THE AIRCRAFT LOST POWER SHORTLY AFTER TAKEOFF AND COLLIDED WITH A DIRT BANK DURING THE SUBSEQUENT FORCED LANDING. ENGINEEXAMINATION REVEALED AN OPEN INTAKE VALVE ON THE NUMBER 4 CYLINDER AND THE PILOT STATED A 'BENT AND CRACKED CRANKSHAFT FROM A PRIOR ACCIDENT' WAS DISCOVERED DURING THE ENGINE EXAMINATION. THE ENGINE MANUFACTURER STATED THAT AN OPEN INTAKE VALVE COULD INDUCE SIGNIFICANT POWER LOSS BY ALLOWING EXHAUST GASSES TO PRESSURIZE THE INTAKE MANIFOLD, THEREBY ALTERINGTHE FUEL/AIR MIXTURE. THE MAINTENANCE RECORDS ESTABLISHED THAT THE AIRCRAFT HAD FLOWN ONLY NINE HOURS SINCE THE LAST CONDITION INSPECTION.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

Contributing Factors

TERRAIN CONDITION..NONE SUITABLE

Contributing Factors

TERRAIN CONDITION..DIRT BANK/RISING EMBANKMENT

Index for Jul1987 | Index of months