Cessna 172P N63835 accident near Spruce Creek, Florida

Probable cause

A total loss of engine power due to fuel exhaustion, which resulted from the pilots’ improper preflight and in-flight fuel planning.

NTSB analysis

The flight instructor and pilot receiving instruction departed on a training flight, and the pilot stated that the fuel tanks were "almost full." After 3 hours 24 minutes of flight, which included three full-power takeoffs and climbs, the engine experienced a total loss of power on final approach to the destination airport. According to Federal Aviation Administration air traffic control records, multiple one-leg flight plans were filed for the flight. Based on this information, the estimated fuel endurance was 3 hours 20 minutes.

The pilot receiving instruction stated that the fuel selector was in the "both" position throughout the flight but that, on final approach, he noticed that the fuel selector had been switched to the "right" tank position, so he moved the fuel selector back to the "both" position. Shortly thereafter, the engine stopped producing power. The flight instructor stated that the pilot inadvertently selected the "off" position instead of the "both" position when he moved the fuel selector from the "right" tank position.

During the subsequent forced landing, the airplane's cabin and fuselage were damaged, but both wing fuel tanks remained intact. No signs of in-flight or postaccident fuel leakage were found. Postaccident examination showed that the left wing tank contained no fuel and that the right wing tank contained about 3 gallons of fuel. A test run of the engine was performed following the accident using the fuel found in the right wing tank. The engine started immediately, accelerated smoothly, and ran continuously with no anomalies observed. According to the airplane manufacturer, the airplane's fuel tanks had a total capacity of 43 gallons, of which 3 gallons were unusable. Based on this information, it is likely that the pilots exhausted all of the usable fuel during the flight, which resulted in a total loss of engine power on final approach to their destination airport.

Text from the NTSB. Open the NTSB docket for ERA14LA434 for the full record.