SYNOPSIS

On October 16, 1993, at approximately 0631 Alaska daylight time, a wheel equipped Cessna model 207 Stationair airplane, N208SC, registered to and owned and operated by SouthCentral Air, Inc. of Kenai, Alaska, collided with tree covered terrain approximately 34 nautical miles south of Kenai, Alaska. The commercialcertificated pilot, the sole occupant, received fatal injuries and the airplane wasdestroyed. There was no fire and no hazardous cargo was on board the flight. Theflight, a scheduled cargo/mail run conducted under 14 CFR Part 135, departedKenai at about 0613. No flight plan was on file for the flight. Based upon thescheduled time en route, the flight should have arrived in Homer, Alaska at 0700. The accident site is approximately 26 nautical miles north-northwest of Homer.

The National Transportation Safety Board's (NTSB's) Northwest Region FieldOffice in Anchorage, Alaska (NWR-A) was notified of the accident by the FederalAviation Administration's (FAA's) Regional Operations Communication Center(ROC) at 0830 on the morning of October 16, 1993. The NTSB investigator-in-charge visited the accident site on the afternoon of the 16th.

The parties to the investigation were the FAA.

HISTORY OF THE FLIGHT

The pilot-in-command of the accident flight was Daniel Housberg. The pilots wife reported that on the evening of October 15, 1993, she telephoned her husband at approximately 2130 at his apartment in Kenai. She believed that she probably woke him up from the way he sounded when he initially answered the phone. She called just to say hello. She said that they conversed briefly after which she summized that he went back to sleep. She commented that her husband appeared to be in good spirits, that he liked to fly, and that he had never discussed with her any concerns or problems with the airplanes he flew or the company's he flew for.

The pilots flight itinerary for the morning of the 16th called for him to make a scheduled cargo flight from Homer, Alaska to Kenai in N5282U, a Cessna 206. His second flight of the day, the accident flight, was scheduled in N208SC. The schedule required an early morning wake-up and departure from the Homer Airport, the first time he had done so.

At approximately 0340 on the morning of the 16th, a fellow company pilot, Mr. Wesley Ballard, telephoned Mr. Housbergs apartment in Homer. Mr. Ballard stated that Mr. Housberg answered the phone on the second ring and sounded wide awake. The purpose of the call was to inform Mr. Housberg how much cargo weight he could expect for the Homer/Kenai leg and to make sure he flew N5282U so that it could be traded out for N208SC. Their conversation ended with Mr. Housberg asking if N5282U was certified legal for instrument flight to which Mr. Ballard responded that it was.

Mr. Housberg departed Homer in N5282U at approximately 0452. Once airborne, he picked up an instrument flight rules (IFR) clearance to Kenai. His initial assigned en route altitude was 5,000 feet. At 0524, he reported clear of runway 19 at Kenai.

Upon landing in Kenai, Mr. Housberg was assisted by Mr. Ballard in the off loading of cargo from N5282U. Mr. Ballard reported that he observed Mr. Housberg preflight N208SC, ie. shine a flashlight on the plane's tires, drain fuel, and add three quarts of oil to the engine. Mr. Housberg then repositioned N208SC so that the cargo bound for Homer could be placed on board the airplane. Mr. Ballard said that he assisted Mr. Housberg in loading the plane with approximately 530 pounds of mail and about 130 pounds of freight. Mr. Ballard commented that the cargo "about bulked the airplane out but it was loaded well and was not near gross". Mr. Ballard did not know if Mr. Housberg received a weather briefing while he was on the ground in Kenai. Mr. Ballard's final observations of Mr. Housberg were that, "he seemed in good spirits and did not seem tired at all". Just before they parted company, Mr. Housberg commented that he had to get going so he could get the mail to Homer in time for it to get to the post office by 0700.

Mr. Housberg departed Kenai for Homer in N208SC at approximately 0611. No record of the plane's weight and balance was left behind nor was one required to under present 14 CFR Part 135 regulations. The amount of fuel on board was not recorded. The pilot who last flew the airplane on October 15, 1993, reported that the plane had about 3 1/2 hours of fuel on board.

The first and only known intra-cockpit communication with N208SC occurred at about 0614 when Mr. Housberg made a radio call to the Kenai Automated Flight Service Station (AFSS) requesting the Homer weather. Mr. Housberg was given the 0550 Kenai surface weather observation (SA) which was: measured ceiling two thousand one hundred broken, two thousand eight hundred broken, visibility one two, temperature four three, dew point three six, wind two three zero at eight, altimeter two niner four eight.

