Amateur-built COZY Mark III N964AL accident near Mcdermitt, Oregon

Probable cause

The pilot's inadequate preflight fuel planning, which resulted in a total loss of engine power due to fuel exhaustion.

NTSB analysis

According to the pilot, he had recently purchased the airplane and was in the process of relocating it to his home airport. During the flight, he had no way to monitor the fuel burn during the flight other than the fuel sight gauges, which he could not see due to objects blocking his view. While the pilot was not able to monitor the fuel burn during the flight, he did lean the fuel and routinely switched fuel tanks; he believed he had plenty of fuel for the flight. After flying for about 2 hours and 20 minutes, the airplane sustained a complete loss of engine power. Unable to maintain altitude, he conducted an off-airport landing to a dirt road. During the landing roll, the airplane encountered uneven terrain, nosed over, and came to rest inverted.

A visual inspection of the fuel system was conducted, and continuity was established from the main fuel tanks throughout the system; however, there was no fuel observed. A functional engine test was conducted, and a ground run was performed at various power settings uneventfully for about 5 minutes.

Postaccident examination of the airplane revealed no evidence of preaccident mechanical malfunctions or failures that would have precluded normal operation. The total amount of fuel onboard the airplane before the flight could not be determined; however, given the lack of fuel found in the tanks after the accident and no indications of engine anomalies, it is likely that the loss of engine power was due to fuel exhaustion.

Text from the NTSB. Open the NTSB docket for WPR23LA303 for the full record.