Piper PA-22-160 N9547D accident near San Jose, California

Probable cause

A total loss of engine power due to water contamination in the fuel system as a result of the pilot's inadequate preflight inspection.

NTSB analysis

The airplane climbed to about 600 feet above ground level after takeoff and the engine experienced a loss of power. With unfavorable conditions ahead, the pilot opted to turn 180 degrees back toward the airport. The airplane touched down on wet, muddy grass and began to roll onto the asphalt. The airplane nosed over after encountering the lip of the asphalt. A mechanic took fuel samples from the fuel tanks as part of a postimpact inspection. Samples of fuel from the left wing tank, which was selected at the time of the accident, revealed that there was a significant amount of water present. The mechanic opined that the left tank's lower tank panel had possibly bowed up, causing water to be trapped around the sides of the tank. The pilot reported that he did drain fuel from the tanks prior to departure, but that he should have also shaken the wings to induce the trapped water to move down to the sump drains, then rechecked the fuel for contamination.

Text from the NTSB. Open the NTSB docket for WPR10LA083 for the full record.