Beech M35 N9876R accident near Henderson, Nevada

Probable cause

The flight instructor’s failure to verify the fuel quantity and improper fuel management, which resulted in fuel starvation and a total loss of engine power.

NTSB analysis

The flight instructor performed a walkaround preflight inspection of the airplane and reported that he visually inspected each of the airplane’s 6 fuel tanks. He reported that the right main fuel tank was full. The flight instructor and pilot receiving instruction (the pilot) departed with the fuel selector on the left main fuel tank. After 40 minutes of flight time, the pilot selected the right main fuel tank and about 25 minutes later they noticed that the fuel quantity indicator still showed that the right tank was full. After a brief discussion they determined they had sufficient fuel to complete the trip and dismissed the abnormality. About 15 minutes later, while on short final approach, the pilot increased the airplane pitch attitude and added power, but did not receive a response from the engine, nor was there a response when he advanced the throttle to full power. The instructor selected the left main tank, but the engine did not respond, and the airplane continued to descend. The airplane impacted a berm during its subsequent forced landing and came to rest with the pilot at the controls.

The right fuel tank was selected for 25 minutes during the flight and the postaccident examination revealed the fuel tank was empty while the left fuel tank, which was used for 40 minutes, was still ¾ full. The examination of the right fuel tank did not reveal any breaches in the fuel tank or fuel lines.

The examination did reveal the right fuel tank fuel bladder had separated from the bottom of the fuel tank. The examination also discovered that the right main fuel tank gauge erroneously reported between ½ and ¾ full throughout the entire range of the float sensor position, consistent with the flight data and flight crew’s observations during the flight. While this evidence suggests a failure in the fuel quantity indication system, it didn’t likely contribute to the accident as the flight crew recognized the discrepancy during the flight and chose to rely on the instructor’s visual inspection of the fluid level during the preflight.

The accident was the result of the instructor’s failure to verify the fuel quantity prior to departure and improper fuel management, which resulted in fuel starvation and a total loss of engine power.

Text from the NTSB. Open the NTSB docket for WPR22LA349 for the full record.