Piper J3C-65 N3666K accident near Huntington Beach, California

Probable cause

A total loss of engine power due to fuel starvation and the pilot’s mismanagement of the available fuel at an altitude too low for recovery. Contributing was the pilot’s delayed decision to switch fuel tanks.

NTSB analysis

The pilot departed the airport on a banner towing operation that would follow the Pacific Ocean shoreline. The airplane carried 36 gallons of fuel in 2 18-gallon fuel tanks and towed a banner. His flight profile was 500 ft agl and about 2,000 ft offshore. The pilot began the flight with the fuel tank selector in the left-tank position. After about 16 minutes of flight, the pilot switched to the right tank and the fuel tank selector remained in the right-tank position for about 2 hours 36 minutes. The pilot reported that shortly after he switched back to the left tank the engine sustained a total loss of power. With little altitude to recover, he elected to land in the water, near the shoreline; the wings and fuselage were substantially damaged in the landing.

On-scene examination of the airplane after recovery from the water revealed that there was no fuel in the right tank. A postaccident examination of the airplane and engine revealed saltwater corrosion on some engine components, but no mechanical malfunctions or failures with the airplane that would have precluded normal operation.

Carburetor ice conditions were calculated to be serious, but only at glide power, which was not the conditions at the time of the total loss of power. Fuel samples taken at the airport’s fuel pump and from the airplane tanks revealed no contamination. A review of maintenance records for the airplane revealed no outstanding anomalies.

Given that the pilot had the right tank selected for about 2 hours 36 minutes, the fuel burn rate was less than estimated by the pilot; however, the discovery that there was no fuel remaining in the right tank and no breaches of the right tank, it is likely the right tank ran empty before the pilot switched to the left tank.

Text from the NTSB. Open the NTSB docket for WPR22LA268 for the full record.