfd. to Part 1 [New]. |
| 7.1 (g) (5) | Part 1 [New]. |
| 7.1(g) (less (1)-(5) ) | To be trfd. to Part 1 [New]. |
| 7.1(h) (1)-(5) | To be trfd. to Part 1 [New]. |
| 7.1(h) (less (1)-(5) ) | 29.141. |
| 7.1(i) | Part 1 [New]. |
| 7.1(less(a) - (1) | Surplusage. |
| 7.10 - 7.19 | To be trfd. to proposed Part 21 [New]. |
| 7.20(a) and (b) (1st sentence). | 29.1. |
| 7.20(b) (less 1st sentence). | Surplusage. |
| 7.100 (less (a) - (c) ) | 29.21. |
| 7.100 (less (a) - (c) ) | Trfd. to proposed Part 21 [New]. |
| 7.101 | 29.23 |
| 7.102 | 29.25. |
| 7.103 | 29.27. |
| 7.104 | 29.29. |
| 7.105 | 29.31. |
| 7.110 (less note following). | 29.41 |
| Note following 7.110 | Not a rule. |
| 7.111 | 29.43. |
| 7.112 (a) | 29.47. |
| 7.112 (less (a)) | 29.45. |
| 7.113 | 29.47. |
| 7.114(a) | 29.47. |
| 7.114 (less (a)) | 29.49. |
| 7.115 (less (b) ) | 29.51. |
| 7.115 (b) (less (3) ) | 29.53. |
| 7.115 (b) (3) | 29.55. |
| 7.116 | 29.57. |
| 7.117 (less (a) ) | 29.58. |
| 7.117 (a) | 29.59. |
| 7.118 (a) and (b) | 29.59. |
| 7.118 (less (a) and (b)). | 29.61. |
| 7.120 | 29.69. |
| 7.121 | 29.71. |
| 7.122 | 29.73. |
| 7.123 | 29.75. |
| 7.130 | 29.85. |
| 7.131 | 29.87. |
| 7.132 | 29.89 |
| 7.140 (vibration aspect). | 29.99. |
| 7.140 (less vibration aspect). | 29.273. |
| 7.200 | 29.121. |
| 7.201 | 29.123. |
| 7.202 (less (c) ) | 29.125. |
| 7.202 (c) | Surplusage. |
| 7.203 | 29.125. |
| 7.204 | 29.127. |
| 7.210 | 29.137. |
| 7.211 | 29.139. |
| 7.212 | 29.141. |
| 7.213 | 29.143. |
| 7.214 | 29.145. |
| 7.220 | 29.155. |
| 7.221 | 29.157. |
| 7.222 | 29.159. |
| 7.223 | 29.161. |
| 7.224 | 29.163. |
| 7.225 | 29.165. |
| 7.226 | 29.165. |
| 7.230 | 29.175. |
| 7.231 | 29.177. |
| 7.232 | 29.179. |
| 7.233 | 29.181. |
| 7.234 | 29.183. |
| 7.235 | 29.185. |
| 7.236 | 29.187. |
| 7.240 | 29.193. |
| 7.245 | 29.203. |
| 7.246 | 29.205. |
| 7.250 | 29.217. |
| 7.251 | 29.219. |
| 7.252 | 29.221. |
| 7.260 | 29.229. |
| 7.261 (less note following). | 29.229. |
| Note following Sec. 7.261 | Not a rule |
| 7.300 | 29.251. |
| 7.301 | 29.253. |
| 7.302 | 29.255. |
| 7.303 | 29.257. |
| 7.304 | 29.259. |
| 7.305 | 29.261. |
| 7.306 | 29.263. |
| 7.307 (a) | 29.265. |
| 7.307 (b) | 29.267. |
| 7.307 (c) | 29.269. |
| 7.307 (less (a) - (c) ) | 29.271. |
| 7.310 | 29.281. |
| 7.311 | 29.283. |
| 7.312 | 29.285. |
| 7.313 | 29.287 |
| 7.320 | 29.297. |
| 7.321 | 29.299. |
| 7.322 | 29.301. |
| 7.323 | 29.303. |
| 7.324 | 29.305. |
| 7.325 | 29.307 |
| 7.326 | 29.309. |
| 7.327 | 29.311. |
| 7.328 | 29.313. |
| 7.330 | Executed. |
| 7.331 | Surplusage. |
| 7.332 (less note following (a) ). | 29.323. |
