What happened
The pilot reported that shortly after takeoff, at approximately 500 feet above ground level, the engine lost power. In an effort to restore engine operation, the pilot activated the electric fuel pump. This action was unsuccessful in resolving the issue. Consequently, the pilot elected to land the aircraft immediately. During the landing attempt, the aircraft collided with trees and subsequently fell to the ground before coming to rest.
The investigation
A post-crash inspection of the aircraft revealed that the fuel tanks contained approximately 40 gallons of fuel. Of this total volume, 30 gallons were identified as automotive fuel. According to published Federal Aviation Administration (FAA) information, the use of automotive fuel in aircraft engines may cause vapor lock. A post-crash run-up of the engine revealed no evidence of pre-impact failure or mechanical malfunction.
Findings
The investigation determined that the engine lost power due to the ingestion of automotive fuel, which likely caused vapor lock. The pilot's attempt to use the electric fuel pump did not restore sufficient power for safe flight, leading to a forced landing into terrain. The engine itself showed no signs of pre-existing mechanical defects.
Safety message
Pilots must ensure that only approved aviation-grade fuel is used in aircraft engines. The use of automotive fuel can lead to vapor lock and subsequent engine failure, posing a significant safety risk during critical phases of flight.