What happened
The pilot had previously flown to the airport to perform radio work. While the aircraft was parked on the ramp for two hours, the area experienced hard rain. Following this period, the aircraft was taxied to the FBO and refueled. During the subsequent takeoff roll, witnesses heard the left engine sputtering. As the airplane became airborne, it veered toward the left, stalled, and impacted the ground. The pilot was not injured.
The investigation
Investigators examined the refueling truck and found no water present; other aircraft had been fueled from the same truck both before and after the accident without any reported discrepancies. However, a post-accident examination of the aircraft revealed water in both engine fuel pumps.
Regarding the fuel system components, the thermos-type fuel caps on both main tanks were found to be loose, and the seals were cracked. While an Airworthiness Directive (AD) requires these fuel caps to be inspected annually, the aircraft logs indicated that the most recent inspection had been completed approximately one month prior to the accident.