RIO HONDO, TX, USA
N4696L
CESSNA 172G
THE PILOT STATED THAT WHILE IN CRUISE FLIGHT AT 2,500 FEET, HE NOTICED AN INCREASE IN ENGINE RPM AND DETECTED SMOKE IN THE CABIN. AFTER REDUCING THROTTLE TO A CONTROLLABLE RPM, HE NOTICED THAT THE ENGINE OIL PRESSURE WAS ZERO. HE SUBSEQUENTLY EXECUTED A FORCED LANDING TO AN OPEN BRUSHY AREA THAT WAS THE BEST AVAILABLE. DURING ROLL OUT THE NOSE GEAR DUG INTO THE SOFT GROUND AND THE AIRPLANE FLIPPED OVER. INVESTIGATION REVEALED THAT THE PROPELLER GOVERNOR OIL LINE FITTING HAD SEPARATED DUE TO STRIPPING OF THE THREADS OUT OF THE GOVERNOR HOUSING AND THAT THE FITTING WAS INCORRECT FOR THE APPLICATION. THE AIRPLANE HAD EXPERIENCED A FORCED LANDING 13 DAYS PRIOR TO THE ACCIDENT DUE TO AN OIL LEAK AND LOSS OF OIL PRESSURE DUE TO THE JAM NUT ON THE FAILED FITTING HAVING BACKED OFF. ON THAT OCCASION, A MECHANIC TIGHTENED THE LINE AND THE AIRPLANE WAS CLEARED FOR FLIGHT.
OIL STARVATION INDUCED POWER LOSS DUE TO IMPROPER MAINTENANCE PROCEDURES. CONTRIBUTING TO THE ACCIDENT WERE INADEQUATE MAINTENANCE INSPECTION AND THE SOFT TERRAIN IN WHICH THE FORCED LANDING WAS PERFORMED.
Source: NTSB Aviation Accident Database
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