NTSB Identification: FTW93LA216.
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Accident occurred Saturday, July 24, 1993 in PURCELL, OK
Probable Cause Approval Date: 09/26/1994
Aircraft: CESSNA 172N, registration: N4884G
Injuries: 2 Uninjured.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.THE AIRPLANE COLLIDED WITH ROUGH TERRAIN DURING A NIGHT FORCED LANDING FOLLOWING A PARTIAL POWER LOSS. THE ACCIDENT OCCURRED DURING A NIGHT DUAL INSTRUCTIONAL FLIGHT AND THE INSTRUCTOR MADE THE FORCED LANDING. INVESTIGATION REVEALED THAT THE #3 EXHAUST VALVE ROCKER ARM ATTACHMENT STUD HAD FAILED IN FATIGUE. THE SEPARATED STUD SUBSEQUENTLY LODGED UNDER THE #3 INTAKE VALVE MECHANISM AND THE CORRESPONDING PUSH ROD WAS BENT. THE ENGINE AND SUBJECT PARTS HAD ACCUMULATED A TOTAL OF 2,903.5 HOURS.
The National Transportation Safety Board determines the probable cause(s) of this accident to be:
THE LACK OF SUITABLE TERRAIN ONTO WHICH TO EXECUTE THE FORCED LANDING WHICH WAS NECCESITATED BY THE PARTIAL POWER LOSS. THE POWER LOSS WAS A RESULT OF THE FATIGUE FAILURE OF THE EXHAUST VALVE ROCKER ARM ATTACHMENT STUD. A FACTOR WAS THE NIGHT CONDITIONS. Full narrative availableIndex for Jul1993 | Index of months