On September 2, 1985, a Cessna 177 (registration N30654) was involved in an aviation accident near Glandorf, OH. Investigators recorded the probable cause as: The engine's loss of power due to internal mechanical failure, evidenced by the damaged connecting rod and crankshaft journal. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot executed a forced landing after engine oil pressure dropped to zero and the propeller pitch varied during cruise flight, resulting in the aircraft contacting a ditch.
What happened
During cruise flight, the pilot reported that the propeller pitch began to vary unexpectedly. Shortly thereafter, the engine oil pressure dropped to zero, and the engine began to overheat. These mechanical failures necessitated an emergency procedure, leading to a forced landing attempt. During this maneuver, the aircraft made contact with a ditch.
The investigation
A post-accident examination of the engine revealed significant internal damage. Specifically, the number three cylinder connecting rod and the crankshaft journal were found to be badly burned and scarred, indicating severe mechanical failure within the engine assembly.
Probable cause
The engine's loss of power due to internal mechanical failure, evidenced by the damaged connecting rod and crankshaft journal.