Mooney M20J N66201 accident near Kapolei, Hawaii

Probable cause

Loss of engine power due to water in the fuel lines.

NTSB analysis

The certified flight instructor (CFI) reported that, during the pre-flight, a small amount of water was drained from the left fuel tank; no water was noted in the sample from the right tank. Following the departure on the instructional flight, the CFI and the pilot receiving instruction conducted several maneuvers before practicing touch-and-go landings; fuel tanks were regularly switched throughout the flight. During the sixth takeoff, with the landing gear and flaps retracted, at about 300 ft above ground level, the engine lost power. The CFI took control of the airplane, switched fuel tanks, and attempted to troubleshoot the engine, but he was unsuccessful. He initiated a forced landing to the runway with the landing gear in the UP position to avoid rolling into unknown grassy terrain.

During the postaccident examination, some water was drained from the left fuel tank. The right fuel tank was free of water. The fuel collected from the fuel line going into the fuel injectors also contained some water. The propeller was rotated manually, and the continuity was established throughout the engine. No mechanical issues with the engine were noted at the time. It is likely the engine lost power due to water in the fuel.

Text from the NTSB. Open the NTSB docket for WPR18LA280 for the full record.