# NTSB NYC91LA250: Mitsubishi MU-2B-60, Utica, NY, September 27, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: September 27, 1991, 13:15 local (18:15 UTC)
- Place: Utica, NY
- Location: 43.0964° N, 75.2260° W: Placed by OpenAirDocs: center of Utica, NY, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=43.0964&lon=-75.2260&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report May 3, 1993
- Report: Approved by Office Director
- Safety recommendations: Yes
- NTSB case key (mKey): 37023
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC91LA250
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/37023/pdf
- Page: https://openairdocs.org/ntsb/NYC91LA250

## Probable cause

FATIGUE CRACKING OF THE PROPELLER HUB.

## Sequence of events

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

- Airframe/component/system failure/malfunction, climb - to cruise
  - propeller system/accessories,hub - corroded
  - propeller system/accessories,hub - fatigue (cause)
  - propeller system/accessories,hub - fractured

## Analysis

DURING CLIMB, ONE OF THE FOUR PROPELLER BLADES ON THE NUMBER TWO ENGINE SEPARATED FROM THE PROPELLER HUB, DAMAGING ANOTHER PROPELLER BLADE AND THE FUSELAGE.  SHORTLY THEREAFTER, THE ENGINE SHUT DOWN.  THE ROTATIONAL UNBALANCE WAS ACCOMPANIED BY EXTREME VIBRATION AND RESULTED IN DISTORTION AND DAMAGE TO THE ENGINE/COWL ASSEMBLY AND THE WING.  THE UPPER PORTION OF THE ENGINE COWL WAS DEFLECTED UPWARD OVER THE WING AT AN ANGLE OF ABOUT 30 DEG, RESULTING IN DISTORTION OF AIRFLOW, BUFFETING, AND DEGRADATION OF ROLL CONTROL.  DUE TO EXCESSIVE DRAG, MAXIMUM POWER WAS REQUIRED ON THE NUMBER ONE ENGINE IN ORDER TO CONTROL THE RATE OF DESCENT AND LAND SUCCESSFULLY.  A METALLURGICAL EXAMINATION DISCLOSED EVIDENCE OF FATIGUE CRACKING OF THE PROPELLER HUB ARM.

## Aircraft

- Registration: CFFSS (not matched to a registry record)
- Reported make and model: MITSUBISHI MU-2B-60
- Category: Airplane
- Serial number: 783SA
- Airframe hours: 4756
- Engines: GARRETT TPE331-10511M 715 horsepower turbo prop
- Damage: Substantial damage
- Flight: Part 129
- Operator: Air 500 Limited
- Registered owner: Air 500 Limited
- Airworthiness certificate: Standard, Transport
- Last inspection: AAIP, September 15, 1991, 21 hours before
- Departed: SYR, SYRACUSE, NY
- Destination: BED, BEDFORD, MA
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 27; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 7,633 total, 1,100 in this make and model, 7,205 as pilot in command, 242 in the last 90 days, 99 in the last 30 days, 9 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 70 °F

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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