Aviation Accident Summaries

Aviation Accident Summary ANC19FA021

Wasilla, AK, USA

Aircraft #1

N202AK

Bradshaw / McCauley Giles G-202

Analysis

During the airplane's takeoff roll, two witnesses reported that the engine sounded unusual; the airplane became airborne and flew in ground effect until it reached the end of the runway and then pitched up abruptly. As the airplane reached about 500 feet agl, the engine sputtered and the airplane made a hard-left turn and pitched down. After the loss of engine power, the pilot likely initiated a return to the runway environment, during which the airplane impacted terrain. The airplane was heard regaining power as it descended below the tree line, just prior to impacting the ground. In a postaccident examination, the electric fuel pump was found seized with contaminants inside the internal fuel passages. The contaminants were determined to be consistent with a mixture of fuel additives such as anti-static and anti-corrosion additives. It is likely that, during the takeoff, the electric fuel pump seized due to the fuel contamination and restricted fuel flow to the engine. The engine then experienced a degree of fuel starvation which resulted in reduced engine power.

Factual Information

HISTORY OF FLIGHTOn May 30, 2019, about 1516 Alaska daylight time, an experimental amateur-built Giles G-202 airplane, N202AK, sustained substantial damage when it was involved in an accident in Wasilla, Alaska. The pilot sustained fatal injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. One witness reported that, as the airplane taxied to the approach end of runway 04 at Wasilla Airport (IYS), it appeared that the pilot completed an initial run-up of the engine before takeoff and that the engine sounded strong with no unusual sounds. However, during the takeoff roll, two witnesses stated that the engine sounded unusual. After becoming airborne the airplane remained within ground effect as the speed increased until it passed over the departure end of the runway. Several witnesses reported that the airplane then pitched up abruptly and at about 500 ft agl the engine sputtered. The airplane then made a hard-left turn and pitched down. As the airplane descended it disappeared behind a stand of trees. Two witnesses reported the engine sound increased significantly during the descent and was consistent with a high-power setting. The airplane subsequently impacted a paved roadway near the departure end of runway 04. AIRCRAFT INFORMATIONThe Giles G202 was a single-engine, low-wing, two-seat, aerobatic airplane. It incorporated a tandem flight control arrangement, with the flight control surfaces directly actuated by cables and tubes from the dual cockpit controls. The Federal Aviation Administration issued an experimental category airworthiness certificate for the airplane in May 2000. No logbooks were found or supplied by the family. The family did state that no recent fuel purchases were recorded on the pilot's credit card and that the airplane had been stored for the winter months before the accident. AIRPORT INFORMATIONThe Giles G202 was a single-engine, low-wing, two-seat, aerobatic airplane. It incorporated a tandem flight control arrangement, with the flight control surfaces directly actuated by cables and tubes from the dual cockpit controls. The Federal Aviation Administration issued an experimental category airworthiness certificate for the airplane in May 2000. No logbooks were found or supplied by the family. The family did state that no recent fuel purchases were recorded on the pilot's credit card and that the airplane had been stored for the winter months before the accident. WRECKAGE AND IMPACT INFORMATIONGround scars indicated that the airplane impacted on about a 210° heading, at an elevation of about 332 ft mean sea level (MSL). The composite airplane was heavily fragmented and sustained substantial damage to the fuselage, wings, and empennage. The engine and its components were rotated, and thumb compression was established on all cylinders, in proper firing order. Mechanical continuity was established from the front to the rear of the engine. The rockers and valves all moved in a uniform manner consistent with normal operation. The magnetos were found secured on their respective mounting pads and both magnetos sparked on all leads. No preaccident mechanical failures or malfunctions were noted. The cockpit mounted fuel selector valve was found not placarded, but did select/rotate freely, with the detent firm and proper, and with unobstructed flow during actuation. The gascolator was disassembled and the pleated paper filter had minor sediment found in the bottom of the bowl, with no evidence of water contamination. However, the fuel system was compromised during the accident sequence. The engine driven fuel pump was disassembled with the diaphragm being found intact, the check valves secure, no visible contaminants, and no fuel found inside the pump. The fuel injection servo, fuel flow divider, and fuel injection nozzles were all found, clean with no obstructions or debris, and no evidence of contamination or water. The fuel injection servo diaphragm stack was displaced from the fuel servo body and not observed. The electric fuel pump that was found inline from the gas tanks to the engine-driven fuel pump did not spin freely after being electrically energized and did not operate as designed. The fuel pump cover was removed, and visible contaminations and corrosion were noted in the fuel pump and internal passages, restricting the flow of fuel. The fluid in the fuel pump was tested using a water-finding paste, with no presence of water being detected. The contaminated material found in the fuel pump was sent to the NTSB Materials Laboratory where it was examined using a Fourier Transform Infrared spectrometer; it was determined to be consistent with a mixture of fuel additives. MEDICAL AND PATHOLOGICAL INFORMATIONThe State of Alaska Medical Examiner's Office, Anchorage, Alaska, conducted an autopsy of the pilot. His cause of death was massive deceleration-type traumatic injuries. The FAA's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicology testing on specimens from the pilot, which were negative for drugs and ethanol.

Probable Cause and Findings

The pilot's failure to maintain control after the partial loss of engine power. Contributing to the accident was a contamination of the fuel system, which likely seized the electric fuel pump and restricted fuel flow to the engine.

 

Source: NTSB Aviation Accident Database

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