From 06:11:38 to 06:31:16, the Air Route Traffic Control Center Radar Site (ARTCC) at Kenai tracked the 1200 transponder beacon code of N208SC. The radar site is approximately 34 miles south of the accident site. Air traffic personnel reported that the horizontal tolerance of the radar is 1/4 mile up to a distance of 200 miles, the altitude data is recorded to the nearest 100 feet, and the ground speed data is "very accurate". The radar data shows that the ground track of the airplane to be south southeasterly from right to left of V (Victor) Airway 435. V435 is a radial between the Kenai VOR (163 outbound) and the Homer VOR 344 radial (164 inbound). The airway is the shortest distance between Kenai and Homer (55 nautical miles) and is used by SouthCentral to compute the flight time schedule between the two points. The minimum en route altitude (MEA) and minimum obstruction clearance altitude (MOCA) on the airway is 2000 feet for the first 20 nautical miles outbound on the Kenai 163 radial and 4400 feet the last 35 nautical miles on the Homer 344 radial. The accident site intersects the Kenai 157 radial.

During the last 10 minutes of recorded radar data, the altitude of the flight varied from 2,000 to 2,200 feet and the ground speed from 109 knots to 124 knots. The last recorded altitude,heading, and ground speed of the airplane was 2,000 feet at 06:30:40, 172 degrees at 06:31:16, and 118 knots also at 06:31:16. The accident site is approximately 4 1/2 nautical miles east of Victor 435.

At approximately 06:40 on the morning of October 16, 1993, Mr. James Matti heard an airplane flying overhead near his cabin. The plane's engine emitted a steady drone and there were no missing or sputtering sounds. As the sound from the engine began to fade, he heard a loud crashing noise. The sound from the engine stopped altogether and it sounded like there was another crash. He thought about calling 911 but was not sure that an accident had occurred until later in the morning when he observed other airplanes and a helicopter in the air. Mr. Matti said that he lives approximately 1/2 miles west of the high tension power lines that run between Kenai and Homer (officially known as the Soldotna to Fritzcreek to Bradley Lake 115KV transmission lines) and that from what he was told by the Alaska State Troopers, the aircraft crashed approximately 2 to 3 miles from his cabin. The accident site is about 200 yards east of the power lines. When he heard the airplane, the sky in the area around him was clear and he could see the stars.

DAMAGE TO AIRCRAFT

The airplane sustained extreme structural deformation from shear and crushing forces.

OTHER DAMAGE

The tops, mid span, and trunk surfaces of several trees were severely damaged or destroyed.

PERSONNEL INFORMATION

The pilot-in-command, Mr, Daniel Housberg, dob May 16, 1957, possessed commercial pilot certificate No. 052387598, latest issue date December 12,1990, for airplane single engine and multi-engine land with instrument privileges. He also possessed a flight instructor certificate, latest date August 31, 1993, for airplane single engine/instrument airplane. His first class medical certificate, dated June 14, 1993, contained the requirement for wearing lenses which corrected for distant vision. He also possessed a statement of demonstrated ability, waiver #10D79315, dated 07/20/93, for defective distant vision.

Mr. Housberg was initially employed by SouthCentral Air, Inc. as a line pilot in their single engine Cessna airplanes on July 01, 1993. He provided the airline with a resume of his aeronautical experience, dated June 23, 1993, which indicated the following: total flight time: 1,250 hours, pilot-in-command: 1,180 hours, Alaska time: 979 hours, actual instrument: 28 hours, simulated instrument: 174 hours, multi-engine: 96 hours, single-engine: 1,154 hours, night: 86 hours, cross country: 652 hours, CFI 300 hours.

