Search Results - A (635 entries)

A.M. Peak Period: (See also P.M. Peak Period) The period in the morning when additional services are provided to handle higher passenger volumes. The period begins when normal, scheduled headways are reduced and ends when headways return to normal.  (FTA1)

A/C: Aircraft  (FAA8)

A/DACG: Arrival / Departure Airfield Control Group  (MTMC1)

A/G: Air - To - Ground  (FAA19)

A/I: Accident/Incident  (FRA4)

A3: Automatic Three Speed  (DOE6)

A4: Automatic Four Speed  (DOE6)

A5: Automatic Five Speed  (DOE6)

AAA: American Automobile Association  (FHWA11)

AAA: Automated Airlift Analysis  (MTMC1)

AAC: Advanced AERA Concepts  (FAA17)

AAC: Mike Monroney Aeronautical Center  (FAA7)

AADC: Approach and Departure Control  (FAA16)

AADT: Annual Average Daily Traffic  (FHWA8)

AAF: Army Airfield  (FAA17)

AAI: Arrival Aircraft Interval  (FAA4)

AAIA: Airport and Airway Improvement Act  (OST3)

AAL: American Airlines  (FAA18)

AALPS: Automated Air Load Planning System  (MTMC1)

AAMA: American Automobile Manufacturers Association  (BTS8)

AAMVA: American Association of Motor Vehicle Administrators  (FHWA10)   (NHTSA6)

AAN: Air Ambulance Network  (MTMC1)

AAP: Advanced Automation  (FAA17)

AAPA: American Association of Port Authorities  (MARAD4)

AAR: Airport Acceptance Rate  (FAA4)   (FAA8)

AAR: Association of American Railroads  (BTS2)   (MTMC1)   (RSPA1)

AAS: Advanced Automation System  (FAA17)   (FAA7)   (FAA8)

AAS: Airport Advisory Service  (FAA2)

AASHTO: American Association of State Highway and Transportation Officials  (FHWA7)   (FHWA8)

AAWDT: Annual Average Weekday Traffic  (TRB1)

ABA: American Bus Association  (ENO1)

Abaft: A point beyond the midpoint of a ship's length.  (MARAD2)

Abandoned Runway: Intact but not maintained or intended for use runway.  (DOI3)

Abbreviated Injury Scale: An integer scale developed by the Association for the Advancement of Automotive Medicine to rate the severity of individual injuries.  (NHTSA2)

Abbreviated Instrument Flight Rules (IFR) Flight Plans: An authorization by Air Traffic Control (ATC) requiring pilots to submit only that information needed for the purpose of ATC. It includes only a small portion of the usual Instrument Flight Rules (IFR) flight plan information. In certain instances, this may be only aircraft identification, location, and pilot request. Other information may be requested if needed by ATC for separation/control purposes. It is frequently used by aircraft which are airborne and desire an instrument approach or by aircraft which are on the ground and desire a climb to Visual Flight Rule (VFR)-on-top.  (FAA4)

Abeam: An aircraft is "abeam" a fix, point, or object when that fix, point, or object is approximately 90 degrees to the right or left of the aircraft track. Abeam indicates a general position rather than a precise point.  (FAA4)

Abort: To terminate a preplanned aircraft maneuver; (e.g., an aborted takeoff).  (FAA4)

ABQ: Albuquerque International Airport  (FAA11)

ABS: American Bureau of Shipping  (MARAD4)

ABS: Antilock Braking System  (NHTSA5)

ABS: Automatic Block Signal  (TRB1)

Absolute Block: A block in which no train is permitted to enter while it is occupied by another train.  (49CFR218)

ABYC: American Boat and Yacht Council  (USCG1)

AC: Advisory Circular  (FAA19)   (FAA12)

AC: Airframe Change  (MTMC1)

AC: Asphalt Concrete  (FHWA7)

AC: Alcohol Concentration  (49CFR383)

AC: Aircraft Commander  (MTMC1)

AC: Air Controller  (MTMC1)

AC: Aircraft  (MTMC1)

ACAIS: Air Carrier Activity Information System  (BTS7)   (FAA11)

ACARS: Automatic Communications Addressing and Reporting System  (FAA17)

ACAS: Airborne Collision Avoidance System  (FAA7)

ACC: Air Center Commander  (MTMC1)

ACC: Area Control Center  (FAA4)

ACC: Aircraft Commander  (MTMC1)

ACC/INC: Accident/Incident  (FRA4)

ACCC: Area Control Computer Complex  (FAA17)   (FAA8)

Accelerate Stop Distance Available: The runway plus stopway length declared available and suitable for the acceleration and deceleration of an airplane aborting a takeoff.  (FAA4)   (FAA12)

Acceleration Power: Measured in kilowatts. Pulse power obtainable from a battery used to accelerate a vehicle. This is based on a constant current pulse for 30 seconds at no less than 2/3 of the maximum open-circuit-voltage, at 80% depth-of-discharge relative to the battery's rated capacity and at 20 degrees Celsius ambient temperature.  (DOE6)

Access Restrictions Road Gate: Constraints on use.  (DOI3)

Access Rights: This element identifies who has acquired legal access rights over a road segment.  (DOI2)

Accessible Stations: A public transportation passenger facility which provides ready access, is useable, and does not have physical barriers that prohibit and/or restrict access by individuals with disabilities, including individuals who use wheelchairs.  (FTA1)

Accessible Vehicles: Public transportation revenue vehicles which do not restrict access, are usable, and provide allocated space and/or priority seating for individuals who use wheelchairs.  (FTA1)

Accessory or Auxiliary Equipment: A particular item of equipment added to a vehicle to aid or contribute to the vehicle's operation and/or mission.  (GSA2)

Accident: See also Casualty, Collision, Crash, Derailment, Event, Fatality, Incident, Injury, Jackknife, Rollover, Third Party, Truck Crash, Type of Occurrence.

Accident: Includes continuous or repeated exposure to the same conditions resulting in public liability which the insured neither expected nor intended.  (49CFR387)

Accident: An occurrence involving a commercial motor vehicle operating on a public road which results in one of the following: a fatality; bodily injury to a person, who as a result of the injury, immediately receives medical treatment away from the scene of the accident; or one or more motor vehicles incurring disabling damage as a result of the accident, requiring the vehicle to be transported away from the scene by a tow truck or other vehicle. It does not include: an occurrence involving only boarding and alighting from a stationary motor vehicle; an occurrence involving only the loading or unloading of cargo; or an occurrence in the course of the operation of a passenger car or a multipurpose passenger vehicle, as defined in 49 CFR 571.3, by a motor carrier and is not transporting passengers for hire or hazardous materials of a type and quantity that require the motor vehicle to be marked or placarded in accordance with 49 CFR 177.823.  (49CFR390)

Accident: 1) An event that involves the release of gas from a pipeline or of liquefied natural gas or gas from an LNG facility resulting in a death, or personal injury necessitating in-patient hospitalization; or estimated property damage, including cost of gas lost, of the operator or others, or both, of $50,000 or more; 2) an event that results in an emergency shutdown of an LNG facility; 3) an event that is significant, in the judgment of the operator, even though it did not meet the criteria of 1) or 2).  (AGA1)

Accident: An incident involving a moving vehicle. Includes collisions with a vehicle, object, or person (except suicides) and derailment/left roadway.  (FTA2)

Accident: Occurrence in a sequence of events that produces unintended injury, death or property damage. Accident refers to the event, not the result of the event.  (NSC1)

Accident Classes: Used to categorize commercial vehicle accidents according to accident severity (i.e., fatal accidents, injury accidents, and property damage accidents).  (FHWA4)

Accident Consequences: The physical results of motor vehicle accidents. Consequences include fatalities, injuries, and property damage.  (FHWA2)   (FHWA4)

Accident Severity: Measures the seriousness of an accident according to the type and quantity of the accident's consequences. Fatalities are more severe than injuries, and injuries are more severe than property damage.  (FHWA2)   (FHWA4)

Accident Type: An accident type is classified as either "collision" or "non-collision."  (FHWA2)   (FHWA4)

Accident/Incident: 1) Any impact between railroad on-track equipment and an automobile, bus, truck, motorcycle, bicycle, farm vehicle or pedestrian at a rail-highway grade crossing; 2) Any collision, derailment, fire, explosion, act of God, or other event involving operation of railroad on-track equipment (standing or moving) that results in more than $6,300 in damages to railroad on-track equipment, signals, track, track structures, and road-bed; 3) Any event arising from the operation of a railroad which results in: i) Death of one or more persons; ii) Injury to one or more persons, other than railroad employees, that requires medical treatment; iii) Injury to one or more employees that requires medical treatment or results in restriction of work or motion for one or more days, one or more lost work days, transfer to another job, termination of employment, or loss of consciousness; or iv) Occupational illness of a railroad employee as diagnosed by a physician.  (49CFR225)

Accounting Changes Income (Loss): The difference between the amount of retained earnings at the beginning of the period in which a change in accounting has occurred and the amount of retained earnings that would have been reported, net of applicable taxes, at that date if the new accounting had been applied retroactively for all applicable periods.  (BTS4)

ACD: Engineering, Research and Development Service  (FAA17)

ACDO: Air Carrier District Office  (FAA4)

ACE: Airport Capacity Enhancement  (FAA17)

ACF: Area Control Facility  (FAA17)   (FAA19)   (FAA8)

ACHP: Advisory Committee On Highway Policy  (MTMC1)

ACIP: Airport Capital Improvement Program  (OST3)

Acknowledging Device: A manually operated electric switch or pneumatic valve by means of which, on a locomotive equipped with an automatic train stop or train control device, an automatic brake application can be forestalled, or by means of which, on a locomotive equipped with an automatic cab signal device, the sounding of the cab indicator can be silenced.  (49CFR236)

Acknowledging Time: As applied to an intermittent automatic train stop system, a predetermined time within which an automatic brake application may be forestalled by means of the acknowledging device.  (49CFR236)

Acknowledgment Circuit: A circuit consisting of wire or other conducting material installed between the track rails at each signal in territory where an automatic train stop system or cab signal system of the continuous inductive type with 2-indication cab signals is in service, to enforce acknowledgement by the engineman at each signal displaying an aspect requiring a stop.  (49CFR236)

ACLS: Automatic Carrier Landing System  (FAA4)

ACLT: Actual Calculated Landing Time  (FAA4)

Acrobatic Flight: An intentional maneuver involving an abrupt change in an aircraft's attitude, an abnormal attitude, or abnormal acceleration not necessary for normal flight.  (FAA4)

ACSEP: Aircraft Certification Systems Evaluation Program  (FAA7)

ACSSP: Air Carrier Standard Security Programs  (FAA1)

Active Aircraft: All legally registered civil aircraft which flew one or more hours.  (FAA2)   (FAA6)   (FAA9)

Active Vehicle: Transit passenger vehicles licensed, where required, and maintained for regular use, including spares and vehicles out of service for maintenance purposes, but excluding vehicles in "dead" storage, leased to other operators, in energy contingency reserve status, permanently not usable for transit service, and new vehicles not yet outfitted for active service.  (APTA1)

Active Vehicles in Fleet: The vehicles in the year end fleet that are available to operate in revenue service, including vehicles temporarily out of service for routine maintenance and minor repairs.  (FTA1)

ACTS: American Coalition for Traffic Safety, Inc.  (MM)

Actual Calculated Landing Time (ACLT): A flight's frozen calculated landing time. An actual time determined at freeze calculated landing time (FCLT) or meter list display interval (MLDI) for the adapted vertex for each arrival aircraft based upon runway configuration, airport acceptance rate, airport arrival delay period, and other metered arrival aircraft. This time is either the vertex time of arrival (VTA) of the aircraft or the tentative calculated landing time (TCLT)/actual calculated landing time (ACLT) of the previous aircraft plus the arrival aircraft interval (AAI), whichever is later. This time will not be updated in response to the aircraft's progress.  (FAA4)

Actual Service: Total service operated during each time period. Actual service excludes missed trips and service interruptions (e.g., strikes, emergency shutdowns), but includes deadheading. Actual service is measured by vehicles in service, in miles and/or hours.  (FTA1)

Actual Severity: On scene evaluation of the degree of danger that existed. An "after-the-fact" evaluation by the reporting unit.  (USCG3)

