# NTSB FTW91FA043: Mitsubishi MU-2B-60, N274MA, Tulsa, OK, February 22, 1991

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: February 22, 1991, 15:19 local (21:19 UTC)
- Place: Tulsa, OK
- Coordinates: 36.190727, -95.910896 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.1907&lon=-95.9109&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 3 fatal
- Status: Completed, report January 28, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 23250
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW91FA043
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/23250/pdf
- Page: https://openairdocs.org/ntsb/FTW91FA043

## Probable cause

THE SHUTDOWN OF ONE ENGINE FOR UNDETERMINED REASONS, AND THE PILOT'S FAILURE TO MAINTAIN VMCA DURING A CRITICAL PHASE OF FLIGHT. A FACTOR IN THE ACCIDENT WAS THE PILOT'S IMPROPER EMERGENCY PROCEDURE.

## Sequence of events

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

- Loss of engine power(total) - nonmechanical, takeoff - initial climb
  - 1 engine
  - reason for occurrence undetermined (cause)
  - propeller feathering - performed, pilot in command
- Loss of control - in flight, takeoff - initial climb
  - airspeed(vmc) - not maintained, pilot in command (cause)
  - emergency procedure - improper, pilot in command (contributing factor)
- In flight collision with terrain/water, takeoff - initial climb

## Analysis

AIRPLANE WAS DEPARTING ON A REQUIRED MAINTENANCE TEST FLIGHT FOLLOWING REPLACEMENT OF BOTH ENGINES. WITNESSES STATED THAT THE TAKEOFF ROLL AND INITIAL CLIMB APPEARED NORMAL, BUT THAT AT ABOUT 500 FT AGL, THE AIRPLANE ENTERED A RIGHT BANK WHICH CONTINUED UNTIL THE WINGS WERE VERTICAL AND THE NOSE FELL THROUGH. AIRPLANE IMPACTED IN AN INVERTED STEEP NOSE DOWN ATTITUDE. EXAMINATION OF WRECKAGE REVEALED THAT THE RIGHT ENGINE HAD BEEN SECURED AND FEATHERED. SUBSEQUENT INVESTIGATION DID NOT REVEAL ANY EVIDENCE OF PRE-IMPACT FAILURE OR MALFUNCTION OF EITHER ENGINE OR ANY OF THE AIRFRAME SYSTEMS. ENGINE MOUNTING/RIGGING CONTINUITY COULD NOT BE ESTABLISHED DUE TO IMPACT DAMAGE. THE PILOT WAS A PRINCIPAL IN THE OPERATOR'S ORGANIZATION AND NOT ONE OF THE REGULAR LINE PILOTS. EVIDENCE INDICATED THAT THE GEAR WAS UP AND THAT THE LEFT SPOILER WAS DEPLOYED AT IMPACT. EMERG PROCEDURE TAUGHT IN TRANSITION TRAINING IS TO USE RUDDER TRIM AS SOON AS POSSIBLE AFTER ENG FAILURE TO PRECLUDE DEPLOYMENT OF SPOILERS. RUDDER TRIM FOUND IN NEUTRAL POSITION.

## Aircraft

- Registration: [N274MA](https://openairdocs.org/deregistered/N274MA-1991-03-13), registration cancelled 1991-03-13, S/N 786SA (OpenAirDocs)
- Reported make and model: MITSUBISHI MU-2B-60
- Registry model: [Mitsubishi MU-2B-60](https://openairdocs.org/model/mitsubishi-mu-2b-60) (registry code 5780460) (OpenAirDocs)
- Category: Airplane
- Serial number: 786SA
- Airframe hours: 6094
- Engines: GARRETT TPE-331-10 715 horsepower turbo prop
- Damage: Destroyed
- Flight: Part 91
- Operator: Corp. Aviation Services, Inc.
- Registered owner: Scope Leasing, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, February 22, 1991, 1 hours before
- Airport: TUL, Tulsa International, runway 35L, 6,101 × 150 ft

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 58; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 4,910 total, 445 in this make and model, 4,531 as pilot in command, 27 in the last 90 days, 11 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 20° at 13 knots
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 61 °F, dew point 30 °F
- Altimeter: 30.00 inHg

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19910222003339A](https://openairdocs.org/incident/19910222003339A), Feb 22, 1991: Mtsbsi MU2B60, Tulsa, OK, Destroyed, 3 fatal. Lost right engine on climbout. Feathered but below VMC,rolled. Crashed on highway. Engine heard surging on takeoff

## Other investigations on N274MA (1)

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 DEN83LA017](https://openairdocs.org/ntsb/DEN83LA017), Nov 11, 1982: Mitsubishi MU-2B-60 (N274MA), Englewood, CO, substantial 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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.