BAKER, CA, USA
N20926
PIPER PA-32RT-300T
A PIPER 32RT 300T, LANDED HARD ON DIRT STRIP AFTER EXPERIENCING A TOTAL LOSS OF ENGINE POWER. THE PILOT HEARD A LOUD BANG WHILE CRUISING AT 13,500 MSL. OIL FROM THE ENGINE OBSCURED THE PILOT'S VISION THROUGH THE WINDSHIELD. THE PILOT SECURED THE ENGINE AND SELECTED A DIRT STRIP NEAR AN AUTOMOBILE SALVAGE YARD AS A FORCED LANDING AREA. DURING THE LANDING THE AIRPLANE STRUCK AN AUTOMOBILE. SAFETY BOARD INVESTIGATORS FOUND A HOLE IN THE ENGINE CRANKCASE IN THE VICINITY OF THE NUMBER 1 AND NUMBER 2 CYLINDERS DURING THE PRELIMINARY EXAMINATION. DISASSEMBLY OF THE ENGINE REVEALED THE NUMBERS 1 AND 2 CONNECTING RODS WERE BROKEN AND THE NUMBER 1 CONNECTING ROD CONTAINED A GALLED SPOT ON ITS CONNECTING ROD BEARING SURFACE. SUBSEQUENT EXAMINATION OF THE FIVE REMAINING CONNECTING RODS REVEALED EVIDENCE OF GALLING BETWEEN THE CONNECTING ROD BEARING FACE AND ROD BEARING. ACCORDING TO THE ENGINE MANUFACTURER, GALLING BETWEEN THE CONNECTING ROD BEARING FACE AND ROD BEARING IS CAUSED BY PERIODS OF HIGH LOADING DUE TO OVERSPEED OR EXCESSIVE MANIFOLD PRESSURE. ABOUT 15 DAYS OR 6 FLIGHT HOURS, THE TURBOCHARGER WASTEGATE WAS ADJUSTED BY MAINTENANCE PERSONNEL. THE PILOT INDICATED THAT THERE WERE NO UNUSUAL INSTRUMENT INDICATIONS BEFORE THE ENGINE FAILURE.
THE UNKNOWN PILOTS IMPROPER USE OF THE THROTTLES WHICH RESULTED IN THE OVERBOOSTING OF THE ENGINE. CONTRIBUTING TO THE ACCIDENT WAS THE MAINTENANCE PERSONNEL IMPROPER MAINTENANCE IN ADJUSTING THE TURBOCHARGER WASTEGATE AND THE OIL LEAKING FROM THE ENGINE AFTER THE CATASTROPHIC FAILURE WHICH RESTRICTED THE PILOT'S VISUAL OUTLOOK.
Source: NTSB Aviation Accident Database
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