Primary finding
Probable cause
was fuel starvation. A factor in the accident was the mechanic's inadequate inspection of the airplane.
Investigator assessment
Analysis narrative
According to the pilot, during initial climb on the maintenance test flight the airplane gained between 250 and 300 feet altitude when the engine backfired two times and quit. The pilot stated that he turned the airplane to avoid colliding with obstacles and crashed into a plowed wet field. Exam of the airframe and engine did not reveal any mechanical failures. Fuel was found in both fuel tanks and the fuel pumps were found functional. No fuel was found in the carburetor. Prior to the accident flight, the pilot, who was also an A & P mechanic, had performed maintenance on the airplane. The last annual inspection had been completed over seven years earlier, and the airplane had not been flown since that time.
Source record
Factual narrative
On September 30, 1993, at 1648 Pacific daylight time, a Piper PA-28-140, N430FL, experienced a loss of engine power during initial climb from the Lompoc Airport, Lompoc, California. The airplane crashed into a rough, open field adjacent to the airport and was substantially damaged. The private pilot and passenger received minor injuries. Visual meteorological conditions prevailed during the maintenance test flight. According to the Federal Aviation Administration, witnesses reported hearing a "popping noise" during the airplane's takeoff. Thereafter, the airplane stopped gaining altitude. In the pilot's completed "Aircraft Accident Report," NTSB Form 6120.1, he reported that after taking off from runway 25 the airplane climbed between 250 and 300 feet and then "the engine backfired two times and quit." The pilot reported that he turned left to avoid obstacles and crashed into a plowed wet field. The purpose of the flight was to evaluate recently performed maintenance accomplished by the pilot, who also possessed an airframe and powerplant mechanic certificate. The FAA further indicated that the airplane had neither received an annual inspection nor been issued a ferry flight permit. The FAA reported that the examination of the wreckage indicated the flight control system had continuity, there was fuel in both tanks, and oil was present in the engine case. Also, the magnetos produced spark, and the fuel pumps were found functional. The FAA also reported that the tear-down inspection of the engine "did not reveal any internal failure of any components including all accessories." The carburetor fuel inlet screen was found clean, and the "carburetor bowl did not contain any fuel." -