NTSB Identification: MKC82IA137
14 CFR Part 91: General Aviation
Incident occurred Thursday, August 05, 1982 in ST. JOSEPH, MO
Probable Cause Approval Date: 08/05/1983
Aircraft: MITSUBISHI MU-2B-25, registration: N312MA
Injuries: 2 Uninjured.

NTSB investigators used data provided by various sources and may not have traveled in support of this investigation to prepare this aircraft incident report.

AFTER TAKEOFF, THE PILOT WAS CLEARED TO CLIMB TO 6000 FT MSL. WHILE CLIMBING THROUGH ABOUT 5000 FT, HE HEARD A LOUD NOISE (BAM) AS THE LEFT ENGINE LOST POWER. THE LEFT ENGINE WAS SHUT DOWN AND FEATHERED AND A LANDING WAS MADE WITH NO OTHER PROBLEMS. AN INVESTIGATION REVEALED THAT THE THIRD STAGE TURBINE WHEEL HAD FAILED FROM FATIGUE. PORTIONS OF THE WHEEL, PROPELLED BY CENTRIFUGAL FORCE, EXITED THE RIGHT SIDE OF THE ENGINE CASE AND PENETRATED THE LEFT SIDE OF THE CABIN, RESULTING IN MINOR DAMAGE. THE FAILURE CREATED AN UNBALANCED CONDITION IN THE TURBINE SECTION WHICH ALLOWED AN ASYMMETERICAL LOAD TO BE APPLIED TO THE REAR MAIN BEARING SUPPORT. SUBSEQUENTLY, THE BEARING SUPPORT FAILED, SEPARATED AND IMPACTED THE LEADING EDGE OF THE LEFT HORIZONTAL STABILIZER.

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

TURBINE ASSEMBLY,TURBINE WHEEL..DISINTEGRATED


Contributing Factors

MAINTENANCE,COMPLIANCE WITH AD..NOT PERFORMED..OTHER MAINTENANCE PERSONNEL


Contributing Factors

INADEQUATE QUALITY CONTROL..OTHER MAINTENANCE PERSONNEL

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