On July 11, 1992, a Grumman AA5 (registration N28410) operated by Advanced Aero Dynamics & Struc was involved in an aviation accident near Soledad, CA. Investigators recorded the probable cause as: THE LOSS OF ENGINE POWER FOR UNDETERMINED REASONS AND THE LACK OF SUITABLE TERRAIN FOR A FORCED LANDING. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
After an oil pressure decrease, a pilot attempted a precautionary highway landing. The engine lost power on final approach, leading to a tree strike and a nose-down landing that collapsed the nose and left main landing gear. Engine examination found no preexisting malfunctions.
Accident Overview
Approximately one hour and fifteen minutes into a cross-country flight, the pilot observed that the engine oil pressure was decreasing. In response, the pilot elected to make a precautionary landing on a highway.
Sequence of Events
As the aircraft turned onto the final approach for the highway, the engine lost power. Subsequently, the aircraft's right wing collided with a tree. Following the wing strike, the aircraft struck the road in a nose-down attitude. The impact caused the collapse of the nose landing gear and the left main landing gear.
Post-Accident Examination
An examination of the engine was conducted. The examination failed to disclose any preexisting malfunctions or failures that could account for the loss of engine power.