| Note following Sec. 7.332 (a) ). | Appendix A |
| 7.333 | Appendix A |
| 7.334 | 29.325. |
| 7.335 | 29.327. |
| 7.336 | 29.329. |
| 7.337 | 29.331. |
| 7.338 | 29.333. |
| 7.340 | 29.339. |
| 7.341 | 29.341. |
| 7.350 | 29.351. |
| 7.351 | 29.353 |
| 7.352 | 29.355. |
| 7.353 | 29.357. |
| 7.354 | 29.359. |
| 7.355 | 29.361. |
| 7.356 | 29.363. |
| 7.357 | 29.365. |
| 7.358 (less note following (c) ). | 29.367. |
| Note following Sec. 7.358 (c). | Not a rule. |
| 7.359 (1st 8 words) | 29.369. |
| 7.359 (less 1st 8 words) | Surplusage. |
| 7.380 | 29.377. |
| 7.381 | 29.379. |
| 7.382 (less note following (a) ). | 29.381 |
| Note following Sec. 7.382 (a). | Not a rule. |
| 7.383 | 29.383 |
| 7.384 | 29.385 |
| 7.385 | 29.387 |
| 7.390 | 29.396 |
| 7.391 | 29.397 |
| 7.392 | 29.399. |
| 7.400 | 29.421. |
| 7.401 | 29.423. |
| 7.402 | 29.425. |
| 7.403 | 29.435. |
| 7.404 | 29.437. |
| 7.405 (less sentences (4) and (5) of (a) (1) ). | 29.439. |
| 7.405 (a) (1) (sentence (4) ). | Transferred to Part 33 [New] |
| 7.405 (a) (1) (sentence (5) ). | Surplusage. |
| 7.406 | 29.441. |
| 7.407 | 29.443. |
| 7.408 | 29.445. |
| 7.410 | 29.453. |
| 7.411 | 29.455. |
| 7.413 | 29.457. |
| 7.416 | 29.459. |
| 7.417 | 29.461. |
| 7.418 | 29.463. |
| 7.420 | 29.473. |
| 7.421 | 29.475. |
| 7.422 | 29.477 |
| 7.423 | 29.479. |
| 7.424 | 29.481 |
| 7.425 | 29.483. |
| 7.426 | 29.485. |
| 7.427 | 29.487. |
| 7.428 | 29.489. |
| 7.430 (less 2d and 3d sentences of note following (a)). | 29.501. |
| (2d and 3d sentences of note following 7.430 (a)). | Not a rule. |
| 7.431 | 29.503. |
| 7.432 | 29.505. |
| 7.433 | Surplusage. |
| 7.434 | 29.507. |
| 7.435 | 29.509. |
| 7.436 | 29.511 |
| 7.437 | 29.513. |
| 7.440 | 29.523. |
| 7.441 | 29.525. |
| 7.442 | 29.527. |
| 7.443 | 29.529. |
| 7.444 | 29.531. |
| 7.445 | 29.533. |
| 7.446 | 29.535. |
| 7.447 | 29.537. |
| 7.448 | 29.539. |
| 7.450 | 29.551. |
| 7.451 (1st sentence) | 29.551. |
| 7.451 (less 1st sentence). | 29.553. |
| 7.452 | 29.555. |
| 7.453 | 29.557. |
| 7.454 | 29.559. |
| 7.455 | 29.561. |
| 7.460 | 29.571. |
| 7.461 | 29.573. |
| 7.462 | 29.575. |
| 7.463 | 29.577. |
| 7.464 | 29.579. |
| 7.465 | 29.581. |
| 7.466 | 29.583. |
| 7.467 | 29.585. |
| 7.470 | 29.601. |
| 7.471 | 29.603. |
| 7.472 | 29.605. |
| 7.473 | 29.607. |
| 7.474 | 29.609. |
| 7.475 | 29.611. |
| 7.476 | 29.613. |
| 7.477 (less note following). | 29.615. |
| Note following 7.477 | Not a rule. |
| 7.478 | 29.617. |
| 7.480 (less note following). | 29.631. |
| Note following 7.480 | Not a rule. |
| 7.481 | 29.633. |
| 7.482 | 29.635. |
| 7.483 | 29.637. |
| 7.484 | 29.639. |
| 7.485 | 29.641. |