Training records provided by SouthCentral Air, Inc. indicate that Mr. Housberg received initial ground training from July 01, 1993 through July 03, 1993. The number of hours involved was not stipulated. The records indicate that from July 05, 1993 through July 08, 1993, he received 8.1 hours of flight training all of which were accrued in the Cessna 207 aircraft, specifically N208SC. On July 09, 1993, he received 1.9 hours of flight training then completed a 14 CFR Part 135 airman competency/proficiency check of 1.7 hours duration in N208SC. The check was administered by the company's director of operations. Airman competency information on the check ride form indicated that Mr. Housberg demonstrated current knowledge of FAR - 135.293(a), demonstrated competency FAR 135.293(b), satisfactory demonstrated line checks - FAR 135.299, and demonstrated IFR proficiency - FAR 135.297. The flight training record indicates that he received 7 hours of initial route qualification from July 12, 1993 through July 14, 1993, of which 1.6 hours were in N208SC. His pilot duty sheet for the month of July 1993 indicated that from July 15 he flew 40.6 hours. His flight times for the months of August and September 1993 were 83.2 hours and 100.4 hours, respectively. His pilot duty log sheets for the month of October 1993 revealed the following:

Date Time Out Time In 10/10/93 Day Off 10/11/93 Day Off 10/12/93 1102 1930 10/13/93 1105 1922 10/14/93 1207 1542 10/15/93 0845 1250 10/16/93 0445

The pilots wife told the NTSB investigator-in-charge that when her husband was not flying for the airline, he spent his off days around their home located near Anchorage, Alaska. She said that he would routinely go to bed between 11pm and 12 midnight and that he would sleep in to somewhere between 9am and 11 am the next morning. She said that her husband was definitely not a morning person and that on several occasions he had commented to her that the quality of his sleep was poor.

Mr. Housberg did not fill out an inhouse/company VFR flight plan for the Kenai/Homer flight as required by SouthCentral operations procedures. As far as could be determined, this was the first occasion that he had not done so.

The FAA's Airmen Data files contained no previous accident/incident or enforcement activity on the pilot.

James A. Munson, Director of Maintenance for SouthCentral told the NTSB investigator-in-charge during the field phase of the investigation that Mr. Housberg was known to fly a route along the electric power lines between Kenai and Homer and that it was by following the power lines that company personnel located the downed airplane on the morning of the 16th. The altitude at which Mr. Housberg flew this routing was not known. SouthCentral pilots familiar with the powerline routing reported that an aircraft would be skimming the treetops at 2600 feet.

The Seward, Alaska Sectional Aeronautical Chart (scale 1:500,000), when use in conjunction with the 115KV transmission line map provided by Homer Electric, shows the altitude of the terrain along the power line in the general area of the accident to be approximately 1950 feet msl.

AIRCRAFT INFORMATION

The airplane, a 1978 Cessna model 207A Stationair, registration N208SC, serial number 20700445, was authorized operations under a Standard Air Worthiness Certificate. The airplane was powered by a Teledyne Continental IO-520DCF engine turning a McCauley propeller. The airplane had a maximum takeoff and landing weight of 3,800 pounds.

SouthCentrals FAA accepted Operations Specifications authorized the Cessna 207A airplane for cargo only day/night IFR/VFR en route operations.

The airframe, engine and propeller were inspected under an FAA approved aircraft inspection program at 50 hour intervals. The airplane was last inspected on October 06, 1993. At the time of the accident, the total airframe hours, engine hours, and propeller hours were 9,067, 1,587.1, and 1,467, respectively.

The service bulletin & airworthiness directive compliance record indicated that all of the applicable airworthiness directives (AD's) had been complied with.

The altimeter on board the airplane was a United Instrument model A-78, part no. 5934PA-1, serial no. H3981. The altimeter was last tested on March 29, 1993. The altimeter scale error at 2,000 feet was five feet. The latest test and inspection of the static pressure system occurred on September 04, 1993.

The aircraft maintenance binder for N208SC was recovered from the accident site. The maintenance binder provides the flight crew with a quick reference as to the general condition of the airplane and the status of the required inspections. The airworthiness inspection page indicated that next check of the altimeter/static system was due in January 1994. The VOR Check Log page indicated that the most recent operational check of the No. 1 and No. 2 VOR navigation receivers occurred on September 22, 1993. The check was conducted at the ground based VOT test sight at the Anchorage International Airport. The TO/FROM bearing error between the two receivers was + - 1 degree.

The latest weight and weight and balance equipment list page was compiled and computed on 11/06/87. The computed empty weight of the airplane was 2164.4 pounds resulting in a useful load of 1635.6 pounds. A review of the aircraft maintenance log pages disclosed that there were no open maintenance writeups.