Actual Vehicle Miles/Hours: The miles/hours a vehicle travels while in revenue service (actual vehicle revenue miles/hours) plus deadhead miles/hours. For rail vehicles, vehicle miles/hours refer to passenger car miles/hours. Actual vehicle miles/hours exclude miles and hours for charter services, school bus service, operator training and maintenance testing.  (FTA1)

Ad Valorem: A charge levied on persons or organizations based on the value of transaction. It is normally a given percentage of the price at the retail or manufacturing stage and is a common form of sales tax; e.g. Federal excise tax on new trucks and trailers.  (ATA2)

Ad Valorem: 1) A freight rate set at a certain percentage of the value of an article; 2) A set percentage of the value of dutiable goods determined by the price at the port of shipment and calculated for duty assessment.  (TNDOT1)

ADA: Americans With Disabilities Act  (49CFR37)   (BTS8)   (OFR1)

ADA: Aviation Data and Analysis System  (BTS7)

ADAP: Airport Development Aid Program  (FAA19)

ADAS: AWOS Data Acquisition System  (FAA19)

Additional Capital Invested: The difference between the price at which capital stock is sold and the par or stated value of the stock, gains or losses arising from the reacquisition and the resale or retirement of each class and series of capital stock, donations, the excess of retained earnings capitalized over par or stated value of capital stock issued, adjustments in capital resulting from reorganization or recapitalization, proceeds attributable to detachable stock purchase warrants related to debt issues, and contributions to the business enterprise by individual proprietors or partners.  (BTS4)

Additional Services: Advisory information provided by Air Traffic Control (ATC) which includes but is not limited to the following: 1) Traffic advisories. 2) Vectors, when requested by the pilot, to assist aircraft receiving traffic advisories to avoid observed traffic. 3) Altitude deviation information of 300 feet or more from an assigned altitude as observed on a verified (reading correctly) automatic altitude readout (Mode C). 4) Advisories that traffic is no longer a factor. 5) Weather and chaff information. 6) Weather assistance. 7) Bird activity information. 8) Holding pattern surveillance. Additional services are provided to the extent possible contingent only upon the controller's capability to fit them into the performance of higher priority duties and on the basis of limitations of the radar, volume of traffic, frequency congestion, and controller workload. The controller has complete discretion for determining if he is able to provide or continue to provide a service in a particular case. The controller's reason not to provide or continue to provide a service in a particular case is not subject to question by the pilot and need not be made known to him.  (FAA4)

Additional Vehicle: A vehicle added to the inventory of a Fleet Management Center to fill a new program or to expand on an existing program of a participating agency.  (GSA2)

ADDM: Automated Documentation Development and Maintenance  (FAA19)

ADF: Automatic Direction Finder  (FAA16)   (FAA4)   (FAA6)

ADI: Aircraft De - Ice and Inhibitor  (MTMC1)

ADIS: Advanced Driver Information System  (TXDOT)

ADIZ: Air Defense Identification Zone  (FAA3)   (FAA4)   (FAA8)

Adjustable Speed Drives: Drives that save energy by ensuring the motor's speed is properly matched to the load placed on the motor. Terms used to describe this category include polyphase motors, motor oversizing, and motor rewinding.  (DOE5)

ADL: Aeronautical Data - Link  (FAA19)

ADLY: Arrival Delay  (FAA4)

Administrative Class V Road: An administrative access road which consists of all public roads intended for access to administrative developments or structures such as offices, employee quarters, or utility areas.  (DOI1)

Administrative Class VI Road: A restricted road normally closed to the public, including patrol roads, truck trails, and other similar roads.  (DOI1)

Administrative Road: Consists of all public and non-public roads intended to be used principally for administrative purposes. It includes roads servicing employee residential areas, maintenance areas and other administrative developments, as well as restricted patrol roads, truck trails, and similar service roads.  (DOI1)

ADP: Automated Data Processing  (FAA19)

ADR: Automated Demand Resolution  (FAA17)

ADS: Automatic Dependent Surveillance  (FAA17)   (FAA7)   (FAA19)

ADSIM: Airfield Delay Simulation Model  (FAA17)

ADT: Average Daily Traffic  (FHWA1)

ADTN: Administrative Data Transmission Network  (FAA19)

ADVANCE: Advanced Driver And Vehicle Advisory Navigation Concept  (FHWAII)

Advances from Associated Companies: Net amounts due associated companies and nontransport divisions for notes, loans and advances that are not settled currently.  (BTS4)

Adverse Weather: The weather conditions considered by the operator in identifying the response systems and equipment to be deployed in accordance with a response plan, including wave height, ice, temperature, visibility, and currents within the inland or Coastal Response Zone (defined in the National Contingency Plan (40 CFR 300)) in which those systems or equipment are intended to function.  (49CFR194)

Advise Intentions: Tell me what you plan to do.  (FAA4)

Advising Bank: A domestic bank which handles letters of credit for a foreign bank by notifying the exporter that the credit has been opened in his favor, fully informing him of the conditions and terms without responsibility on the part of the bank.  (TNDOT1)

Advisory Frequency: The appropriate frequency to be used for Airport Advisory Service.  (FAA4)

Advisory Service: Advice and information provided by a facility to assist pilots in the safe conduct of flight and aircraft movement.  (FAA4)

AEG: Aircraft Evaluation Group  (FAA3)

AERA: Automated En Route Air Traffic Control  (FAA17)   (FAA7)   (FAA19)   (FAA8)

Aerial Application: Any use of an aircraft for work purposes which concerns the production of foods, fibers, and health control in which the aircraft is used in lieu of farm implements or ground vehicles for the particular task accomplished. This includes fire fighting operations, the distribution of chemicals or seeds in agriculture, reforestation, or insect control.  (FAA2)   (FAA9)

Aerial Application Flying: The operation of aircraft for the purpose of dispensing any substance for plant nourishment, soil treatment, propagation of plant life, pest control, or fire control, including flying to and from the application site.  (NTSB2)

Aerial Observation: Any use of an aircraft for aerial mapping and photography, survey, patrol, fish spotting, search and rescue, hunting, highway traffic advisory, or sightseeing; not included under Part 135.  (FAA2)   (FAA9)

Aerial Refueling: A procedure used by the military to transfer fuel from one aircraft to another during flight.  (FAA4)

Aerial Tramway: An electric system of aerial cables with suspended unpowered passenger vehicles. The vehicles are propelled by separate cables attached to the vehicle suspension system and powered by engines or motors at a central location not on board the vehicle.  (APTA1)

Aerial Tramway: Unpowered passenger vehicles suspended from a system of aerial cables and propelled by separate cables attached to the vehicle suspension system. The cable system is powered by engines or motors at a central location not on board the vehicle.  (FTA1)

Aerodrome: (See also Airport, Heliport) A defined area on land or water (including any buildings, installations, and equipment) intended to be used either wholly or in part for the arrival, departure, and movement of aircraft. Aerodromes may include airports, heliports, and other landing areas.  (FAA4)   (FAA8)

Aerodrome Beacon: Aeronautical beacon used to indicate the location of an aerodrome from the air.  (FAA4)

Aerodrome Control Tower: A unit established to provide air traffic control service to aerodrome traffic.  (FAA4)

Aerodrome Elevation: The elevation of the highest point of the landing area.  (FAA4)

Aerodrome Traffic Circuit: The specified path to be flown by aircraft operating in the vicinity of an aerodrome.  (FAA4)

Aerodynamic Coefficient: Non-dimensional coefficients for aerodynamic forces and moments.  (14CFR1)

Aeronautical Beacon: A visual Navigation Aid (NAVAID) displaying flashes of white and/or colored light to indicate the location of an airport, a heliport, a landmark, a certain point of a federal airway in mountainous terrain, or an obstruction.  (FAA4)

Aeronautical Chart: A map used in air navigation containing all or part of the following topographic features: hazards and obstructions, navigation aids, navigation routes, designated airspace, and airports.  (FAA4)

Aeronautical Information Manual (AIM): A primary Federal Aviation Administration (FAA) publication whose purpose is to instruct airmen about operating in the National Airspace System of the U.S. It provides basic flight information, Air Traffic Control (ATC) procedures and general instructional information concerning health, medical facts, factors affecting flight safety, accident and hazard reporting, and types of aeronautical charts and their use.  (FAA4)

Aeronautics: Science that treats of the operation of aircraft, also the art or science of operating aircraft.  (AIA1)

AEX: Automated Execution  (FAA17)

AF: Airway Facilities  (FAA17)   (FAA7)   (FAA19)

AFB: Air Force Base  (FAA17)   (FAA19)

AFC: Automatic Fare Collection  (TRB1)

AFD: Airport Facility Directory  (FAA16)

AFI: African India Ocean Region  (USTTA1)

AFSS: Automated Flight Service Station  (FAA19)   (FAA8)   (FAA13)

AFV: Alternative-Fuel Vehicles  (BTS2)

AFV: Armored Family of Vehicles  (MTMC1)

AFZ: Auto-Free Zone  (TRB1)

AGA: American Gas Association  (AGA1)

AGFS: Aviation Gridded Forecast System  (FAA17)

Aggregate Ratio: See Estimate Ratio, Mean and Ratio Estimate.

Agitator Body: Truck body designed and equipped to mix concrete in transit.  (ATA1)

AGL: Above Ground Level  (FAA17)

Agricultural Commodity Trailer: A trailer that is designed to transport bulk agricultural commodities in off-road harvesting sites and to a processing plant or storage location, as evidenced by skeletal construction that accommodates harvest containers, a maximum length of 28 feet, and an arrangement of air control lines and reservoirs that minimizes damage in field operations.  (49CFR393)

AGT: Automated Guideway Transit  (TRB1)

AHAR: Advanced Highway Advisory Radio  (FHWA15)

AHIP: Army Helicopter Improvement Program  (MTMC1)

AHS: Automated Highway Systems  (FHWA14)

AIAA: Aerospace Industries Association of America, Inc.  (AIA1)

AICC: Automated Intelligent Cruise Control  (FHWAII)

AIFSS: Automated International Flight Service Station  (FAA13)

AIG: Airbus Industries Group  (FAA14)

AIM: Aeronautical Information Manual  (FAA4)

AIMS: American Institute of Merchant Shipping  (ENO1)

AIP: Aeronautical Information Publication  (FAA4)

AIP: Airport Improvement Program  (FAA17)   (FAA7)   (FAA19)   (FAA11)

Air Brake: A brake in which the mechanism is actuated by manipulation of air pressure. The term is often used to describe brakes that employ air under pressure above atmospheric, in contrast to vacuum brakes, which employ pressure below atmospheric.  (TRB1)

Air Cargo: Cargo is freight and mail loaded and unloaded (arriving and departing) at the airport. Freight is any property carried on an aircraft other than mail, stores and baggage. Mail comprises closed bags handed over by the postal service, whatever their contents may be. Does not include passenger baggage and trucked freight.  (ACI1)

Air Cargo: Total volume of freight, mail and express traffic transported by air. Includes the following: Freight and Express-commodities of all kinds, includes small package counter services, express services and priority reserved freight; U.S. Mail-all classes of mail transported for the U.S. Postal Service.  (ATAB1)

Air Carrier: A person who undertakes directly by lease, or other arrangement, to engage in air transportation.  (14CFR1)

Air Carrier: Commercial system of air transportation, consisting of domestic and international scheduled and charter service.  (AIA1)

Air Carrier: Commercial system of air transportation consisting of certificated air carriers, air taxis (including commuters), supplemental air carriers, commercial operators of large aircraft, and air travel clubs.  (DOE6)   (FAA6)

Air Carrier: As defined in the Federal Aviation Act of 1958, any citizen of the United States who undertakes, whether directly or indirectly, or by lease or any other arrangement, to engage in air transportation.  (FAA1)

Air Carrier: An air carrier holding a Certificate of Public Convenience and Necessity issued by the Department of Transportation to conduct scheduled services over specified routes and a limited amount of nonscheduled operations.  (FAA13)

Air Carrier Activity Information System (ACAIS): Database of revenue passenger enplanement and all-cargo landing data used in the distribution of AIP (Airport Improvement Program) entitlement funds.  (FAA11)

Air Carrier Operations: Arrivals and departures of air carriers certificated in accordance with Federal Aviation Regulations (FAR) Parts 121 and 127.  (FAA14)

Air Commerce: Interstate, overseas, or foreign air commerce or the transportation of mail by aircraft or any operation or navigation of aircraft within the limits of any Federal airway or any operation or navigation of aircraft which directly affects, or which may endanger safety in, interstate, overseas, or foreign air commerce.  (14CFR1)

Air Courier Service: Establishments primarily engaged in furnishing air delivery of individually addressed letters, parcels, and packages (generally under 100 pounds), except by the U.S. Postal service. While these establishments deliver letters, parcels, and packages by air, the initial pick-up and the final delivery are often made by other modes of transportation, such as by truck, bicycle, or motorcycle. Separate establishments of air courier companies engaged in providing pick-up and delivery only, drop-off points; or distribution centers are all classified in this industry.  (BOC1)

Air Defense Identification Zone (ADIZ): The area of airspace over land or water, extending upward from the surface, within which the ready identification, location, and control of aircraft are required in the interest of national security. Air Defense Identification Zone (ADIZ) locations and operating and flight plan requirements for civil aircraft operations are specified in FAR Part 99.  (FAA4)

Air Express (Reserved Priority Air Freight): Freight shipments which are shipped on a guaranteed served flight basis at a premium rate, not to be confused with small package service which is restricted to shipments of 50 pounds or less.  (BTS5)

Air Mode: See Aviation Mode.