| 7.486 | 29.643. |
| 7.487 | 29.645. |
| 7.489 | 29.647. |
| 7.600 (1st sentence) | 29.671. |
| 7.600 (less 1st sentence). | Not a rule. |
| 7.601 | 29.673. |
| 7.602-7.605 | 29.675. |
| 7.606 | 29.677. |
| 7.610 | Surplusage. |
| 7.611 | 29.691. |
| 7.612 | 29.693. |
PROPOSED RULE MAKING
PART 29 -- Continued
DISTRIBUTION TABLE --- continued
| Present section | Revised section |
| 7.613 | 29.695. |
| 7.620 | Surplusage. |
| 7.621 | 29.705. |
| 7.622 | 29.707. |
| 7.623 (less note following). | 29.709. |
| Note following 7.628 - | Not a rule. |
| 7.264 (less note following (e) ). | 29.711. |
| Note following 7.624 | Not a rule. |
| 7.625 (a) | 29.677. |
| 7.625 (less (a) ). | 29.713 |
| 7.626 | 29.715. |
| 7.627 | 29.717. |
| 7.630 | 29.727. |
| 7.631 | 29.729. |
| 7.632 | 29.731. |
| 7.633 | 29.733. |
| 7.634 | 29.735. |
| Figure 7-1 | 29.737. |
| Figure 7-2 | 29.739. |
| Figure 7-3 and note following. | 29.741. |
| 7.635 | 29.743. |
| 7.636 | 29.745. |
| 7.637 | 29.747. |
| Figure 7-4 | 29.747. |
| 7.640 | 29.761. |
| 7.641 | 29.763. |
| 7.642 | 29.763. |
| 7.643 | 29.765. |
| 7.644 (less note following (b) ). | 29.767. |
| Note following 7.644 (b). | Not a rule. |
| 7.645 | 29.769. |
| 7.646 (less note following). | 29.771. |
| Note following 7.646 | Not a rule. |
| 7.650 (less note following). | 29.781. |
| Note following 7.650 | Not a rule. |
| 7.651 | 29.783. |
| 7.652 | 29.785 |
| 7.653 (less note following (a) ). | 29.787. |
| Note following 7.653 (a). | Not a rule. |
| Following 7.653 -- | Not a rule. |
| 7.654 | 29.789. |
| 7.700 (a) | Surplusage. |
| 7.700 (less (a) ) | 29.811. |
| 7.710 | 29.821. |
| 7.711 | 29.823. |
| 7.712 | 29.825. |
| 7.713 (less intro. paragraph). | 29.827. |
| 7.713 (intro. paragraph). | Surplusage. |
| 7.714 | 29.829 |
| 7.715 | 29.831. |
| 7.716 | 29.832. |
| 7.717 | 29.833. |
| 7.718 | 29.835. |
| 7.719 | 29.837. |
| 7.730 | 29.847. |
| 7.731 | 29.849. |
| 7.732 | 29.851. |
| 7.733 | 29.853. |
| 7.734 | 29.855. |
| 7.735 | 29.857. |
| 7.736 (less last sentence). | 29.859. |
| Last sentence of Sec. 7.736. | Surplusage. |
| 7.737 | 29.861. |
| 7.738 | 29.863. |
| 7.740 | 29.873. |
| 7.741 | 29.875. |
| 7.742 | 29.877. |
| 7.743 | 29.879. |
| 7.744 | Surplusage. |
| Appendix A: | |
| SR 392C | Expired. |
| SR 392D | Expired. |
| SR 425C | Transferred to proposed Part 21 [New]. |
Footer Information
Issued in Washington, DC, on May 20, 1964.
N. E. Halaby,
Administrator.
[FR Doc. 64-5245 Filed 5-27-64; 8:45 am]
 Comments
Document History
Other Notice of Proposed Rulemaking Actions:
Not Applicable.
Final Rule Actions:
Final Rule. Docket No. 5084; Issued on 10/13/64.
|