Piper PA 28R-200 N9431N accident near St. Augustine, Florida

Probable cause

A total loss of engine power for reasons that could not be determined because examination of the airplane and engine did not reveal evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation and because the amount of fuel onboard the airplane could not be verified.

NTSB analysis

The flight instructor reported that, during a training flight to practice touch-and-go landings, while the airplane was climbing through 500 ft, the engine started to "sputter." The student pilot, who was flying the airplane, stated that she switched the fuel tanks just before the engine lost power but that she was unsure which tank she had selected. Due to the low altitude, the flight instructor took control of the airplane and performed an emergency landing in a marsh, during which the right wing and airframe sustained substantial damage.

An examination of the airplane and engine did not reveal evidence any preimpact mechanical malfunctions or failures that would have precluded normal operation. Before takeoff, the airplane had 25 gallons of fuel onboard, and the airplane had been flown about 1 hour before the engine lost power. According to the engine operating manual, the engine's fuel consumption rate was 12.5 gallons per hour, which would have resulted in about half of the fuel supply still being available when the engine lost power, assuming that the supply of fuel in the selected fuel tank had not already been exhausted. However, the postaccident quantity of fuel onboard the airplane could not be verified due to the airplane having rested in the marsh after the accident. Therefore, based on the available evidence, the reason for the loss of engine power could not be determined.

Text from the NTSB. Open the NTSB docket for ERA17LA300 for the full record.