# NTSB MKC82IA137: Mitsubishi MU-2B-25, N312MA, St. Joseph, MO, August 5, 1982

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: August 5, 1982, 15:45 local (20:45 UTC)
- Place: St. Joseph, MO
- Coordinates: 39.84972, -94.819595 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=39.8497&lon=-94.8196&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report August 5, 1983
- Report: Approved by Office Director
- NTSB case key (mKey): 72699
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MKC82IA137
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/72699/pdf
- Page: https://openairdocs.org/ntsb/MKC82IA137

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of engine power(total) - mech failure/malf, climb - to cruise
  - turbine assembly,turbine wheel - disintegrated (cause)
  - maintenance,compliance with ad - not performed, other maintenance personnel (contributing factor)
  - inadequate quality control, other maintenance personnel (contributing factor)

## Analysis

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.

## Aircraft

- Registration: [N312MA](https://openairdocs.org/deregistered/N312MA-2012-09-25), registration cancelled 2012-09-25, S/N 266, built 1973 (OpenAirDocs)
- Reported make and model: MITSUBISHI MU-2B-25
- Registry model: [Mitsubishi MU-2B-25](https://openairdocs.org/model/mitsubishi-mu-2b-25) (registry code 5780409) (OpenAirDocs)
- Registry engine: [AiResearch 331 SER 605HP](https://openairdocs.org/engine/airesearch-331-ser-605hp) (registry code 01502, turbo-prop) (OpenAirDocs)
- Category: Airplane
- Serial number: 266
- Airframe hours: 2465
- Engines: GARRETT TPE-331-6-251 724 horsepower turbo prop
- Damage: Minor damage
- Fire: In-Flight
- Flight: Business, Part 91
- Operator: Bio Zyme Enterprise, Inc.
- Registered owner: Bio Zyme Enterprise, Inc.
- Departed: STJ, ST. JOSEPH, MO
- Destination: H-76, PAWHUSKA, OK
- Flight plan: IFR
- Airport: STJ, Rosecrans Memorial, runway 17, 8,059 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; commercial, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; flight hours: 13,553 total, 2,198 in this make and model, 106 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 10 knots
- Visibility: 10 statute miles
- Temperature: 176 °F
- Altimeter: 30.00 inHg

## Other investigations on N312MA (2)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB SEA05FA105](https://openairdocs.org/ntsb/SEA05FA105), May 25, 2005: Mitsubishi MU-2B-25 (N312MA), Hillsboro, OR, substantial damage, 4 fatal. Probable cause: The pilot's failure to obtain minimum controllable airspeed during the takeoff climb, which resulted in a loss of aircraft control when the left engine lost partial power. A fatigue failure to an oil…
- [NTSB OAK79FVG43](https://openairdocs.org/ntsb/OAK79FVG43), May 25, 1979: Mitsubishi MU2 (N312MA), Sacramento, CA, minor damage

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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