Casualties unknown

Engine Failure During Base Leg Results in Crash (N3393A)

Franklin Center, PA, US

On June 17, 1990, a Piper PA-22-135 (registration N3393A) was involved in an aviation accident near Franklin Center, PA. Investigators recorded the probable cause as: Loss of engine power due to carburetor icing, which was likely induced by the application of carburetor heat in high-temperature and high-humidity conditions. 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 2026-06-10Data APIEditorial standards

An aircraft experienced a sudden loss of power while on base leg near the airport after carburetor heat was applied, leading to an unrecoverable descent and impact.

What happened

The incident occurred when the airplane was positioned on the base leg, approximately one mile from the airport. At this stage of the approach, the pilot applied carburetor heat. Immediately following this action, the engine surged before losing power completely. The engine could not be restarted during the subsequent descent. The aircraft impacted the ground in a nose-low attitude with the left wing low.

Findings

Post-accident examination revealed no evidence of a pre-existing failure or mechanical malfunction within the engine prior to the event. Environmental conditions at the time were significant, with a temperature recorded at 89 degrees Fahrenheit and a dewpoint of 68 degrees Fahrenheit located 11 miles away from the accident site.

Safety message

The application of carburetor heat in high-temperature, high-humidity conditions can lead to rapid power loss due to ice formation or vapor lock. Pilots must be aware that sudden engine surging followed by power loss may indicate carburetor icing issues exacerbated by weather.

Probable cause

Loss of engine power due to carburetor icing, which was likely induced by the application of carburetor heat in high-temperature and high-humidity conditions.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X23525. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.