Amateur-built FLY FISHER N397JL accident near West Glacier, Montana

Probable cause

A total loss of engine power during takeoff due to water contamination in the fuel system. Contributing to the accident was the pilot’s inadequate preflight inspection of the airplane.

NTSB analysis

According to the pilot, during his preflight inspection, he drained fuel from all three fuel drains with no evidence of water noted. During the takeoff roll, the airplane was about halfway down the runway when he heard a small pop and looked at the engine rpm gauge. The pilot stated that he saw no indication of a loss of engine power and decided to continue the takeoff. As the airplane was over the departure end of the runway, the engine lost all power, and the pilot performed a forced landing to an adjacent field. During the landing, the airplane struck trees and came to rest on its right side. The pilot added that when the engine lost power, it was "like it [the engine] had a slug of water." Examination of the recovered engine revealed no mechanical anomalies that would have prevented normal operation. Examination of the airframe fuel filter revealed that a small amount of clear liquid was within the filter bowl. The liquid was tested and found to be water. It is likely that the unusual attitude in which the airplane was parked during the pilot's preflight inspection may have allowed water to be trapped within different areas of the fuel tank that would have prevented the water from gathering at the lowest point within the fuel tank.

Text from the NTSB. Open the NTSB docket for WPR11LA289 for the full record.