Cessna R172 N1609V accident near North Garden, Virginia

Probable cause

A total loss of engine power due to the failure of the oil pump drive gear.

NTSB analysis

The pilot was on a cross country flight when an oil pressure warning displayed on the airplane’s flight display. The pilot diverted toward another airport but the engine seized enroute. The pilot performed a forced landing to a field, where the airplane hit obstacles and flipped over. Both wings, the empennage, and the fuselage sustained substantial damage.

After the accident the engine was examined and determined to have failed due to an oil starvation event. The oil pump drive gear was found failed and had separated from the shaft portion of the gear assembly. The fracture surfaces were examined, and multiple fracture origins were identified.

Improvements to the oil pump drive gear were made and a service bulletin was released in 1996 which required the replacement of the drive gear at the next engine overhaul. The engine examination determined that this service bulletin had not been complied with. The maintenance records that were provided only went back two years and covered two annual inspections of the engine. The most recent annual inspection record indicated that the engine had been overhauled and had accumulated 1,975 hours since overhaul. The record of the overhaul was not in the maintenance records received by investigators.

Text from the NTSB. Open the NTSB docket for CEN19LA258 for the full record.