Amateur-built AVID FLYER N3HH accident near Wetumpka, Alabama

Probable cause

A loss of engine power due to fuel exhaustion because of a leaking fuel drain valve.

NTSB analysis

The pilot was flying his experimental airplane from Florida to Alabama. The airplane was equipped with a 15-gallon fuel tank and the engine consumed about 4.5 gallons of fuel per hour. The pilot said he departed with full fuel and then made 4 fuel stops along the route, stopping about every 70 to 90 minutes. At each stop he filled the fuel tank. On his last fuel stop, after he filled the fuel tank, he took a sample of fuel from the tank’s fuel drain valve to check for water and noticed a few drips of fuel coming from the valve, but no major leaks. The pilot then departed on his final leg of the trip. About 90 minutes into the flight, the engine stopped producing power, and the pilot noted that the fuel sight tube was completely empty. The pilot made a forced landing, resulting in substantial damage to the airframe.

A postaccident examination of the airplane revealed the fuel tank was intact and empty. No other breaches in the fuel system were observed; however, blue staining was noted around the fuel sump-valve consistent with it having been leaking. Fuel staining was also observed on the right flaperon. The pilot said the fuel valve was leaking a few months before the accident, but he fixed it and had not had another problem with the drain valve until the accident flight. Based on this information, it is likely that fuel leaking from the drain valve decreased the amount of fuel available over the duration of the accident flight, ultimately resulting in fuel exhaustion and a subsequent total loss of engine power.

Text from the NTSB. Open the NTSB docket for ERA23LA325 for the full record.