On September 11, 1996, a Cessna 177RG (registration N2797V) was involved in an aviation accident near Colorado Sprngs, CO. Investigators recorded the probable cause as: Failure of maintenance personnel to install one of two required gaskets and a governor pad as required by Textron Lycoming Service Instruction No. 1438, dated July 9, 1987, which allowed engine oil to be depleted. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A maintenance test flight ended when the engine seized after a reported runaway prop. The pilot overshot a soccer field and landed on a street, colliding with two vehicles. Missing gaskets caused oil depletion.
Incident Details
The aircraft had a factory overhauled engine installed and was on a maintenance test flight. Eleven minutes after takeoff, the pilot reported a runaway propeller. Shortly thereafter, the engine seized. The pilot attempted to return to the airport but determined he was too far away. He selected a soccer field for a forced landing but misjudged airspeed and altitude, overshooting the field. The pilot landed on a street and collided with two vehicles.
Maintenance Error
Removal of the propeller governor revealed that maintenance personnel had failed to install one of two required gaskets and a governor pad, as specified by Textron Lycoming Service Instruction No. 1438, dated July 9, 1987. This omission allowed engine oil to be depleted, leading to the engine seizure.
Conclusion
The accident was caused by maintenance personnel's failure to install the proper gaskets and governor pad during the engine installation.
Probable cause
Failure of maintenance personnel to install one of two required gaskets and a governor pad as required by Textron Lycoming Service Instruction No. 1438, dated July 9, 1987, which allowed engine oil to be depleted.