Air Navigation Facility: (See also Navigational Aid) Any facility used in, available for use in, or designed for use in, aid of air navigation, including landing areas, lights, any apparatus or equipment for disseminating weather information, for signaling, for radio-directional finding, or for radio or other electrical communication, and any other structure or mechanism having a similar purpose for guiding or controlling flight in the air or the landing and take-off of aircraft.  (FAA4)

Air Navigation Hazard: An object which, as a result of an aeronautical study, the Federal Aviation Administration (FAA) determines will have an adverse effect upon the safe and efficient use of navigable airspace by aircraft, operation of air navigation facilities, or existing or potential airport capacity.  (FAA12)

Air Operator: A person or organization authorized to operate aircraft or aviation facilities under FAR Parts 91, 121, 125, 127, 129, 133, 135, or 137.  (FAA3)

Air Route Surveillance Radar (ARSR): Air Route Traffic Control Center (ARTCC) radar used primarily to detect and display an aircraft's position while en route between terminal areas. The ARSR enables controllers to provide radar air traffic control service when aircraft are within the ARSR coverage. In some instances, ARSR may enable an Air Route Traffic Control Center (ARTCC) to provide terminal radar services similar to but usually more limited than those provided by a radar approach control.  (FAA4)

Air Route Traffic Control Center (ARTCC): A facility established to provide air traffic control service to aircraft operating on an Instrument Flight Rules (IFR) flight plan within controlled airspace and principally during the en route phase of flight. When equipment capabilities and controller workload permit, certain advisory and assistance services may be provided to Visual Flight Rules (VFR) aircraft.  (FAA2)   (FAA13)   (FAA14)

Air Taxi: A classification of air carriers, which transports, in accordance with Federal Aviation Regulations (FAR) Part 135, persons, property, and mail using small aircraft (under 30 seats or a maximum payload capacity of 7,500).  (FAA2)

Air Taxi: Used to describe a helicopter/Vertical Take Off and Landing (VTOL) aircraft movement conducted above the surface but normally not above 100 feet above ground level. The aircraft may proceed either via hover taxi or flight at speeds more than 20 knots. The pilot is solely responsible for selecting a safe airspeed/altitude for the operation being conducted.  (FAA4)

Air Taxi: A classification of air carriers which directly engage in the air transportation of persons, property, mail, or in any combination of such transportation and which do not directly or indirectly use large aircraft (over 30 seats or a maximum payload capacity of more than 7,500 pounds) and do not hold a Certificate of Public Convenience and Necessity or economic authority issued by the Department of Transportation.  (FAA6)

Air Taxi: An air taxi operator which: 1) Performs at least five round trips per week between two or more points and publishes flight schedules which specify the times, days of the week and places between which such flights are performed; or 2) Transports mail by air pursuant to a current contract with the U.S. Postal Service.  (FAA13)

Air Taxi: An air carrier certificated in accordance with FAR Part 135 and authorized to provide, on demand, public transportation of persons and property by aircraft. Generally operates small aircraft "for hire" for specific trips.  (FAA14)

Air Taxi Survey: Federal Aviation Administration (FAA) form 1800-31, sent to carriers for reporting of Air Taxi Commercial Operator (ATCO) activity.  (FAA11)

Air Taxi/Commercial Operator (ATCO): Commercial air carrier operating on-demand air taxi services on aircraft. Certificated in accordance with Federal Aviation Regulation Part 135.  (FAA11)

Air Traffic: Aircraft operating in the air or on an airport surface, exclusive of loading ramps and parking areas. Also referred to as airport traffic.  (14CFR1)   (FAA4)   (FAA14)

Air Traffic Clearance: An authorization by air traffic control, for the purpose of preventing collision between known aircraft, for an aircraft to proceed under specified traffic conditions within controlled airspace.  (14CFR1)   (FAA4)

Air Traffic Command and Control Center (ATCCC): An Air Traffic Operations service facility consisting of four operational units; 1) Central Flow Control Function (CFCF)-Responsible for coordination and approval of all major inter-center flow control restrictions on a system basis in order to obtain maximum utilization of the airspace. 2) Responsible for coordinating, planning,and approving special user requirements under the Altitude Reservation concept. 3) Airport Reservation Office (ARO)-Responsible for approving Instrument Flight Rules (IFR) flights at designated high density traffic airports (John F. Kennedy, LaGuardia, O'Hare and Washington National) during specified hours. 4) Air Traffic Control (ATC) Contingency Command Post-A facility that enables the Federal Aviation Administration (FAA) to manage the ATC system when a significant portion of the system's capabilities have been lost or are threatened.  (FAA8)

Air Traffic Control (ATC): Service operated by an appropriate authority to promote the safe, orderly, and expeditious flow of air traffic.  (FAA2)

Air Traffic Control (ATC): The safety separation process to prevent collisions between aircraft and collisions with obstructions while expediting and maintaining an orderly flow of air traffic: an element of the air traffic management process.  (FAA7)

Air Traffic Control (ATC) Clearance: Authorization for an aircraft to proceed under conditions specified by an air traffic control unit.  (FAA4)

Air Traffic Control Facility: A facility which provides air traffic control services located in the U.S., its possessions and territories, and in foreign countries especially established by international agreement.  (FAA2)

Air Traffic Control Service: A service provided for the purpose of 1) Preventing collisions between aircraft and on the maneuvering area between aircraft and obstructions and 2) Expediting and maintaining an orderly flow of air traffic.  (FAA4)

Air Traffic Control Specialist: (See also Controller; Final Controller) A person authorized to provide air traffic control service.  (FAA4)

Air Traffic Hub: Air traffic hubs are not airports; they are the cities and Standard Metropolitan Statistical Areas requiring aviation services. The hubs fall into four classes as determined by each community's percentage of the total enplaned passengers all services and all operations U.S. certificated air carriers in the 50 states, the District of Columbia, and other U.S. areas designated by the Federal Aviation Administration. Large: a community enplaning 1.00% or more of the total enplaned passengers; Medium: 0.25% to 0.99%; Small: 0.05% to 0.24%; Nonhub: Less than 0.05%.  (FAA2)   (FAA10)   (FAA13)   (FAA14)   (FAA15)

Air Traffic Liabilities: The value of transportation sold, but not used or refunded (i.e., liabilities to passengers or liabilities to others. These include payables to other airlines for portions of interline passenger trips amounts the ticketing carrier owes the performing carrier. Also included are amounts the ticketing carrier owes to passengers prior to flights, which remain unearned revenue until air transportation is provided).  (BTS4)

Air Traffic Management (ATM): The process used to ensure the safe, efficient, and expeditious movement of aircraft during all phases of operations. Air traffic management consists of air traffic control and traffic flow management.  (FAA7)

Air Traffic Service: A generic term meaning: 1) Flight Information Service; 2) Alerting Service; 3) Air Traffic Advisory Service; 4) Air Traffic Control Service, Area Control Service, Approach Control Service, or Airport Control Service.  (FAA4)

Air Transport Movements: Landing and take-off of an aircraft operating a scheduled or non-scheduled service.  (ACI1)

Air Transportation: Interstate, overseas, or foreign air transportation or the transportation of mail by aircraft.  (14CFR1)

Air Transportation: Includes establishments that provide domestic and international passenger and freight services, and establishments that operate airports and provide terminal facilities. Also included are flying services such as crop dusting and aerial photography.  (BEA1)

Air Travel Club: An operator certificated in accordance with FAR Part 123 to engage in the carriage of members who qualify for that carriage by payment of an assessment, dues, membership fees, or other similar remittance.  (FAA14)

Air Waybill: A bill of lading which covers both domestic and international flights transporting goods to a specified destination. Technically, it is a non-negotiable instrument of air transport which serves as a receipt for the shipper, indicating that the carrier has accepted the goods listed therein and obligates itself to carry the consignment to the airport of destination according to specified conditions.  (USTTA1)

Airbus Industries Group (AIG): A supernational management organization responsible for design, development, manufacture, marketing, sales and support of selected commercial aircraft.  (USTTA1)

Aircraft: See also Airframe, Airplane, Airship.

Aircraft: All airborne vehicles supported either by buoyancy or by dynamic action. Used in a restricted sense to mean an airplane-any winged aircraft, including helicopters but excluding gliders and guided missiles.  (AIA1)

Aircraft: Device/s that are used or intended to be used for flight in the air. When used in air traffic control terminology may include the flight crew.  (FAA8)

Aircraft Accident: Occurrence incident to flight in which, "as a result of the operation of an aircraft, any person (occupant or nonoccupant) receives fatal or serious injury or any aircraft receives substantial damage." The definition of substantial damage is 1) substantial damage means damage or failure which adversely affects the structural strength, performance, or flight characteristics of the aircraft, and would normally require major repair or replacement of the affected component; 2) engine failure, damage limited to an engine, bent fairings or cowling, dented skin, small punctured holes in the skin or fabric, ground damage to rotor or propeller blades, damage to landing gear, wheels, tires, flaps, engine accessories, brakes, or wingtips are not considered "substantial damage."  (NTSB1)

Aircraft Agreement (Agreement On Trade In Civil Aircraft): Negotiated in the Tokyo Round of the Multilateral Trade Negotiations, and implemented January 1, 1980, providing for elimination of tariff and non-tariff trade barriers in the civil aircraft sector.  (AIA1)

Aircraft and Traffic Servicing Expenses: Compensation of ground personnel, in-flight expenses for handling and protecting all nonpassenger traffic including passenger baggage, and other expenses incurred on the ground to 1) Protect and control the in-flight movement of aircraft, 2) Schedule and prepare aircraft operational crews for flight assignment, 3) Handle and service aircraft while in line operation, and 4) Service and handle traffic on the ground after issuance of documents establishing the air carrier's responsibility to provide air transportation.  (BTS4)

Aircraft Approach Category: A grouping of aircraft based on 1.3 times their stall speed in landing configuration at maximum certified landing weight.  (FAA12)

Aircraft Approach Category A: Speed less than 91 knots.  (FAA12)

Aircraft Approach Category B: Speed 91 knots or more but less than 121 knots.  (FAA12)

Aircraft Approach Category C: Speed 121 knots or more but less than 141 knots.  (FAA12)

Aircraft Approach Category D: Speed 141 knots or more but less than 166 knots.  (FAA12)

Aircraft Approach Category E: Speed 166 knots or more.  (FAA12)

Aircraft Contact: Aircraft with which the Flight Service Stations (FSS) have established radio communications contact. One count is made for each en route, landing, or departing aircraft contacted by an FSS regardless of the number of contacts made with an individual aircraft during the same flight. A flight contacting five FSS's would be counted as five aircraft contacted.  (FAA2)   (FAA13)   (FAA14)

Aircraft Departure: An aircraft takeoff made at an airport.  (FAA15)

Aircraft Engine: An engine that is used or intended to be used for propelling aircraft. It includes turbosuperchargers, appurtenances, and accessories necessary for its functioning, but does not include propellers.  (14CFR1)

Aircraft Facility: (See also Airport; Heliport) An area where aircraft can take-off and land, usually equipped with associated buildings and facilities.  (DOI3)

