NTSB Factual Report

1.1 HISTORY OF FLIGHT

On January 17, 1994, at approximately 1130 Alaska standard time, a wheel/ski equipped Piper PA18-160 airplane, N6574L, registered to and operated by the pilot-in-command, crashed on a glaciated snow bridge at the 5100 foot level of the Matanuska Glacier following a loss of engine power. The coordinates of the accident site are North 61.34.99 - West 147.28.61. The nearest populated settlement to the site is Palmer, Alaska, located approximately 45 nautical miles to the east. The pleasure flight, conducted under 14 CFR Part 91, departed the glacier about one minute prior to the accident and the intended destination was the Lake Hood Airstrip in Anchorage, Alaska, situated about 90 nautical miles to the southwest, where the flight originated on January 15, 1994. The surviving passenger reported high ceilings and good visibility with light winds and no turbulence were present in the area at the time of the accident. There was no VFR flight plan on file for the flight.

1.2 INJURIES TO PERSONS

Fatal: Pilot Serious: Passenger

1.3 DAMAGE TO AIRCRAFT

The airplane was destroyed from the impact with the snow and ice covered terrain.

1.4 OTHER DAMAGE

None.

1.5 PERSONNEL INFORMATION

PILOT

Kevin Byron Park, date of birth March 22, 1956, was the holder of private pilot certificate No. 574321888, latest issue date April 9, 1992, with the privileges and limitations of airplane single engine land, instrument. His third class medical certificate, issued on January 13, 1993, and contained the limitation, "must wear corrective lenses". Mr. Parks indicated on the application for his medical that his total civilian flight hours was 1100.

The pilot's immediate family provided the NTSB with two personal flight time logs which bore his name. The flight logs covered the period July 13, 1976 thru August 12, 1992. The logs contained entries for Cessna 150, Mooney M20F, and Piper PA18 aircraft. Total combined flight time recorded in the logs was 949.9 hours. The first recorded entry of a flight made in a PA18 aircraft, which also occurred in N6574L, was July 25, 1992. The pilot's total recorded flight time in N6574L was 8.9 hours covering the period July 25 thru August 12, 1994. Additional entries recorded in the logs included a date of July 1992 which indicated that a flight instructor had found him competent to act as pilot-in-command of tail-wheel airplanes. Mr. Park's family advised the NTSB that he was known to record his flight time in a small yellow notebook. The whereabouts of the notebook is unknown. Mr. Parks also owned a Cessna 206. Another flight instructor in the Anchorage area reported to the NTSB that in June of 1993 he gave Mr. Parks a Biannual flight review (BFR) in N6574L and that the review included slow flight and stalls.

No record was found of Mr. Parks recent flight experience. Unofficial accounts from friends and acquaintances indicate that he would try to fly at least once a week or as often as his job as an emergency room physician would allow.

PASSENGER INFORMATION

On the afternoon of January 19, 1994, the passenger on board N6474L, Mr. Richard Baranow, a 36 year old male from Anchorage, Alaska, was interview at Providence Hospital by the NTSB investigator-in-charge. Also present at the interview were the passengers brother, and Mr. Lee Allen of the FAA. The following information was provided by Mr. Baranow.

