Alon A2 N6364V accident near Apex, North Carolina

Probable cause

A total loss of engine power during initial climb for reasons that could not be determined during postaccident examination and testing.

NTSB analysis

The pilot stated that, before the accident flight, the airplane had about 15 gallons of automotive gasoline in the fuel tanks. The taxi and initial takeoff were "normal"; however, when the airplane was about 100 ft above the trees that bordered the airport, the engine experienced a sudden total loss of power. The pilot then reduced the throttle and reapplied full throttle. Although the engine momentarily restarted, it then immediately lost power. The airplane subsequently impacted trees and came to rest inverted. Local authorities reported a strong fuel smell at the accident location, but the exact amount of spilled fuel could not be determined. Examination of the airframe and a subsequent test run of the engine revealed no mechanical anomalies that would have precluded normal operation.

Federal Aviation Administration guidance indicates that vapor lock is a problem that mostly affects gasoline-fueled internal combustion engines and can result in a transient or complete loss of power. The guidance further states that restarting the engine from this state may be difficult because fuel can be vaporized by engine heat. Given that the ambient air temperature, the fuel flow condition (takeoff), and the likely engine temperature were conducive to the occurrence of vapor lock, it is possible that the loss of engine power was due to vapor lock; however, insufficient evidence existed to determine whether vapor lock occurred during the accident flight. The weather conditions about the time of the accident were conducive to the accumulation of carburetor icing at cruise and glide power; however, given the pilot's statement that the engine operated "normally" until the sudden loss of power and that the airplane was climbing at a high power setting, it is not likely that the carburetor accumulated ice.

Text from the NTSB. Open the NTSB docket for ERA14LA208 for the full record.