Aircraft Incident: An occurrence, other than an accident, associated with the operation of an aircraft that affects or could affect the safety of operations and that is investigated and reported on FAA Form 8020-5.  (FAA3)

Aircraft Industry: Industry primarily engaged in the manufacture of aircraft, aircraft engines and parts including propellers and auxiliary equipment.  (AIA1)

Aircraft Miles Scheduled: The sum of the airport-to-airport distances of all flights scheduled, excluding those operated only as extra sections to accommodate traffic overflow.  (BTS5)

Aircraft Operations: The airborne movement of aircraft in controlled or non controlled airport terminal areas, and counts at en route fixes or other points where counts can be made.  (FAA14)

Aircraft Revenue Departures Performed: The number of aircraft take-offs actually performed in scheduled passenger/cargo and all-cargo services.  (BTS5)   (BTS6)

Aircraft Revenue Hours: The airborne hours in revenue service, computed from the moment an aircraft leaves the ground until it touches the ground again.  (BTS5)   (BTS6)

Aircraft Revenue Mile: The miles (computed in airport-to-airport distances) for each inter-airport hop actually completed in revenue service, whether or not performed in accordance with the scheduled pattern. For this purpose, operation to a flag stop is a hop completed even though a landing is not actually made. In cases where the inter-airport distances are inapplicable, aircraft miles flown are determined by multiplying the normal cruising speed for the aircraft type by the airborne hours.  (BTS5)   (BTS6)

Aircraft Type: A term used in a number of Federal Aviation Administration (FAA) publications in grouping aircraft by basic configuration: fixed-wing, rotorcraft, glider, dirigible, and balloon.  (FAA2)   (FAA6)   (FAA9)

Aircraft Type: A distinctive model of an aircraft as designated by the manufacturer.  (FAA15)

Aircraft-Miles: The distance flown by aircraft in terms of great circle airport-to-airport distances measured in statute miles.  (NTSB1)

Airframe: See also Aircraft, Airplane, Airship.

Airframe: Means the fuselage, booms, nacelles, cowlings, fairings, airfoil surfaces (including rotors but excluding propellers and rotating airfoils of engines), and landing gear of an aircraft and their accessories and controls.  (14CFR1)

Airframe: Structural components of an airplane, such as: fuselage, empennage, wings, landing gear, and engine mounts, but excluding such items as: engines, accessories, electronics, and other parts that may be replaced from time to time.  (AIA1)

Airline Transport Pilot: An airline transport pilot may act as a pilot-in-command of an aircraft engaged in air carrier service.  (FAA2)

Airman: A pilot, mechanic or other licensed aviation technician.  (FAA2)

Airman Certificate: A document issued by the Administrator of the Federal Aviation Administration certifying that the holder complies with the regulations governing the capacity in which the certificate authorizes the holder to act as an airman in connection with aircraft.  (FAA2)

Airman's Meteorological Information (AIRMET): In-flight weather advisories issued only to amend the area forecast concerning weather phenomena which are of operational interest to all aircraft and potentially hazardous to aircraft having limited capability because of lack of equipment, instrumentation, or pilot qualifications. Airman's Meteorological Information's (AIRMET) concern weather of less severity than that covered by Significant Meteorological Convective Information's (SIGMET) or Convective SIGMET's. AIRMET's cover moderate icing, moderate turbulence, sustained winds of 30 knots or more at the surface, widespread areas of ceilings less than 1,000 feet and/or visibility less than 3 miles, and extensive mountain obscurement.  (FAA4)

AIRMET: Airman's Meteorological Information  (FAA4)   (FAA8)

AIRNET: Airport Network Simulation Model  (FAA17)

Airplane: (See also Aircraft, Airframe, Airship) An engine-driven fixed-wing aircraft heavier than air, that is supported in flight by the dynamic reaction of the air against its wings.  (14CFR1)

Airplane Design Group: A grouping of airplanes based on wingspan.  (FAA12)

Airplane Design Group I: A wingspan up to but not including 49 feet (15 m).  (FAA12)

Airplane Design Group II: A wingspan 49 feet (15m) up to but not including 79 feet (24 m).  (FAA12)

Airplane Design Group III: A wingspan 79 feet (24m) up to but not including 118 feet (36 m).  (FAA12)

Airplane Design Group IV: A wingspan 118 feet (36m) up to but not including 171 feet (52 m).  (FAA12)

Airplane Design Group V: A wingspan 171 feet (52m) up to but not including 214 feet (65 m).  (FAA12)

Airplane Design Group VI: A wingspan 214 feet (65 m) up to but not including 262 feet (80 m).  (FAA12)

Airport: See also Aerodrome, Aircraft Facility, Heliport.

Airport: 1) An area of land or water that is used or intended to be used for the landing and takeoff of aircraft, and includes its buildings and facilities, if any; 2) Facility used primarily by conventional, fixed-wing aircraft; 3) A facility, either on land or water, where aircraft can take off and land. Usually consists of hard-surfaced landing strips, a control tower, hangars and accommodations for passengers and cargo; 4) A landing area regularly used by aircraft for receiving discharging passengers or cargo.  (14CFR1)   (FAA2)

Airport: Facility used primarily by conventional, fixed-wing aircraft.  (DOI3)

Airport Acceptance Rate (AAR): A dynamic input parameter specifying the number of arriving aircraft which an airport or airspace can accept from the Air Route Traffic Control Center per hour. The AAR is used to calculate the desired interval between successive arrival aircraft.  (FAA4)

Airport Advisory Area: The area within ten miles of an airport without a control tower or where the tower is not in operation, and on which a Flight Service Station is located.  (FAA4)

Airport Advisory Service: A service provided by flight service stations at airports not served by a control tower. This service consists of providing information to arriving and departing aircraft concerning wind direction/speed-favored runway, altimeter setting, pertinent known traffic/field conditions, airport taxi routes/traffic patterns, and authorized instrument approach procedures. This information is advisory in nature and does not constitute an Air Traffic Control (ATC) clearance.  (FAA2)   (FAA13)   (FAA14)

Airport and Airways Trust Fund: Mechanism for funding capital improvements for the nation's air traffic control system and airports. The fund is supported by taxes contributed by users of the aviation system, including an 10 percent tax of airline passengers and a tax on aviation fuel. Established by the Airport and Airway Revenue Act of 1970.  (FAA11)

Airport Elevation: The highest point on an airport's usable runways expressed in feet above mean sea level.  (FAA4)   (FAA12)

Airport Improvement Program (AIP): Provides funding from the Airport and Airway Trust Fund for airport development, airport planning, noise compatibility planning, and to carry out noise compatibility programs.  (FAA11)

Airport Information Desk: An airport unmanned facility designed for pilot self-service briefing, flight planning, and filing of flight plans.  (FAA4)

Airport Layout Plan (ALP): The plan of an airport showing the layout of existing and proposed airport facilities.  (FAA12)

Airport Lighting: Various lighting aids that may be installed on an airport.  (FAA4)

Airport Lighting (Runway Lights/Runway Edge Lights): Lights having a prescribed angle of emission used to define the lateral limits of a runway. Runway lights are uniformly spaced at intervals of approximately 200 feet, and the intensity may be controlled or preset.  (FAA4)

Airport Marking Aids: Markings used on runway and taxiway surfaces to identify a specific runway, a runway threshold, a centerline, a hold line, etc. A runway should be marked in accordance with its present usage such as: 1) Visual. 2) Nonprecision instrument. 3) Precision instrument.  (FAA4)

Airport Operations: The number of arrivals and departures from the airport at which the airport traffic control tower is located. There are two types of operations: local and itinerant.  (FAA13)

Airport Reference Dataset (AIRE): Regenerated annually from data provided by National Flight Data Center (NFDC).  (FAA11)

Airport Reference Point (ARP): The latitude and longitude of the approximate center of the airport.  (FAA12)

Airport Reservation Office (ARO): Office responsible for monitoring the operation of the high density rule. Receives and processes requests for Instrument Flight Rules (IFR) operations at high density traffic airports.  (FAA4)

Airport Runway Centerline Lighting: Flush centerline lights spaced at 60-foot intervals beginning 76 feet from the landing threshold and extending to within 75 feet of the opposite end of the runway.  (FAA4)

Airport Runway End Identifier Lighting (REIL): Two synchronized flashing lights, one on each side of the runway threshold, which provide rapid and positive identification of the approach end of a particular runway.  (FAA4)

Airport Surface Detection Equipment (ASDE): Radar equipment specifically designed to detect all principal features on the surface of an airport, including aircraft and vehicular traffic, and to present the entire image on a radar indicator console in the control tower. Used to augment visual observation by tower personnel of aircraft and/or vehicular movements on runways and taxiways.  (FAA4)

Airport Surveillance Radar (ASR): (See also Ground Controlled Approach, Precision Approach Radar) Approach control radar used to detect and display an aircraft's position in the terminal area. Airport Surveillance Radar (ASR) provides range and azimuth information but does not provide elevation data. Coverage of the ASR can extend up to 60 miles.  (FAA4)

Airport Taxi Charts: Designed to expedite the efficient and safe flow of ground traffic at an airport. These are identified by the official airport name (e.g, Washington National Airport).  (FAA4)

Airport Threshold Lighting: Fixed green lights arranged symmetrically left and right of the runway centerline, identifying the runway threshold.  (FAA4)

Airport Touchdown Zone Lighting: Two rows of transverse light bars located symmetrically about the runway centerline normally at 100 foot intervals. The basic system extends 3,000 feet along the runway.  (FAA4)

Airport Traffic: Aircraft operating in the air or on an airport surface exclusive of loading ramps and parking areas.  (FAA2)

Airport Traffic Control Service: Air traffic control service provided by an airport traffic control tower for aircraft operating on the movement area and in the vicinity of an airport.  (FAA2)

Airport Traffic Control Tower (ATCT): A central operations facility in the terminal air traffic control system, which consists of a tower cab structure, including an associated IFR room if radar equipped, and uses air/ground communications, radar, visual signaling, and other services to provide safe and expeditious movement of terminal air traffic.  (FAA2)

Airport Traffic Control Tower (ATCT): A terminal facility that uses air-ground radio communications, visual signaling, and other devices to provide Air Traffic Control (ATC) services to aircraft operating in the vicinity of an airport or on the movement area. Authorizes aircraft to land or takeoff at the airport controlled by the tower or to transit the airport traffic area regardless of flight plan or weather conditions (Instrument Flight Rules (IFR) or Visual Flight Rules (VFR)). A tower may also provide approach control services.  (FAA8)   (FAA13)   (FAA14)

Airport Visual Approach Slope Indicator Lighting (VASI): An airport lighting facility providing vertical visual approach slope guidance to aircraft during approach to landing by radiating a directional pattern of high intensity red and white focused light beams which indicate to the pilot that he is "on path" if he sees red/white, "above path" if white/white, and "below path " if red/red. Some airports serving large aircraft have three-bar Visual Approach Slope Indicators (VASI) which provide two visual glide paths to the same runway.  (FAA4)

Airport/Facility Directory: A publication designed primarily as a pilot's operational manual containing all airports, seaplane bases, and heliports open to the public including communications data, navigational facilities, and certain special notices and procedures. This publication is issued in seven volumes according to geographical area.  (FAA4)

Airports Grants In Aid Program: A grant of funds by the Secretary of Transportation under the Airport & Airway Improvement Act of 1982 to a sponsor for the accomplishment of one or more projects.  (FAA2)

Airports of Entry: Aircraft may land at these airports without prior permission to land from U.S. Customs.  (FAA2)

Airports, Flying Fields, and Airport Terminal Services: Establishments primarily engaged in operating and maintaining airports and flying fields, in servicing, repairing (except on a factory basis), maintaining and storing aircraft; and in furnishing coordinated handling services for airfreight or passengers at airports. This industry also includes private establishments primarily engaged in air traffic control operations.  (BOC1)

Airship: (See also Aircraft, Airframe, Airplane) An engine-driven lighter-than-air aircraft that can be steered.  (14CFR1)

Airspace Hierarchy: Within the airspace classes, there is a hierarchy and, in the event of an overlap of airspace: Class A preempts Class B. Class B preempts Class C, Class C preempts Class D, Class D preempts Class E. and Class E preempts Class G.  (FAA4)