He is a chemist by profession and does not possess a pilot certificate. His flying experience with Mr. Parks consisted of four or five previous flights. The two of them departed the Lake Hood Airstrip in Anchorage, Alaska on Saturday afternoon, January 15, 1994, for the purpose of flying to and landing on the Matanuska Glacier to climb nearby mountains. They landed on the glacier between 1300 and 1400 at a site that was about one fourth of a mile down from the climbers hut. They unloaded their gear and Mr. Parks performed three touch and go landings on the glacier. Afterwards, Mr. Parks placed a cover around the engine cowling. No wing covers were placed over the wings and he did not recall seeing any covers inside the airplane. The decision was made on Sunday night, January 16, 1994, to get up early on Monday morning and return to Anchorge because Mr. Parks had to be at work at 12 o'clock noon. The two of them got to bed around one a.m. and awoke at around seven a.m. Mr. Baranow characterized the weather on the glacier on Monday morning as a pretty day with a somewhat clear sky and calm wind. He observed Mr. Parks remove the engine cowl blanked and the light dusting of snow from the plane's exterior surfaces and drain fuel from the plane's left and right fuel wing tanks and the engine fuel sump. Prior to starting the engine, Mr. Parks used a gas powered engine heater for approximately 50 minutes to warm the engine. Afterwards, the engine was run for approximately five minutes then shutdown and Mr. Baranow boarded the back seat of the plane. The engine was restarted and run for about two minutes before the takeoff was commenced. The engine sounded fine while he was outside the airplane but sounded a bit different when seated inside. From inside he characterized the engine sounding similar to an automobile engine shortly after being started on a cold morning. He advised Mr. Parks of his observations. Mr. Parks told him that the sounds emitted by the engine as well as the engine instrument indications were normal. He did not recall the position of the flaps. The takeoff from the glacier was made to the north and the takeoff run and initial climb out were uneventful. After the plane became airborne, Mr. Parks made a shallow climbing turn to the left, not quite a 180 degrees change in direction from the initial takeoff heading. Approximately one minute after departing the glacier, while in a normal climbing attitude, Mr. Parks made a shallow banking turn to the left and was in the process of making a similar turn to the right when the engine suddenly lost power without warning. At the time, the plane was approximately 200 feet above the ground. He was not aware of the plane's indicated airspeed but felt it was slow and at or close to what he was accustomed to sensing on previous flights with the pilot. After the engine lost power, it may have sputtered once. No unusual loud and/or metallic sounds were emitted by the engine either prior to or after power interruption. Almost immediately afterward, the airplane fell like a rock. He had the feeling that the airplane pitched down rather abruptly and banked to the right before colliding with the ground. He was rescued by pararescue personnel at about 1130 on January 18, 1994.

1.6 AIRCRAFT INFORMATION Airplane N6574L, having serial number 18-7409106, was manufactured in 1974 under the standard/normal certification process. The airplane was registered to Kevin B. Parks on August 10, 1992. The maximum certificated gross takeoff weight of the airplane was 1750 pounds. FAA records indicate that the airplane had no previous accident/incident history. At the time of the accident, the total hours on the airframe was 1766.

Fuel records indicated that prior to the flight's departure to the glacier on January 15, 1994, the plane's wing tanks were topped off with 28 gallons of 100LL aviation gasoline resulting in a total of 36 gallons of wing fuel distributed evenly in the plane's two wing tanks. No fuel was added to the belly tank and it is not known if this vessel contained any fuel prior to the flight's departure from Anchorage. The contract fueler reported that at the completion of the fueling operation both fuel caps were on and secured to their respective tanks.

The actual all up operating weight of the airplane at the time of the accident is not known. Both fuel tanks were ruptured and much of the cargo in the form of winter clothing was saturated with water and fuel.

The plane was equipped with a Textron Lycoming O-320-A2A engine, SN: L-49772-27A, that had been STC'd to the 160 hp conversion. The engine was overhauled to zero time in July 1992, and at the time of the accident had accrued 168 hours.

The airframe, engine, and propeller received their most recent annual inspection in July 1993. Maintenance records indicated that all applicable AD's had been complied with and that their were no outstanding discrepancies or reoccurring problems with the plane's structure, powerplant, or systems.

1.7 METEOROLOGICAL INFORMATION

The nearest weather reporting facility to the accident site was Tahneta Pass located approximately 24 statute miles northeast of the accident site. The 1145 AST record observation for Tahneta Pass on January 17, 1994 was 900 scattered, estimated ceiling 2500 broken, 6000 overcast, visibility 15 statute miles, temperature 3 degrees fahrenheit, dew point -1 degree fahrenheit, wind 360 degrees magnetic at 10 knots, altimeter setting 29.46.

1.8 WRECKAGE AND IMPACT INFORMATION

FOREWORD The NTSB investigator-in-charge (IIC) visited the accident site on January 24, 1994. The IIC was accompanied by an airplane mechanic who was learned in the skills of glacier travel and winter survival. Because the wreckage was located on a snow bridge, all work performed at the site was conducted under belay and/or by tether using the transport helicopter as an anchor source.