The last person to fly N208SC prior to Mr. Housberg was SouthCentral line pilot John Mahany. Mr. Mahany was interviewed over the telephone and also provided a statement concerning his observations of N208SC. Mr. Mahany stated that he last flew N208SC on October 15, 1993, and that everything worked well in the airplane. There were no open write ups. Because the weather was so good, he did not rely heavily on the VOR navigation equipment, but they displayed normal indications. There was not much precession in the directional gyro, perhaps 5 degrees per hour at the outer limit. The altimeter, when adjusted for barometric pressure was right on the field elevation.

Another SouthCentral line pilot, Wesley Ballard, reported that he last flew N208SC on October 14, 1993. As he recalled, the airplane seemed to handle well. The VOR checks which he performed in the aircraft during previous flights were well within the limits. The altimeter was very close, reading only about 25 feet low. The directional gyro precessed very little, perhaps 5 to 10 degrees between Kenai and Homer.

ATMOSPHERIC AND METEOROLOGICAL INFORMATION

Sunrise-Sunset data corrected for an altitude of 1,750 ft. msl for the accident location, time, and date revealed that the start of twilight occurred at 0659 with sunrise occurring at 0742. On October 16, 1993, moon rise and moon set occurred at 1115 and 1852, respectively. The National Weather Service reported that there was little or no moon phase at night.

The first search aircraft arrived in the area of the accident site at approximately 0845 and reported encountering scattered stratus clouds at 1,000 feet agl and patchy fog.

The recorded Surface Weather Observations for Kenai, Alaska (ENA) were:

0546 - 1,100 feet scattered, estimated ceiling 5,000 feet broken, 6,500 feet overcast; visibility 15 miles; temperature 40 degrees F; dew point 39 degrees F; winds 180 degrees at 7 knots; altimeter setting 29.45 inches of Hg.; breaks in the overcast.

0646 - 1,200 feet scattered, 5,000 feet scattered; visibility 20 miles; temperature 40 degrees F; dew point 39 degrees F; winds 170 degrees at 7 knots; altimeter setting 29.43 inches of Hg.

The recorded Surface Weather Observations for Homer, Alaska (HOM) were:

0550 special - Measured ceiling 2,100 feet broken, 2,800 feet broken; visibility 12 miles; temperature 43 degrees F; dew point 36 degrees F; winds 230 degrees at 8 knots; altimeter setting 29.48 inches of Hg.

0652 special - 2,300 feet scattered; visibility 12 miles; temperature 42 degrees F; dew point 36 degrees F; winds 220 degrees at 13 knots; altimeter setting 29.47 inches of Hg.

(NOTE. For Additional Details, See The Attached Meteorological Factual Report).

AIDS TO NAVIGATION

Federal Aviation Administration Airways Facility records for the Kenai and Homer VORs were reviewed for the month of October 1993. The records indicated that the VORs operated within established tolerances during this period. During the course of the investigation, there was no information that came forth that suggested that the Kenai and Homer VORs operated in other than a satisfactory manner during the period in which the accident occurred.

On October 16, 1993, there were no NOTAMS pertinent to the Kenai or Homer VOR facilities.

COMMUNICATIONS

There were no known communication difficulties experienced with ground or airborne equipment.

WRECKAGE AND IMPACT INFORMATION

The accident site was in an area of forested hills at an elevation of approximately 1,950 ft. msl. The global positioning system (GPS) coordinates of the accident are 60'02.51N by 151'13.08W. The area of the crash site was 450 feet long by 75 feet wide. The airplane initially struck an evergreen tree approximately 80 feet in height by 20 inches in diameter. The initial impact heading was 135 degrees magnetic. The left wing support strut and inboard fragments of the left wing and the left wing tip fiberglass shroud were found about 15 feet south of the tree. The main wreckage area was located about 400 feet from the initial impact point near the base of a tree and consisted of the right wing minus the flap, the cockpit, and the empennage.

The flight path angle between the initial tree strike and the main wreckage site was approximately 40 degrees.

There was no evidence of a fire at the site. All of the major structural components and flight control surfaces were accounted for at the site. The flight control cables, bellcranks, and pulleys exhibited failures due to tension overload.

A McCauley three bladed propeller, SN 861474, was found about 15 feet northwest of the main wreckage site and was separated from the engine crankshaft flange. The propeller to crankshaft flange bolts were sheared. The propeller blades remained attached to the propeller governor hub. The propeller governor hub was covered with oil smears and residue. Each of the propeller blades rotated freely about its base attachment point at the hub. Each blade exhibited slight rearward bending from its normal plane of rotation. The leading edges of the three blades exhibited abrasion and scoring signatures along their entire span.

