NTSB Identification: LAX85FA130.
The docket is stored on NTSB microfiche number 27927.
Accident occurred Thursday, January 31, 1985 in BISHOP, CA
Aircraft: PIPER PA-32RT-300T, registration: N2129G
Injuries: 4 Uninjured.

NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

THE PLT RPTD THAT SHORTLY AFTER LEVELING OFF AT 11500 FT MSL, THE ENGINE EXPLODED CAUSING BOTH WINDSCREENS TO BE COVERED WITH OIL AND FIRE. THE FIRE STOPPED DURING THE EMERGENCY DESCENT. THE ACFT LANDED ON RY 30 AT BISHOP ARPT, BISHOP, CA WITHOUT FURTHER INCIDENT. DISASSEMBLY EXAMINATION OF THE ENGINE REVEALED CRANKSHAFT FAILED AT THE SHORT CHEEK BETWEEN THE NO. 3 MAIN JOURNAL & THE NO. 4 CRANKPIN. THE NOS. 3 & 4 CONNECTING RODS & CAMSHAFT WERE FRACTURED. THE PISTONS SHOWED NO EVIDENCE OF ANY DETONATION. THE BACKSIDE OF THE CON RODS, MAIN JOURNAL BEARINGS & BOTH HALVES OF THE CRANKCASE SHOWED EXTENSIVE FRETTING SIGNATURES INDICATING MISALIGNMENT DURING MANUFACTURE. METALLURGICAL EXAMINATION REVEALED THE CRANKSHAFT FAILED IN FATIGUE. ALL OTHER FRACTURES WERE OVERLOAD SUBSEQUENT TO THE CRANKSHAFT FAILURE. THE ENGINE HAD ACCUMULATED 602 FLT HOURS SINCE NEW.

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

ENGINE ASSEMBLY,CRANKSHAFT..FAILURE,TOTAL

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

MAINTENANCE,ALIGNMENT..IMPROPER..MANUFACTURER

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

ENGINE ASSEMBLY,CRANKSHAFT..FATIGUE


Contributing Factors

FLUID,OIL..FIRE


Contributing Factors

ENGINE ASSEMBLY,CONNECTING ROD..OVERLOAD

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