Mooney M20J N4826H accident near Allentown, Pennsylvania

Probable cause

A total loss of engine power during takeoff due to an interruption of fuel flow to the engine. The reason for the interruption of the fuel flow could not be determined during postaccident examination and testing.

NTSB analysis

The pilot stated that he departed with about 25 gallons of fuel in the left wing fuel tank and about 7 or 8 gallons in the right wing fuel tank and with the fuel selector positioned to the left wing fuel tank. After departure, he flew the airplane to a local airport to practice takeoffs and landings. During the fourth takeoff, about 30 minutes into the flight, and when the airplane was about 400 to 500 ft above the runway, the engine suddenly stopped producing power. The pilot made a forced landing straight ahead, and the airplane struck a fence.

Postaccident examination revealed no mechanical anomalies that would have precluded normal engine operation. Examination of the airplane revealed that the left and right wings were damaged, but no fuel was observed leaking from the airplane. About 4 to 5 gallons of fuel was found in the right tank, and about 8 to 12 gallons of fuel was found in the left tank; the fuel found in the tanks was higher than the unusable fuel limit for each tank. The fuel line from the engine-driven fuel pump to the fuel servo was disassembled, and there was no fuel in the line. The fuel line from the boost pump to the engine-driven fuel pump was disconnected, and, when the boost pump was turned, fuel came out in a pulsating spray, which indicates that air was in the line. Based on the evidence, it is likely that there was an interruption of fuel flow to the engine, which resulted in the loss of power; however, the reason for the interruption of the fuel flow could not be determined.

Text from the NTSB. Open the NTSB docket for ERA15LA177 for the full record.