Airspeed: The speed of an aircraft relative to its surrounding air mass. The unqualified term "airspeed", means one of the following. 1) Indicated Airspeed. The speed shown on the aircraft airspeed indicator. This is the speed used in pilot/controller communications under the general term "airspeed." 2) True Airspeed. The airspeed of an aircraft relative to undisturbed air. Used primarily in flight planning and en route portion of flight. When used in pilot/controller communications, it is referred to as "true airspeed" and not shortened to "airspeed."  (FAA4)

Airstart: The starting of an aircraft engine while the aircraft is airborne, preceded by engine shutdown during training flights or by actual engine failure.  (FAA4)

Airway: A Class E airspace area established in the form of a corridor, the centerline of which is defined by radio navigational aids.  (FAA4)

Airway Beacon: Used to mark airway segments in remote mountain areas. The light flashes Morse Code to identify the beacon site.  (FAA4)

AIT: Automated Information Transfer  (FAA4)

AIV: Aviation Impact Variable  (FAA17)

AL: Approach & Landing  (MTMC1)

AL: Arrival Locator  (MTMC1)

ALB: Albany County Airport  (FAA11)

Alcohol Concentration (AC): The concentration of alcohol in a person's blood or breath. When expressed as a percentage it means grams of alcohol per 100 milliliters of blood or grams of alcohol per 210 liters of breath.  (49CFR383)

Alcohol Involvement: A fatality or fatal crash as alcohol-related or alcohol involved if 1) Either a driver or a nonmotorist (usually a pedestrian) had a measurable or estimated blood alcohol concentration (BAC) of 0.01 grams per deciliter (g/dl) or above. Probabilities of alcohol involvement are now calculated for each driver, pedestrian, or crash. 2) Coded by police when evidence of alcohol is present. This code does not necessarily mean that a driver, passenger or nonoccupant was tested for alcohol.  (NHTSA1)   (NHTSA3)

Alert Notice: A request originated by a Flight Service Station (FSS) or an air route traffic control center (ARTCC) for an extensive communication search for overdue, unreported, or missing aircraft. Also known as Alnot.  (FAA4)

Alerting Service: A service provided to notify appropriate organizations regarding aircraft in need of search and rescue aid and assist such organizations as required.  (FAA4)

ALF: Accelerated Load Facility  (FHWA7)

All Clear: Term used in boating to mean 1) That a tow boat is ready to leave barge or 2) Is clear of an obstruction.  (TNDOT1)

All Services: The total of scheduled and nonscheduled transport services.  (BTS4)   (BTS5)   (FAA15)

All-Cargo and Mail Aircraft: Movements by aircraft and helicopters operated for commercial transport operations involving freight and/or mail, but not passengers.  (ACI1)

All-Cargo Carrier: One of a class of a carriers holding an All-Cargo Air Service Certificate issued under Section 418 of the Federal Aviation Act and certificated in accordance with Federal Aviation Regulations Part 121 to provide domestic air transportation of cargo.  (FAA11)

All-Cargo Carrier: An air carrier certificated in accordance with Federal Aviation Regulations (FAR) Part 121 to provide scheduled air freight, express,and mail transportation over specified routes, as well as to conduct nonscheduled operations that may include passengers.  (FAA14)

Allowance For Depreciation: Asset valuation account which includes the balance of the offsetting credit to be capitalized asset value-to represent the loss and deterioration in value of the asset over time, so that the asset is amortized over its useful life, and provisions are made for replacement of the asset at the end of its productive life.  (BTS4)

Allowance For Uncollectable Accounts: Accruals for estimated losses from uncollectible accounts.  (BTS4)

Alluvial Stream: Any stream whose banks are subject to attack, allowing channel meander. The stream has the property of depositing material such as soil, sand, or gravel and building up land in one area while washing it away in another.  (TNDOT1)

Alnot: See Alert Notice.

ALNOT: Alert Notice  (FAA8)

Alongside: The side of the ship. Goods to be delivered "alongside" are to be placed on the dock or lighter within reach of the ship's tackle so that they can be loaded aboard the ship.  (TNDOT1)

ALP: Airport Layout Plan  (FAA17)   (FAA12)

ALPA: Air Line Pilots Association  (FAA7)

Alphanumeric Display: Letters and numerals used to show identification (ID), altitude, beacon code, and other information concerning a target on a radar display.  (FAA4)

ALS: Approach Lighting System  (FAA17)

ALSF: Approach Lighting System With Sequenced Flashing Lights  (FAA19)

ALSF-I: Approach Light System With Sequenced Flashing Lights In ILS CAT-I Configuration  (FAA4)

ALSF-II: Approach Light System With Sequenced Flashing Lights In Ils CAT-II Modification  (FAA4)

ALSIP: Approach Lighting System Improvement Program  (FAA19)

Alternate Airport: An airport at which an aircraft may land if a landing at the intended airport becomes inadvisable.  (14CFR1)

Alternative Fuel Capacity: The on-site availability of apparatus to burn fuels other than natural gas.  (DOE1)

Altimeter Setting: The barometric pressure reading used to adjust a pressure altimeter for variations in existing atmospheric pressure or to the standard altimeter setting (29.92).  (FAA4)

Altitude: The vertical distance of a level, a point or an object considered as a point measured in feet Above Ground Level (AGL) or from Mean Sea Level (MSL). 1) MSL Altitude. Altitude expressed in feet measured from mean sea level. 2) AGL Altitude. Altitude expressed in feet measured above ground level. 3) Indicated Altitude. The altitude as shown by an altimeter. On a pressure or barometric altimeter it is altitude as shown uncorrected for instrument error and uncompensated for variation from standard atmospheric conditions.  (FAA4)

Altitude Encoding: An aircraft altitude transmitted via the Mode C transponder feature that is visually displayed in 100 feet increments on the ground radar scope having readout capability.  (FAA6)

Altitude Engine: A reciprocating aircraft engine having a rated takeoff power that is producible from sea level to an established higher altitude.  (14CFR1)

Altitude Readout: An aircraft's altitude, transmitted via the Mode C transponder feature, that is visually displayed in 100-foot increments on a radar scope having readout capability.  (FAA4)

Altitude Reservation (ALTRV): (See also Formation Flight) Airspace utilization under prescribed conditions normally employed for the mass movement of aircraft or other special requirements which cannot otherwise be accomplished. ALTRVs are approved by the appropriate Federal Aviation Administration (FAA) facility.  (FAA4)   (FAA8)

Altitude Restriction: An altitude or altitudes, stated in the order flown, which are to be maintained until reaching a specific point or time. Altitude restrictions may be issued by Air Traffic Control (ATC) due to traffic, terrain, or other airspace considerations.  (FAA4)   (FAA8)

Altitude Restrictions Are Canceled: Adherence to previously imposed altitude restrictions is no longer required during a climb or descent.  (FAA4)

ALTRV: Altitude Reservation  (FAA4)   (FAA8)

AM: Amplitude Modulation  (FAA19)

AMA: American Motorcyclist Association  (BTS)

AMASS: Airport Movement Area Safety System  (FAA17)   (FAA7)   (FAA19)

Ambulance or Rescue Service: Establishments primarily engaged in furnishing ambulances or rescue services, except by air, where such operations are primarily within a single municipality, contiguous municipalities, or a single municipality and its suburban areas.  (BOC1)

AMC: Air Mobility Command (Formerly Military Airlift Command)  (BTS7)

AMCC: ARTCC Maintenance Control Center  (FAA19)

Americans With Disabilities Act (ADA): The legislation defining the responsibilities of and requirements for transportation providers to make transportation accessible to individuals with disabilities.  (FTA1)

AMFA: Alternative Motor Fuels Act of 1988  (BTS8)

Amortization of Developmental and Preoperating Expenses, Etc.: Charges to expense for the 1) Amortization of capitalized developmental and preoperating cost and other intangible assets; and 2) Obsolescence and deterioration of flight equipment spare parts (included under depreciation and amortization).  (BTS4)

Amortization, Capital Leases: Charges applicable to assets recorded under capital leases.  (BTS4)

AMPD: Average Miles Driven Per Day  (DOE4)

AMS: Aeronautical Material Specification  (MTMC1)

AMSS: Aeronautical Mobile Satellite Service  (FAA17)

Amtrak: Operated by the National Railroad Passenger Corporation of Washington, DC. This rail system was created by President Nixon in 1970, and was given the responsibility for the operation of intercity, as distinct from suburban, passenger trains between points designated by the Secretary of Transportation.  (DOE6)

AMVER: Automated Mutual Assistance Vessel Rescue System  (FAA4)

An Easy Distance Off: A reasonably close (comfortable) distance off the bank, allowing ample room for maneuverability. This is a relative term depending upon size of stream and size of tow. The term "easy" pertains more to ease of mind than to closeness of distance and indicates that this portion of the river has no tight spots.  (TNDOT1)

ANA: Program Director for Automation  (FAA17)

ANB: Aids To Navigation Boat  (USCG5)

ANC: Anchorage International Airport  (FAA11)

Anchor It: Apply brakes for an emergency stop.  (ATA1)

Anchorage: An area where a vessel anchors or may anchor, either because of suitability or designation.  (DOI3)

AND: Associate Administrator for NAS Development  (FAA17)

ANG: Air National Guard  (FAA17)

Angle Collision: Collisions which are not head on, rear end, rear to rear, or sideswipe.  (NHTSA3)

ANICS: Alaskan NICS  (FAA19)

ANN: Program Director for Navigation and Landing  (FAA17)

Annual Operating Factor: The annual fuel consumption divided by the product of design firing rate and hours of operation per year.  (DOE5)

ANPRM: Advance Notice of Proposed Rulemaking  (NHTSA5)   (RSPA1)

ANS: NAS Transition Implementation Service  (FAA17)

ANSI: American National Standards Institute  (FHWA8)

Antenna: A metallic apparatus for sending and receiving electromagnetic waves.  (DOI4)

Antenna Array: A group of directional antennas.  (DOI4)

ANW: Program Director for Weather and Flight Service Stations  (FAA17)

AO: Air Observer  (MTMC1)

AO: Aviation Officer  (MTMC1)

AOA: Air Operations Area  (FAA1)

AOC: Aeronautical Operational Control  (FAA17)

AOC: Air Operations Center  (MTMC1)

AOCM: Aircraft Out of Commission for Parts  (MTMC1)

AOD: Aviation Officer of the Day  (MTMC1)

AOPA: Aircraft Owners and Pilots Association  (BTS7)

AOPL: Association of Oil Pipe Lines  (ENO1)

AOR: Operations Research Service  (FAA17)

APC: Air Project Coordinator  (MTMC1)

APC: Automatic Passenger Counter  (FTA4)

APF: Afloat Prepositioning Force  (MARAD4)

API: American Petroleum Institute  (DOE8)

APL: Airport Lights  (FAA16)

APL: American President Lines, Ltd.  (MARAD4)

APM: All Pilots Meeting  (MTMC1)

APM: Automated People Mover  (MOCD)   (TXDOT)

APMS: Automated Performance Measurement System  (FAA7)

APO: Office of Aviation Policy and Plans  (FAA17)

APOD: Aerial Port of Debarkation  (MTMC1)

APOE: Aerial Port of Embarkation  (MTMC1)

APORTS: Aerial Ports and Air Operating Bases  (MTMC1)

APP: Office of Airport Planning and Programming  (FAA17)

Appliance: Any instrument, mechanism, equipment, part, apparatus, appurtenance or accessory, including communications equipment, that is used or intended to be used in operating or controlling an aircraft in flight, is installed in or attached to the aircraft, and is not part of an airframe, engine, or propeller.  (14CFR1)

Applicant: A governmental entity, a non-profit public-purpose organization, or any responsible person having the legal, financial, and technical capacity to implement an intermodal passenger terminal project under 49 CFR 256. The applicant must have legal authority to receive and expend Federal funds.  (49CFR256)

Apportionment: (See also Passenger Facility Charge) Distribution of Airport Improvement Plan (AIP) funds from the Airport & Airways Trust Fund to airport sponsors based on enplanements or cargo landed weights. Also referred to as entitlement.  (FAA11)

Approach Clearance: Authorization by Air Traffic Control (ATC) for a pilot to conduct an instrument approach. The type of instrument approach for which a clearance and other pertinent information is provided in the approach clearance when required.  (FAA4)