KINEMATICS The plane impacted on a snow bridge joining a crevasse of unknown depth. The bridge was roughly 10 feet below the crest of the crevasse. The plane was found inverted on the bridge. The impact angle was measure at 52 degrees and the heading at 315 magnetic. The initial impact sequence was the right wing followed by the nose of the aircraft, and the left wing.

STRUCTURE With the exception of the left wing fuel cap, all major structural components were accounted for at the site. Continuity was established with the flight controls. Fractures of the flight control cables were a result of mechanical cutting or tension overload. The wings remained partially attached to the fuselage and the struts. The left wing exhibited very little vertical or horizontal bending. The right wing was found bent near vertically and about 78 degrees aft from its normal horizontal plane. Both wings exhibited little deformation along their leading edges. The flaps moved freely and beyond their normal limit of travel. Both wing mounted fuel tanks were ruptured. An odor of fuel permeated the surrounding area near each of the respective tanks. The fiberglass belly fuel tank was cracked but intact. Their was no strong odor of fuel present in the tank. Beginning just aft of the passenger compartment, the fuselage was bent vertically upwards approximately 60 degrees. The horizontal stabilizer and elevator displayed little physical damage. The vertical stabilizer exhibited compression deformation.

ENGINE/PROPELLER Most of the engine and half of the propeller were buried in the snow and had to be dug out for viewing purposes. The engine assembly moved rearward and penetrated the flightcrew compartment by approximately 8 to 10 inches. The propeller exhibited very slight damage along the leading edge of the blades. No blade queing and/or twisting was present. The blades exhibited aft bending of 5 degrees and 40 degrees, respectively.

COCKPIT The pilots seat had come loose from its attachment points. However, the lap belt and shoulder harness were intact. The passengers seat attachment points, lap belt and shoulder harness remained intact. The fuel tank selector knob was bent and stuck between the off and right tank positions. The engine push/pull control cables were either bent or broken from their respective connections. The throttle control was at idle, the mixture full rich, and the carburetor heat was in. The airspeed and RPM gauges indicated zero. The oil pressure gauge indicated 75 PSI. The flap handle was found in the zero flap position.

1.9 MEDICAL AND PATHOLOGICAL INFORMATION The cause of death for the pilot was determined by the State of Alaska, Office of the Medical Examiner to be directly related to injuries sustained in the accident. Toxicological testing on tissue samples obtained posthumously from the pilot were negative for alcohol, major drugs of abuse, and prescription and over the counter medications.

1.10 TEST AND RESEARCH

The aircraft was removed from the glacier by helicopter and transported by truck to Anchorage, Alaska for a more extensive inspection.

The results of the examination included the following observations: The carburetor was torn from its engine mounting plate. The carburetor filter screen was clean. The gasolator was punctured and bent, the filter was clean, the lines were attached and the hoses were not damaged. The fuel primer lines were attached. The automotive electrical fuel pump used to uplift fuel from the belly tank to the left wing tank was run and produced suction. The No. 1 cylinder valve lifter rod tube shroud was bent and restricted movement of the valve train. The valve covers were pulled. The valve components were bathed in oil. The oil screen was clean and the oil pan free of debris. The oil cooler was ruptured. The crankshaft flange was bent 1 1/4 inches out of round. With the aid of a breaker bar, the engine was turned over 360 degrees and revealed continuity between the valve, piston and accessory components. The flywheel was not burred and the gear teeth were not defaced. The internal baffling of the muffler was intact and displayed no visible signs of deterioration. The left and right magneto's were not damaged and produced a spark. The magneto ground "P" leads were cut. Many of the spark plug cable wires were cut. The spark plugs displayed a light frosty gray color.

NTSB Probable Cause

LOSS OF ENGINE POWER FOR UNDETERMINED REASONS. A FACTOR IN THE SEVERITY OF THE ACCIDENT WAS THE FAILURE OF THE PILOT-IN-COMMAND TO MAINTAIN CONTROL OF THE AIRPLANE WHEN THE ENGINE CEASED PRODUCING POWER.