On September 10, 1994, a Cessna 175 (registration N7554M) was involved in an aviation accident near Oklahoma City, OK. Investigators recorded the probable cause as: IMPROPER MAINTENANCE OF THE ENGINE BY UNKNOWN PERSON(S), THE INSTALLATION OF UNAPPROVED PARTS, AND SUBSEQUENT BEARING SEIZURE. THE LACK OF SUITABLE TERRAIN IN THE FORCED LANDING AREA WAS A RELATED FACTOR. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During takeoff initial climb, engine sounds ceased and the propeller stopped vertical. The airplane touched down beyond the runway, traversed rough terrain, hit a dirt bank, became airborne, and descended into a 25-foot ravine. Examination revealed incorrect and seized bearings.
Incident Summary
Witnesses reported that during the takeoff initial climb, engine sounds ceased and the propeller stopped in a vertical position. The airplane touched down on a grassy area beyond the departure end of the runway. After traversing rough and uneven terrain, it encountered a dirt bank and became airborne. The airplane then descended into a 25-foot deep ravine.
Examination Findings
An examination of the engine revealed it was binding during rotation. The front reduction gear case was removed. The propeller shaft thrust bearings fit loosely about the journal, exhibited scratches, and were not the correct bearings. Both the propeller driver gear front bearing and rear bearing were solid brass bearings, whereas the manufacturer print specifications for these bearings listed a steel backed split bearing. The front bearing was seized to the propeller drive gear. The crankcase and the forward gear case exhibited galling and metal debris, which was identified as aluminum from the main gear case. The engine main bearings and rod bearings exhibited scratches.