Mooney M20C N78988 accident near Reno, Nevada

Probable cause

The pilot's improper inflight fuel management, which resulted in fuel starvation and a total loss of engine power.

NTSB analysis

The pilot and two passengers departed on a cross-country flight. As they approached the destination airport, shortly after the pilot switched the fuel tank selector from the left tank to the right tank, the engine lost total power. During the subsequent forced landing, the airplane impacted a fence and then the ground, resulting in substantial damage to the left wing.

Examination of the airplane revealed no preimpact anomalies with the engine, which ran continuously and displayed no anomalies. Fuel computations based on a photo of the airplane’s fuel gauges before departure indicated that the airplane should have contained enough fuel to complete the flight; however, the left fuel gauge and sender may have erroneously indicated that the left fuel tank contained a greater fuel quantity than it actually did. Testing of the fuel gauge and sender was inconclusive due the unknown condition of the units at the time of the accident.

The pilot did not have a means to visually confirm fuel quantities other than full and regularly computed his fuel remaining by calculating the total fuel consumption for each flight, using the fuel quantity gauges as a secondary indicator. During flight, he balanced his fuel levels by switching tanks every 30 minutes; however, the pilot stated that during the flight before the accident, he may have become task saturated and forgot to switch tanks, which would have created a fuel imbalance and rendered his fuel computation incorrect for the accident flight. It is likely that the fuel quantity in the right tank was several gallons less than what the pilot calculated, which resulted in a total loss of engine power due to fuel starvation.

Text from the NTSB. Open the NTSB docket for WPR19LA243 for the full record.