Grumman AA1 N8866L accident near Portland, Tennessee

Probable cause

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

NTSB analysis

The private pilot and the passenger were making a local personal flight in the airplane. According to witnesses, the airplane was flying "low" in the vicinity of the runway when it collided with trees and impacted terrain in a nose-down attitude. Examination of the airplane revealed that the fuel selector was in the left tank position; there was no fuel in the left tank or in the fuel lines, and there was less than 1 teaspoon of fuel in the electric boost pump. Therefore, it is likely that the engine lost power because of fuel exhaustion.

At an unknown time, the airplane's original 108-horsepower engine had been replaced with a 150-horsepower engine. An updated pilot operating handbook or operating handbook supplement that would have provided fuel consumption figures for the higher horsepower engine was not located. When the accident occurred, the airplane had been flown about 2.23 hours since it had been fully fueled. Based on the estimated fuel burn rate of between 8.8 and 10 gallons per hour provided by the engine manufacturer for the 150-horsepower engine, the airplane likely would have consumed its entire usable fuel capacity of 22 gallons about the time of the accident.

Text from the NTSB. Open the NTSB docket for ERA17FA299 for the full record.