Accident Sequence
Shortly after takeoff, several witnesses reported hearing unusual sounds from the aircraft. One witness stated they heard a sputtering noise followed by the engine stopping, then restarting, though the operation was not smooth. Two other witnesses heard backfiring or sputtering noises. Subsequently, the aircraft entered a steep descent and crashed. Prior to the crash, the pilot transmitted a mayday call and stated that the aircraft was going down.
Investigation Findings
An investigation revealed no evidence of a mechanical problem, with one exception: the left fuel cap O-ring was found to be badly cracked due to age, and the top of the left wing showed signs of fuel streaming, consistent with siphoning.
Preceding Flight Details
Before the accident flight, the aircraft had been flown from Youngstown, Ohio, to Wilkes-Barre, Pennsylvania, and then on to Danbury, Connecticut. The pilot reported that during that trip, he had observed fuel streaming from the left wing throughout the flight and stated that he would see a mechanic about fixing the caps. There was no record of the aircraft being refueled at Wilkes-Barre or Danbury prior to the accident flight. Additionally, a mechanic had previously advised the owner to replace the O-rings.
Conclusion
The investigation did not assign a probable cause in its findings.