Approach Control Facility: A terminal air traffic control facility providing approach control service.  (FAA2)   (FAA4)   (FAA13)   (FAA14)

Approach Control Service: Air traffic control service provided by an approach control facility for arriving and departing Visual Flight Rules (VFR)/Instrument Flight Rule (IFR) aircraft and, on occasion, en route aircraft. At some airports not served by an approach control facility, the Air Route Traffic Control Center (ARTCC) provides limited approach control service.  (FAA2)   (FAA4)   (FAA13)   (FAA14)

Approach Gate: An imaginary point used within Air Traffic Control (ATC) as a basis for vectoring aircraft to the final approach course. The gate will be established along the final approach course 1 mile from the outer marker (or the fix used in lieu of the outer marker) on the side away from the airport for precision approaches and 1 mile from the final approach fix on the side away from the airport for nonprecision approaches. In either case when measured along the final approach course, the gate will be no closer than 6 miles from the landing threshold.  (FAA4)

Approach Light System (ALS): An airport lighting facility which provides visual guidance to landing aircraft by radiating light beams in a directional pattern by which the pilot aligns the aircraft with the extended centerline of the runway on his final approach for landing. Condenser-Discharge Sequential Flashing Lights/Sequenced Flashing Lights may be installed in conjunction with the Approach Lighting System (ALS) at some airports. Types of Approach Light Systems are: 1) (ALSF-1) Approach Light System with Sequenced Flashing Lights in Instrument Landing System (ILS) Cat-I configuration. 2) (ALSF-2) Approach Light System with Sequenced Flashing Lights in ILS Cat-II configuration. The ALSF-2 may operate as a Simplified Short Approach Light System with Runway Alignment Indicator Lights (SSALR) when weather conditions permit. 3) Simplified Short Approach Light System with Sequenced Flashing Lights (SSALF). 4) Simplified Short Approach Light System with Runway Alignment Indicator Lights (SSALR). 5) (MALSF) Medium Intensity Approach Light System with Sequenced Flashing Lights. 6) Medium Intensity Approach Light System with Runway Alignment Indicator Lights (MALSR). 7) Lead-in-light system (LDIN): Consists of one or more series of flashing lights installed at or near ground level that provides positive visual guidance along an approach path, either curving or straight, where special problems exist with hazardous terrain, obstructions, or noise abatement procedures. 8) Runway Alignment Indicator Lights (RAIL) (Sequenced Flashing Lights which are installed only in combination with other light systems). 9) Omnidirectional Approach Lighting System consists of seven omnidirectional flashing lights located in the approach area of a nonprecision runway (ODALS). Five lights are located on the runway centerline extended with the first light located 300 feet from the threshold and extending at equal intervals up to 1,500 feet from the threshold. The other two lights are located, one on each side of the runway threshold, at a lateral distance of 40 feet from the runway edge, or 75 feet from the runway edge when installed on a runway equipped with a Visual Approach Slope Indicator (VASI).  (FAA4)

Approach Locking: Electric locking effective while a train is approaching, within a specified distance, a signal displaying an aspect to proceed, and which prevents, until after the expiration of a predetermined time interval after such signal has been caused to display its most restrictive aspect, the movement of any interlocked or electrically locked switch, movable-point frog, or derail in the route governed by the signal, and which prevents an aspect to proceed from being displayed for any conflicting route.  (49CFR236)

Approach Sequence: The order in which aircraft are positioned while on approach or awaiting approach clearance.  (FAA4)

Approach Signal: A roadway signal used to govern the approach to another signal and if operative so controlled that its indication furnishes advance information of the indication of the next signal.  (49CFR236)

Approach Speed: The recommended speed contained in aircraft manuals used by pilots when making an approach to landing. This speed will vary for different segments of an approach as well as for aircraft weight and configuration.  (FAA4)

Approachway: The airspace through which aircraft approach or leave a landing area.  (DOI4)

Appropriate Air Traffic Service (ATS) Authority: The relevant authority designated by the State responsible for providing air traffic services (ATS) in the airspace concerned. In the United States, the "appropriate ATS authority" is the Director, Office of Air Traffic System Management, ATM-1.  (FAA4)

Appropriate Authority: 1) Regarding flight over the high seas: the relevant authority is the State of Registry. 2) Regarding flight over other than the high seas: the relevant authority is the State having sovereignty over the territory being overflown.  (FAA4)

Approved: A term used to indicate Coast Guard approval of a specific item among the limited number that the Coast Guard has been directed by law to test and "approve." Some of these items are personal flotation devices, fire extinguishers, carburetor backfire flame arresters, distress signals, and certain types of life rafts. The standards program has not required "approval" of any boat or item of associated equipment.  (USCG1)

Apron: 1) A floor or lining-of resistant material at the toe of a dam or bottom of a spillway to prevent erosion from turbulent water flow; 2) That portion of a pier and wharf measured between the outer edges of the water-facing side and the transit shed or other inshore structure.  (TNDOT1)

APS: Airway Planning Standard  (FAA19)

APT: Accelerated Pavement Testing  (FHWA7)

APTA: American Public Transit Association  (BTS8)

APTS: Advanced Public Transportation System  (FTA4)

AQP: Advanced Qualification Program  (FAA7)

Aqueduct: (See also Canal/Ditch) A structure designed to transport domestic or industrial water from a supply source to a distribution point, often by gravity.  (DOI3)

AR 55-80: Highways for National Defense  (MTMC1)

ARAC: Aviation Regulatory Advisory Committee  (FAA7)

ARAN: Automatic Road Analyzer  (FHWA8)

Arch: A curved structure that supports the weight of material over an open space.  (DOI4)

ARD: Research and Development Service  (FAA17)

Area Control Center: An International Civil Aviation Organization (ICAO) term for an air traffic control facility primarily responsible for Air Traffic Control (ATC) services being provided Instrument Flight Rules (IFR) aircraft during the en route phase of flight. The U.S. equivalent facility is an air route traffic control center.  (FAA4)

Area Control Computer Complex (ACCC): The common automation system equipment and software that support control of aircraft in a specific area, and which is located within each area control facility. The Area Control Computer Complex (ACCC) is one portion of the AAS (Advanced Automation System).  (FAA8)

Area Control Facility (ACF): [As of 1992] The planned 23 facilities that result from consolidation of existing Air Route Traffic Control Center (ARTCC) and Terminal Radar Approach Control (TRACON)/Terminal Radar Approach Control in Tower Cab (TRACAB) facilities. An Area Control Facility (ACF) may be formed from an existing ARTCC or may be created in a new building. The number, location, and implementation dates of ACFs are in accordance with the National Airspace System Plan. There will be 20 Continental U.S. (CONUS) ACFs converted from ARTCCs; plus Honolulu, Anchorage, and the New York TRACON. Each can accomplish an en route and approach/departure control.  (FAA8)

Area Navigation (RNAV): A method of navigation that permits aircraft operation on any desired course within the coverage of station-referenced navigation signals or within the limits of a self-contained system capability. Random area navigation routes are direct routes, based on area navigation capability, between waypoints defined in terms of latitude/longitude coordinates, degree/distance fixes, or offsets from published or established routes/airways at a specified distance and direction. The major types of equipment are: 1) Combined VOR and TACAN navigational facility (VORTAC) referenced or Course Line Computer (CLC) systems, which account for the greatest number of Radio Navigation (RNAV) units in use. To function, the CLC must be within the service range of a VORTAC. 2) OMEGA/VLF, Although two separate systems, can be considered as one operationally. A long-range navigation system based upon Very Low Frequency (VLF) radio signals transmitted from a total of 17 stations worldwide. 3) Inertial navigation systems (INS), which are totally self-contained and require no information from external references. They provide aircraft position and navigation information in response to signals resulting from inertial effects on components within the system. 4) Microwave Landing System (MLS) Area Navigation (MLS/RNAV), which provides area navigation with reference to an MLS ground facility. 5) LORAN-C is a long-range radio navigation system that uses ground waves transmitted at low frequency to provide user position information at ranges of up to 600 to 1,200 nautical miles at both en route and approach altitudes. The usable signal coverage areas are determined by the signal-to-noise ratio, the envelope-to-cycle difference, and the geometric relationship between the positions of the user and the transmitting stations.  (FAA4)

Area Navigation (RNAV): A method of using navigation instruments that allows pilots flexibility to fly direct routes between waypoints or offset from published or established routes/airways at specified distance and direction.  (FAA6)

Area to Be Submerged: The known extent of the intended lake that will be created behind a dam under construction.  (DOI3)

Area Wide Template: A computerized format (spreadsheet) for data entry of system length, vehicle travel, population, net land area, fatal and injury accidents, and percent of travel by vehicle type.  (FHWA2)

ARF: Airport Reservation Function  (FAA17)

ARFF: Aircraft Rescue & Fire Fighting  (FAA16)

ARINC: Aeronautical Radio Incorporated  (FAA4)   (FAA17)   (FAA7)   (FAA19)   (FAA8)

Arising from the Operation of a Railroad: Includes all activities of a railroad which are related to the performance of its rail transportation business.  (49CFR225)

Armed Forces: The Army, Navy, Air Force, Marine Corps, and Coast Guard, including their regular and reserve components and members serving without component status.  (14CFR1)

Armstrong Starter: Old-fashioned hand crank.  (ATA1)

Army Aviation Flight Information Bulletin: A bulletin that provides air operation data covering Army, National Guard, and Army Reserve aviation activities.  (FAA4)

ARO: Airport Reservation Office  (FAA4)

ARP: Airport Reference Point  (FAA12)

ARPA: Advanced Research Projects Agency  (NHTSA5)

Arrangement of Passenger Transportation: Includes establishments engaged in providing travel information and acting as agents in arranging tours, transportation, car rentals, and lodging for travelers.  (BEA1)

Arrangement of Passenger Transportation Not Elsewhere Classified: Establishments primarily engaged in arranging passenger transportation (other than travel agencies and tour operators), such as ticket offices (not operated by transportation companies) for railroads, buses, ships, and airlines.  (BOC1)

Arresting System: A safety device consisting of two major components, name, engaging or catching devices and energy absorption devices for the purpose of arresting both tailhook and/or nontailhook-equipped aircraft. It is used to prevent aircraft from overrunning runways when the aircraft cannot be stopped after landing or during aborted takeoff. Arresting systems have various names; (e.g., arresting gear, hook device, wire barrier cable).  (FAA4)

Arrival Aircraft Interval (AAI): An internally generated program in hundredths of minutes based upon the Airport Acceptance Rate. Arrival Airport Interval is the desired optimum interval between successive arrival aircraft over the vertex.  (FAA4)

Arrival Center: The air route traffic control center having jurisdiction for the impacted airport.  (FAA4)

Arrival Delay: A parameter which specifies a period of time in which no aircraft will be metered for arrival at the specified airport.  (FAA4)

Arrival Post: A signboard placed approximately 1/2 mile below the lock on the upstream and the downstream side to inform the pilot of the towboat that he has arrived at the lock and his preference is rated upon his first arrival either below or above. This term is falling into disuse since the advent of radio communications between towboats and the lock.  (TNDOT1)

Arrival Program Sequencing: The automated program designed to assist in sequencing aircraft destined for the same airport.  (FAA4)

Arrival Sector: An operational control sector containing one or more meter fixes.  (FAA4)

Arrival Time: The time an aircraft touches down on arrival.  (FAA4)

ARS: Average Rectified Slope  (FHWA8)

ARSA: Airport Radar Service Area  (FAA17)   (FAA8)

ARSI: Automated Roadside Safety Inspection  (FHWA15)

ARSR: Air Route Surveillance Radar  (FAA2)   (FAA4)   (FAA19)   (FAA8)

ART: Air Reserve Technician  (MTMC1)

ARTBA: American Road and Transportation Builders Association  (FHWA15)

ARTCC: Air Route Traffic Control Center  (FAA2)   (FAA3)   (FAA4)   (FAA17)   (FAA19)   (FAA14)   (FAA13)

Arterial Highway: (See also Freeway, Minor Arterial, Principal Arterial) Arterial highways serve major traffic movements or major traffic corridors. While they may provide access to abutting land, their primary function is to serve traffic moving through the area.  (FHWA5)

