Casualties unknown

1992-05-22: Piper PA-12 (N3717M) — Bruce Johnson — Port Bainbridge, AK

Port Bainbridge, AK, US

On May 22, 1992, a Piper PA-12 (registration N3717M) operated by Bruce Johnson was involved in an aviation accident near Port Bainbridge, AK. Investigators recorded the probable cause as: The pilot's decision to use automotive fuel and the probable failure to apply carburetor heat, which resulted in engine power loss due to ice accumulation or improper combustion. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

A pilot experienced an in-flight engine failure during a low-pass maneuver over a beach while attempting to land. Investigation revealed the use of automotive fuel and potential carburetor icing as primary factors.

What happened

The pilot initiated a low pass over a beach area with the intention of executing a landing on the sand. During this maneuver, the pilot applied full throttle to gain altitude. The aircraft climbed to approximately 300 feet above ground level before the engine ceased producing power. The sudden loss of thrust resulted in an emergency situation requiring immediate attention.

The investigation

Following the incident, investigators examined both the engine and the airframe to determine the cause of the power interruption. The mechanical inspection revealed no evidence of internal engine failure or structural damage that would explain the loss of power. The components appeared functional from a mechanical standpoint, suggesting an operational or environmental cause rather than a hardware defect.

Findings

The investigation highlighted two critical factors contributing to the event. First, the pilot was utilizing automotive fuel instead of aviation-grade gasoline, which is unsuitable for aircraft engines. Second, the pilot could not recall whether carburetor heat had been applied during the low pass. The combination of inappropriate fuel and potential carburetor icing likely led to fuel starvation or ice accumulation within the carburetor, causing the engine to stop.

Safety message

Pilots must ensure they use only approved aviation fuels for their aircraft. Additionally, proper application of carburetor heat is essential during low-power operations to prevent icing, which can cause sudden engine failure.

Probable cause

The pilot's decision to use automotive fuel and the probable failure to apply carburetor heat, which resulted in engine power loss due to ice accumulation or improper combustion.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X14552. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.