On December 20, 1984, a Grumman AA-5B (registration N74463) was involved in an aviation accident near Corona, CA. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During maintenance, a crankshaft gear bolt was improperly tightened, causing engine failure. The pilot then struck a ditch during an emergency landing after failing to lower flaps.
Incident Overview
During maintenance of the engine, just before the annual inspection was signed off, an individual partially loosened and then attempted to tighten the bolt securing the crankshaft gear to the crankshaft. The old lockplate was not replaced and was not properly secured about the bolt.
Engine Failure
As a result of a loose bolt, the dowel pin that aligns the gear with the crankshaft shifted, causing the gear to move out of position. This led to the engine stopping.
Emergency Landing
The pilot failed to lower the wing flaps during the subsequent emergency landing. The aircraft struck a dirt ditch short of the intended landing site.