Arterial Street: A major thoroughfare, used primarily for through traffic rather than for access to adjacent land, that is characterized by high vehicular capacity and continuity of movement.  (APTA1)

Articulated Bus: A bus usually 55 feet or more in length with two connected passenger compartments that bends at the connecting point when the bus turns a corner.  (APTA1)

Articulated Motor Buses: Extra-long (54 ft. to 60 ft.) motor buses with the rear body section connected to the main body by a joint mechanism. The joint mechanism allows the vehicles to bend when in operation for sharp turns and curves, and yet have a continuous interior.  (FTA1)

ARTS: Advanced Rural Transportation Systems  (FHWA15)

ARTS: Automated Radar Terminal System  (FAA4)   (FAA17)   (FAA7)   (FAA19)

ARZ: Auto-Restriced Zone  (TRB1)

ASAP: As Soon As Possible

ASAS: Aviation Safety Analysis System  (FAA19)

ASC: Office of System Capacity and Requirements  (FAA17)

ASCE: American Society of Civil Engineers  (ENO1)

ASCP: Aviation System Capacity Plan  (FAA17)

ASD: Aircraft Situation Display  (FAA4)   (FAA17)

ASDA: Accelerate - Stop Distance Available  (FAA4)   (FAA12)

ASDE: Airport Surface Detection Equipment  (FAA4)   (FAA17)   (FAA7)   (FAA19)   (FAA8)

ASE: Automated Speed Enforcement  (MM)

ASE: NAS System Engineering Service  (FAA17)

ASIA: Aviation Security Improvement Act  (FAA1)

ASLAR: Aircraft Surge Launch and Recovery  (FAA4)

ASM: Available Seat Mile  (FAA14)

ASOS: Automated Surface Observation System  (FAA17)   (FAA19)

ASP: Arrival Sequencing Program  (FAA4)   (FAA19)

ASP: Aviation Safety Program  (FAA7)

Aspect: The appearance of a roadway signal conveying an indication as viewed from the direction of an approaching train; the appearance of a cab signal conveying an indication as viewed by an observer in the cab.  (49CFR236)

Asphalt: A dark-brown-to-black cement-like material containing bitumens as the predominant constituents obtained by petroleum processing. The definition includes crude asphalt as well as the following finished products: cements, fluxes, the asphalt content of emulsions (exclusive of water), and petroleum distillates blended with asphalt to make cutback asphalts.  (DOE3)

ASQP: Airline Service Quality Performance  (FAA17)

ASR: Airport Surveillance Radar  (FAA2)   (FAA4)   (FAA17)   (FAA7)   (FAA19)

ASRS: Aviation Safety Reporting System  (BTS7)

Assigned Vehicle: A vehicle provided to an organizational element of a government agency or contractor by General Services Administration's (GSA) Interagency Fleet Management System for a period of more than 30 days.  (GSA1)

Associated Equipment: Any system, part or component of a boat as originally manufactured or any similar part or component manufactured or sold for replacement, repair, or improvement of such system, part, or component; any accessory or equipment for, or appurtenance to, a boat; and any marine safety article, accessory, or equipment intended for use by a person on board a boat; but excluding radio equipment, as designated by the Secretary [of Transportation] under 46 U.S.C. 2101.  (USCG1)

ASSP: Automated Seavan Shipment Planning System  (MTMC1)

AST&L: American Society of Transportation and Logistics  (MTMC1)

ASTA: Airport Surface Traffic Automation  (FAA17)   (FAA7)   (FAA19)

ASTA: American Society of Travel Agents  (MTMC1)

Astern: 1) Behind a vessel; 2) Move in a reverse direction.  (MARAD2)

ASTM: American Society for Testing and Materials  (DOE3)   (DOE8)

Astronautics: Art and science of designing, building, and operating manned or unmanned space objects.  (AIA1)

AT: Air Traffic  (FAA19)

At Anchor: Held in place in the water by an anchor. Includes "moored" to a buoy or anchored vessel and "dragging anchor".  (USCG2)

At Grade: See also Grade Crossings, Highway-Rail Crossing.

At Grade, Exclusive Right-of-Way: Railway right-of-way from which all other traffic, mixed and cross, is excluded. Median strip right-of-way is included provided all crossings of the right-of-way pass over or under the median.  (FTA1)

At Grade, Mixed and Cross Traffic: Railway right-of-way over which other traffic moving in the same direction or the cross directions may pass. City street right-of-way is included.  (FTA1)

At Grade, with Cross Traffic: Railway right-of-way over which no other traffic may pass, except to cross at grade-level crossings. A median strip right-of-way with grade-level crossings at intersecting streets is included.  (FTA1)

ATA: Air Transport Association of America  (MTMC1)

ATA: American Trucking Associations  (BTS2)

ATADS: FAA Air Traffic Activity Data Base System  (BTS7)

ATAP: Anti-Terrorism Assistance Program  (FAA1)

ATB: Asphalt Treated Base  (FHWA7)

ATC: Air Tactical Communications  (FAA7)

ATC: All Terrain Cycle  (NHTSA3)

ATC: Air Traffic Control  (FAA2)   (FAA4)   (FAA17)   (FAA19)   (FAA8)

ATCA: Air Traffic Control Association  (ENO1)

ATCAA: Air Traffic Control Assigned Airspace  (FAA4)   (FAA17)

ATCBI: Air Traffic Control Beacon Interrogator  (FAA19)

ATCCC: Air Traffic Control Command Center  (FAA8)

ATCO: Air Taxi Commercial Operator  (FAA11)

ATCRBS: Air Traffic Control Radar Beacon System  (FAA19)   (FAA8)

ATCSCC: Air Traffic Control System Command Center  (FAA4)   (FAA17)   (FAA7)   (FAA19)

ATCT: Airport Traffic Control Tower  (FAA2)   (FAA4)   (FAA19)   (FAA8)   (FAA13)

ATD: Anthropomorphic Test Device  (MM)

ATE: Automatic Test Equipment  (FAA19)

ATIS: Advanced Traveler Information System  (FTA4)

ATIS: Automatic Terminal Information Service  (FAA4)   (FAA17)   (FAA19)

ATK HEL: Attack Helicopter  (MTMC1)

ATL: William B Hartsfield Atlanta International Airport  (FAA11)

ATLAS: All Terrain Lifter Articulated System  (MTMC1)

ATM: Air Traffic Management  (FAA7)

ATMS: Advanced Traffic Management System  (FAA17)   (FTA4)

ATN: Aeronautical Telecommunications Network  (FAA17)   (FAA7)   (FAA19)

ATO: Air Traffic Operations Service  (FAA17)

ATO: Automatic Train Operation  (TRB1)

ATOMS: Air Traffic Operations Management System  (FAA17)

ATON: Aids To Navigation  (USCG5)

ATP: Automatic Train Protection  (TRB1)

ATPAC: Air Traffic Procedures Advisory Committee  (FAA7)

ATR: Automatic Traffic Recorder  (FHWA7)

ATS: Air Traffic Services  (FAA4)

ATS: American Travel Survey  (BTS2)

ATS: Automatic Train Supervision  (FTA4)

ATSF: Atchison, Topeka and Santa Fe Railroad  (BTS8)

ATT: Advanced Transport Telematics  (FHWA15)

ATTLA: Air Transportability Test Loading Agency  (MTMC1)

ATV: Accurate Traffic Volume  (BTS8)

ATV: All Terrain Vehicle  (NHTSA3)

AUS: Robert Mueller Municipal Airport  (FAA11)

Authorized Altitude: A published altitude representing the maximum usable altitude or flight level for an airspace structure or route segment. It is the highest altitude on a federal airway, jet route, area navigation low or high route, or other direct route for which a Minimum En Route Instrument Flight Rules (IFR) Altitude (MEA) is designated in Part 95 at which adequate reception of navigation aid signals is assured.  (FAA4)

Auto Restricted Zone: An area in which normal automobile traffic is prohibited or limited to certain times, and vehicular traffic is restricted to public transit, emergency vehicles, taxicabs and, in some cases, delivery of goods.  (APTA1)

AUTOBILL: Automotive Billing Module  (GSA2)

Autoland Approach: (See also Coupled Approach) A precision instrument approach to touchdown and, in some cases, through the landing rollout. An autoland approach is performed by the aircraft autopilot which is receiving position information and/or steering commands from onboard navigation equipment.  (FAA4)

Automated Flight Service Station: A station that provides interactive alphanumeric and graphic work stations for the flight service specialist.  (FAA8)

Automated Guideway: An electric railway operating without vehicle operators or other crew on board the vehicle.  (APTA1)

Automated Guideway: One or more automatically controlled vehicles operating over an exclusive guideway.  (FTA2)

Automated Guideway Transit: Guided transit vehicles operating singly or in multi-car trains with a fully automated system (no crew on transit units). Service may be on a fixed schedule or in response to a passenger-activated call button. Automated guideway transit includes personal rapid transit, group rapid transit and people mover systems.  (FTA1)

Automated Guideway Transit System: Fixed-guideway transit system which operates with automated (driverless) individual vehicles or multi-car trains. Service may be on a fixed schedule or in response to a passenger-activated call button.  (49CFR137)

Automated Guideway Vehicles: Guided transit passenger vehicles operating under a fully automated system (no crew on transit units).  (FTA1)

Automated Mutual Assistance Vessel Rescue System (AMVER): A facility which can deliver, in a matter of minutes, a Surface Picture (SURPIC) of vessels in the area of a potential or actual search and rescue incident, including their predicted positions and their characteristics.  (FAA4)

Automated Radar Terminal System (ARTS): The generic term for the ultimate in functional capability afforded by several automation systems. Each differs in functional capabilities and equipment. Automated Radar Terminal System (ARTS) plus a suffix roman numeral denotes a specific system. A following letter indicates a major modification to that system. In general, an ARTS displays for the terminal controller aircraft identification, flight plan data, other flight associated information; e.g. altitude, speed, and aircraft position symbols in conjunction with his radar presentation. Normal radar co-exists with the alphanumeric display. In addition to enhancing visualization of the air traffic situation, ARTS facilitate intra/inter-facility transfer and coordination of flight information. These capabilities are enabled by specially designed computers and subsystems tailored to the radar and communications equipments and operational requirements of each automated facility. Modular design permits adoption of improvements in computer software and electronic technologies as they become available while retaining the characteristics unique to each system.  (FAA4)

Automated Radar Terminal Type II System (ARTS II): A programmable nontracking computer-aided display subsystem capable of modular expansion. Automated Radar Terminal System (ARTS) II systems provide a level of automated air traffic control capability at terminals having low to medium activity. Flight identification and altitude may be associated with the display of secondary radar targets. The system has the capability of communicating with Air Route Traffic Control Centers (ARTCC) and other ARTS II, IIA, II and IIA facilities.  (FAA4)

Automated Radar Terminal Type IIA System (ARTS IIA): A programmable radar-tracking computer subsystem capable of modular expansion. The Automated Radar Terminal System (ARTS) IIA detects, tracks, and predicts secondary radar targets. The targets are displayed by means of computer-generated symbols, ground speed, and flight plan data. Although it does not track primary radar targets, they are displayed coincident with the secondary radar as well as the symbols and alphanumerics. The system has the capability of communicating with ARTCC's and other ARTS II, IIA, III, and IIIA facilities.  (FAA4)

Automated Radar Terminal Type III System (ARTS III): The Beacon Tracking Level of the modular programmable automated radar terminal system in use at medium to high activity terminals. ARTSIII detects, tracks, and predicts secondary radar-derived aircraft targets. These are displayed by means of computer-generated symbols and alpha numeric characters depicting flight identification, aircraft altitude, ground speed, and flight plan data. Although it does not track primary targets, they are displayed coincident with the secondary radar as well as the symbols and alphanumerics. The system has the capability of communicating with ARTCC's and other Automated Radar Terminal System (ARTS) III facilities.  (FAA4)

Automated Radar Terminal Type IIIA System (ARTS IIIA): The Radar Tracking and Beacon Tracking Level (RT&BTL) of the modular, programmable automated radar terminal system. Automated Radar Terminal System (ARTS) IIIA detects, tracks, and predicts primary as well as secondary radar-derived aircraft targets. This more sophisticated computer-driven system upgrades the existing ARTS III system by providing improved tracking, continuous data recording, and fail-safe capabilities.  (FAA4)

