On August 26, 1993, a Piper PA-25-225 (registration N9556P) was involved in an aviation accident near Chesapeake, VA. Investigators recorded the probable cause as: The crankshaft gear was loose, the alignment pin and attachment bolt were sheared, and the crankshaft gear and magneto drive gear had ten teeth broken off. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A crop spraying airplane lost engine power and made a forced landing in tall crops, nosing over. An engine exam revealed a loose crankshaft gear, sheared alignment pin and bolt, and broken teeth on the crankshaft and magneto drive gears.
Accident Overview
The pilot was conducting a crop spraying flight when the engine suddenly lost power. The aircraft was too low to attempt an engine restart, prompting the pilot to initiate a forced landing into a field with tall crops.
Forced Landing and Nose-Over
During the landing, the airplane nosed over. The tall crops likely contributed to the sudden deceleration that caused the aircraft to pitch forward.
Engine Examination
After the accident, an examination of the engine revealed significant mechanical failures. The crankshaft gear was found to be loose, and both the alignment pin and attachment bolt were sheared. Additionally, the crankshaft gear and the magneto drive gear had ten teeth broken off.
Probable cause
The crankshaft gear was loose, the alignment pin and attachment bolt were sheared, and the crankshaft gear and magneto drive gear had ten teeth broken off.