Piper PA-32R-301T N362DM accident near Riverview, Florida

Probable cause

Damage to the propeller governor gasket during installation by unknown persons, which resulted in a total loss of engine oil in flight and a subsequent forced landing.

NTSB analysis

The airplane experienced an electrical discrepancy shortly after an instrument departure. The pilot advised the air traffic controller that he would be returning to the airport. While en route, the pilot noted a film of oil on the windshield. It became more pronounced, and the engine oil pressure dropped to “0.” The pilot declared an emergency and landed the airplane on an interstate highway median. An 8-foot section of the left wing separated when it collided with a highway traffic sign during the landing roll. The postaccident engine examination revealed that the oil leak was from the propeller governor gasket; specifically, the leak originated from the lower left lock nut area that secures the control cable tube end support bracket to the governor’s engine-mounted stud. The nut and lock washer were not properly seated and anti-tamper putty was present. The disassembly of that area revealed that the lower left corner of the gasket had several cracks promulgating to that lower left section of the gasket, which permitted the oil to escape. The top section of the tube end of the support bracket was missing (broken off), which would not allow for an even mounting torque pressure between the gasket, the propeller governor, and the engine surfaces.

A review of the airplane’s maintenance records revealed no history of any discrepancies that would require the removal of the control cable support bracket tube end. Based on physical damage to the control cable bracket tube end, it is likely that, at an unknown time, the tube end was removed from the stud and damaged during installation. This did not permit a proper seal of the gasket, which created the leak.

Text from the NTSB. Open the NTSB docket for ERA12LA524 for the full record.