Automated Radar Tracking System: An automated radar and radar beacon tracking system. Its functional capabilities and design are essentially the same as the terminal Automated Radar Terminal System (ARTS) IIIA system except for the En Route Automated Radar Systems (EARTS) capability of employing both short-range Airport Surveillance Radar (ASR) and long-range Air Route Surveillance Radar (ARSR) radars, use of full digital radar displays, and fail-safe design.  (FAA4)

Automated Transfer Information: A precoordinated process, specifically defined in facility directives, during which a transfer of altitude control and/or radar identification is accomplished without verbal coordination between controllers using information communicated in a full data block.  (FAA4)

Automatic Altitude Reporting: That function of a transponder which responds to Mode C interrogations by transmitting the aircraft's altitude in 100-foot increments.  (FAA4)

Automatic Block Sign System: A block signal system wherein the use of each block is governed by an automatic block signal, cab signal, or both.  (49CFR236)

Automatic Carrier Landing System: U.S. Navy final approach equipment consisting of precision tracking radar coupled to a computer data link to provide continuous information to the aircraft, monitoring capability to the pilot, and a backup approach system.  (FAA4)

Automatic Direction Finder (ADF): An aircraft radio navigation system which senses and indicates the direction to a Low/Medium Frequency (L/MF) nondirectional radio beacon (NDB) ground transmitter. Direction is indicated to the pilot as a magnetic bearing or as a relative bearing to the longitudinal axis of the aircraft depending on the type of indicator installed in the aircraft. In certain applications, such as military, ADF operations may be based on airborne and ground transmitters in the VHF/UHF frequency spectrum.  (FAA4)   (FAA6)

Automatic Fare Collection (AFC) System: The controls and equipment that automatically admit passengers on insertion of the correct fare in an acceptable form, which may be coins, tokens, tickets, or farecards (stored value farecards must be inserted again on exit, at which point an additional fare may be required).  (TRB1)

Automatic Interlocking: An arrangement of signals, with or without other signal appliances, which functions through the exercise of inherent powers as distinguished from those whose functions are controlled manually, and which are so interconnected by means of electric circuits that their movements must succeed each other in proper sequence, train movements over all routes being governed by signal indication.  (49CFR236)

Automatic Pilot: The roll, pitch, and yaw axis of an aircraft can be controlled by use of an automatic pilot. Information from very high frequency omni-directional radio range (VOR), instrument landing systems (ILS), microwave landing systems (MLS), and other navigation aids can be coupled to the automatic pilot for en route and approach flights.  (FAA6)   (FAA10)

Automatic Restraint System: Any restraint system that requires no action on the part of the driver or passengers to be effective in providing occupant crash protection (e.g., air bags or passive belts).  (NHTSA1)

Automatic Terminal Information Service: The continuous broadcast of recorded noncontrol information in selected terminal areas. Its purpose is to improve controller effectiveness and to relieve frequency congestion by automating the repetitive transmission of essential but routine information.  (FAA4)

Automatic Train Control System: A system so arranged that its operation will automatically result in the following; 1) A full service application of the brakes which will continue either until the train is brought to a stop, or, under control of the engineman, its speed is reduced to a predetermined rate; 2) When operating under a speed restriction, an application of the brakes when the speed of the train exceeds the predetermined rate and which will continue until the speed is reduced to that rate.  (49CFR236)

Automatic Train Stop System: A system so arranged that its operation will automatically result in the application of the brakes until the train has been brought to a stop.  (49CFR236)

Automatic Vehicle Location System: A system that senses, at intervals, the location of vehicles carrying special electronic equipment that communicates a signal back to a central control facility.  (TRB1)

Automatic Vehicle Monitoring System: A system in which electronic equipment on a vehicle sends signals back to a central control facility, locating the vehicle and providing other information about its operations or about its mechanical condition.  (TRB1)

Automobile: See also Bus, Car, Minivan, Motor Vehicle, Taxi, Vehicle.

Automobile: Any 4-wheeled vehicle propelled by fuel which is manufactured primarily for use on public streets, roads, and highways (except any vehicle operated exclusively on a rail or rails), and that either 1) Is rated at 6,000 pounds gross vehicle weight or less; or 2) Which a) is rated more than 6,000 pound gross vehicle weight, but less than 10,000 pounds gross vehicle weight; b) is a type of vehicle for which the [National Highway Traffic Safety Administration (NHTSA)] Administrator determines, under paragraph b) of 49 CFR 523, average fuel economy standards are feasible; and c) is a type of vehicle for which the Administrator determines, under paragraph b) of 49 CFR 523, average fuel economy standards will result in significant energy conservation, or is a type of vehicle which the Administrator determines, under paragraph b) of 49 CFR 523, is substantially used for the same purposes as vehicles described in 1) above.  (49CFR523)

Automobile: A privately owned and/or operated licensed motorized vehicle including cars, jeeps and station wagons. Leased and rented cars are included if they are privately operated and not used for picking up passengers in return for fare.  (FHWA3)

Automobile: Passenger cars, up to and including station wagons in size.  (FTA1)

Automobile Size Classification: Automobile size classifications as established by the Environmental Protection Agency (EPA): Minicompact - less than 85 cubic feet of passenger and luggage volume; Subcompact - between 85 to 100 cubic feet of passenger and luggage volume; Compact - between 100 to 110 cubic feet of passenger and luggage volume; Midsize - between 110 to 120 cubic feet of passenger and luggage volume; Large - more than 120 cubic feet of passenger and luggage volume; Two seater - automobiles designed primarily to seat only two adults. Station wagons are included with the size class for the sedan of the same name.  (DOE6)

Automobile Transporter Body: Truck body designed for the transportation of other vehicles.  (ATA1)

Automotive Billing Module (AutoBill): This module creates non-GSA customer billing tapes and General Services Administration (GSA) interfund transactions from billing records generated in the Transportation Interface and Reporting System (TIRES) and generates monthly accounting transaction information to send to the NEAR (National Electronic Accounting and Reporting) system.  (GSA2)

Automotive Payment Module (AutoPay): This module processes all maintenance and extended warranty vendor invoices entered into the Fleet Service Station (FSS) Fleet Management System by the Maintenance Control Centers and processes the rental authorization records for commercial rent-a-car rentals from the Fleet Management Center.  (GSA2)

AUTOPAY: Automotive Payment Module  (GSA2)

Autorotation: A rotorcraft flight condition in which the lifting rotor is driven entirely by action of the air when the rotorcraft is in motion. 1. Autorotative Landing/Touchdown Autorotation. Used by a pilot to indicate that he will be landing without applying power to the rotor. 2. Low Level Autorotation. Commences at an altitude well below the traffic pattern, usually below 100 feet AGL and is used primarily for tactical military training. 3. 180 degrees Autorotation. Initiated from a downwind heading and is commenced well inside the normal traffic pattern. "Go around" may not be possible during the latter part of this maneuver.  (FAA4)

Auxiliary Lock: [with respect to rail operations] A smaller secondary lock adjacent to the main lock.  (TNDOT1)

Auxiliary Rotor: A rotor that serves either to counteract the effect of the main rotor torque on a rotorcraft or to maneuver the rotorcraft about one or more of its three principal axes.  (14CFR1)

Available Flight Stage Length: The average distance covered per aircraft hop in revenue services, from take-off to landing. Derived by dividing the total aircraft miles flown in revenue service by the number of aircraft revenue departures performed.  (BTS6)

Available Seat Mile: One seat transported one mile.  (ATAB1)

Available Seat Mile (ASM): The aircraft miles flown in each inter-airport hop multiplied by the number of seats available on that hop for revenue passenger use.  (BTS5)   (BTS6)   (FAA14)

Available Ton Mile: One ton of capacity (passengers and cargo) transported one mile.  (ATAB1)

Available Ton Miles: The aircraft miles flown in each inter-airport hop multiplied by the capacity available (in tons) for that hop.  (BTS6)

Available Tons Per Aircraft Mile: The average total passenger/cargo carrying capacity (tons) offered for sale per aircraft per aircraft mile, derived by dividing the overall available ton miles by the total aircraft miles flown in revenue service.  (BTS6)

AVAS: Automated Voice Annunciator Systems  (FTA4)

AVC: Automatic Vehicle Classification  (FHWA15)

AVCS: Advanced Vehicle Control System  (FHWAII)

Average Fare Per Unlinked Passenger Trip: Passenger revenue divided by unlinked passenger trips.  (APTA1)

Average Fleet Age: The cumulative years active revenue vehicles are in service divided by the sum of all active revenue vehicles.  (FTA1)

Average Flight Stage Length: The average distance covered per aircraft hop in revenue services, from take-off to landing. Derived by dividing the total aircraft miles flown in revenue service by the number of aircraft revenue departures performed.  (BTS6)

Average Length of Haul: (See also Ton Mile) The average distance in miles one ton is carried. Computed by dividing total ton-miles by tons of freight originated.  (AAR1)

Average Lifetime Mileage per Active Vehicle: The cumulative mileage for each active vehicle from the date of manufacture through the end of the fiscal year divided by the number of active vehicles.  (FTA1)

Average Number of Available Seats Per Aircraft: Available seat-miles divided by the number of aircraft revenue miles in passenger service.  (BTS5)   (BTS6)

Average Road Width: The average width of the travelway.  (DOI2)

Average Vehicle Fuel Consumption: A ratio estimate defined as total gallons of fuel consumed by all vehicles, divided by: 1) The total number of vehicles (for average fuel consumption per vehicle) or 2) The total number of households (for average fuel consumption per household).  (DOE4)

Average Vehicle Miles Traveled: A ratio estimate defined as total miles traveled by all vehicles, divided by: 1) the total number of vehicles (for average miles traveled per vehicle); or 2) the total number of households (for average miles traveled per household).  (DOE4)

Average Weekday: A representative weekday in the operation of the transit system computed as the mathematical average of several typical weekdays selected at random throughout the year. A typical weekday is one where there are no anomalies such as high ridership due to extra service added for a convention, or low ridership due to a snowstorm. Average Saturday and Sunday data, including holiday service, are determined the same way.  (FTA1)

AVI: Automated Vehicle Identification  (BTS8)   (FTA4)

Aviation Gasoline: All special grades of gasoline for use in aviation reciprocating engines, as given in the American Society of Testing and Materials (ASTM) Specification D910. Includes all refinery products within the gasoline range that are to be marketed straight or in blends as aviation gasoline without further processing (any refinery operation except mechanical blending). Also included are finished components in the gasoline range which will be used for blending or compounding into aviation gasoline.  (DOE6)

Aviation Gasoline Blending Components: Naphthas that are used for blending or compounding into finished aviation gasoline (e.g., straight-run gasoline, alkylate, and reformate). Excludes oxygenates (alcohols and ethers), butane, and pentanes plus.  (DOE3)

Aviation Mode: Consists of airways and airports; airplanes, helicopters, and other flying craft for carrying passengers and cargo.  (BTS1)   (BTS2)

Aviation Weather Service: A service provided by the National Weather Service (NWS) and Federal Aviation Administration (FAA) which collects and disseminates pertinent weather information for pilots, aircraft operators, and Air Traffic Control (ATC). Available aviation weather reports and forecasts are displayed at each NWS office and FAA Flight Service Station (FSS).  (FAA4)

Aviator: Speeding driver.  (ATA1)

AVIM: Aviation Intermediate Maintenance  (MTMC1)

Avionics: Communications, navigation, flight controls, and displays.  (AIA1)

AVL: Automatic Vehicle Location  (FTA4)

AVLB: Armored Vehicle Launched Bridge  (MTMC1)

AVM: Automatic Vehicle Monitoring  (FTA4)

AVN: Aviation  (MTMC1)

AVO: Available Vehicle Occupancy  (VDOT)

AVS: Aviation Standards  (FAA19)

AWDL: Aviation Weather Development Laboratory  (FAA17)

AWDT: Average Weekday Daily Traffic  (TXDOT)

AWOL: Absent Without Leave

AWOS: Automated Weather Observing Station  (FAA17)   (FAA19)

AWP: Aviation Weather Processor  (FAA19)

AWPG: Aviation Weather Products Generator  (FAA17)   (FAA7)   (FAA19)

AZ: Azimuth  (FAA12)

Azimuth: A magnetic bearing extending from a microwave landing system navigation facility.  (FAA4)