Grumman American Avn. Corp. AA-5A N26118 accident near Lakeview, Oregon

Probable cause

A partial loss of engine power during the initial climb due to a stuck exhaust valve.

NTSB analysis

The pilot reported that the preflight run-up was uneventful. Shortly after takeoff, at approximately 150 feet above ground level, the engine suddenly dropped rpm; the pilot verified fuel quantity, and attempted to lean the engine. Despite the pilot’s efforts, the problem persisted, and he initiated a forced landing into a nearby field. During the landing roll, the airplane’s left wing struck a fence post, and its empennage collided with high sage brush. Examination of the engine by a certificated airframe and powerplant (A&P) mechanic revealed low compression within the number three cylinder. Further examination revealed that the exhaust valve was stuck in the full open position. The examination revealed no further anomalies with the cylinder assembly or engine.

Text from the NTSB. Open the NTSB docket for WPR10LA424 for the full record.