The engine assembly, a Teledyne Continental IO520DCF, SN566110, was found approximately 20 feet east of the propeller or about 35 feet northeast of the main wreckage area. The engine case remained intact. All crankshaft, piston, and valve train components were accounted for. The engine oil pan was punctured. Pieces of tree bark and pine needles were found inside the oil pan. The crankshaft, piston connecting rods and valve train components were bathed in oil. The engine oil filter and screen were examined and found to be free of contaminants. The spark plug electrodes exhibited a slight grayish appearance. The vacuum pump and the left and right magneto housings were bent, fractured, and/or punctured.

The cockpit cabin, including the flight and navigation instrument panel sustained gross deformation. All of the flight and navigation instruments were damaged to varying degrees and were scattered throughout the main wreckage area.

The airspeed indicator registered zero. The indicators glass face was cracked and its metal facing and case were dented.

When the indicator was picked up for examination, internal components could be heard moving about in the case.

The attitude indicator (artificial horizon) displayed a nose up attitude of two to three degrees. Its glass face was shattered, and its metal facing and case were dented. When picked up for closer examination, internal components could be heard moving about in the case. The directional gyro indicated 305 degrees. The glass face was intact as was the adjusting arm.

The magnetic compass was not located.

The altimeter was found lying on top of what remained of the dash and was loosely attached to a portion of the instrument panel. The altimeter read 240 feet and the setting window read 29.50. When the setting knob was rotated, there was coinciding movement in the setting window and movement of the elevation needles. The glass face was intact. The static tube was torn from the back of the case. The case was dented along its sides and back. When picked up for closer examination, an internal component could be heard moving about in the case.

The engine performance and monitoring gauges were also examined. The fuel selector was on the right tank and the selectors cam was broken. The throttle, propeller, and mixture controls were full in. The oil pressure indicator was in the green (normal) range. The engine manifold pressure gauge indicated 27 inches. The fuel gauges read zero. The flap handle was found in the up (flaps retracted) position.

The Com 1 radio and Com 2 radio channel selectors read 123.65 mhz. and l31.60 mhz., respectively. Neither frequency is associated with the Kenai or Homer airports. The channel selectors for the Nav 1 and Nav 2 receivers were set to the Homer VORTAC frequency of 114.60 mhz. The faces of both Nav receivers were liberated from their mounting points.

The Emergency Locator Transmitter (ELT) was found in the rear of the plane. The ELT was loose from its mounting point and its case was cracked. The ELT switch was in the armed position. A scan of the emergency 121.5 mhz. from overhead the accident site revealed that no transmission was forthcoming from the ELT.

(NOTE. For Additional Information, See The Attached Wreckage Distribution Diagram)

MEDICAL AND PATHOLOGICAL INFORMATION

The autopsy was performed in Anchorage, Alaska. by Dr. Michael T. Propst, a Forensic Pathologist. The autopsy report revealed that the pilot-in-command succumbed to impact injuries received in the accident. Toxicology was negative.

TEST AND RESEARCH

The National Aeronautics And Space Administration's (NASA's) Flight Human Factors Branch at the Ames Research Center has conducted scientific research on basic human physiology as it pertains to sleep and circadian rhythms. The research has demonstrated that sleep is a vital physiological function. When deprived of this physical need the brain becomes sleepy and physiological sleepiness can result in major decrements in essentially all areas of human performance. As little as one hour less sleep than is usually required by an individual can lead to decreases in waking performance and alertness. Two hours less sleep than is usually required by an individual can create major degradations in these areas during wakefulness. Research has demonstrated that with increasing sleepiness, individuals demonstrate poorer performance despite increased effort, and report an indifference regarding the outcome of their performance. While an individual may not actually fall asleep, the level of sleepiness can significantly degrade human performance. For example, the individual may react slowly to information, may incorrectly process the importance of the information, may find decision making difficult, may make poor decisions, and may have to check and recheck information or activities because of memory difficulties.

Scientific research has also demonstrated that individuals are typically very poor at objectively evaluating their alertness and performance. A sleepy individual's self-report that they are alert and performing well would be expected often to be highly inaccurate and not reflect degraded performance or alertness. An evaluation by ones peers is also apt to be highly subjective.