Cessna 177 RG N52670 accident near Gilford, New Hampshire

Probable cause

A loss of engine power due to oil exhaustion from the fracture of the nipple for the engine oil cooler return line. Contributing to the accident was the mechanic's signoff and release of the airplane without performing the required engine run-up following an annual inspection.

NTSB analysis

On the initial flight following an incomplete annual inspection, the airplane experienced a total loss of engine power and impacted a tree during the resultant forced landing. The airframe and powerplant (A&P) with an inspection authorization (IA) rated mechanic reported that he signed off the logbooks with the expectation that another mechanic would perform an engine run-up prior to flight. Federal Aviation regulations did not allow delegation of authority with regards to the inspection and that the IA must perform the inspection prior to approving the airplane for return to service. The accident pilot arrived to the maintenance facility prior to the A&P mechanic, retrieved the logbooks that were signed off, and departed. Oil was noticed on the taxiway that services the maintenance facility, in the engine run-up area, and leading to the runway. The oil cooler return line attach nipple was fractured and gouges were noted on the surface of the hose end socket caused by an inadvertent contact by a wrench slipping off of a nearby bolt or nut and striking the surface of the hose end socket. Results of toxicology testing were consistent with recent use of marijuana and amphetamine. It could not be determined whether impairment due to such use may have played a role in the accident.

Text from the NTSB. Open the NTSB docket for ERA09FA343 for the full record.