# NTSB DEN81AA064: Mitsubishi MU-2B, N3ED, Riverton, WY, September 6, 1981

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Closed
- Date: September 6, 1981
- Place: Riverton, WY · RIVERTON, WY
- Location: 43.0263° N, 108.3813° W: Placed by OpenAirDocs: center of Riverton, WY, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=43.0263&lon=-108.3813&mi=10
- Phase of flight: [Uncontrolled descent](https://openairdocs.org/ntsb-phases/650) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 5 fatal
- Status: Completed, report June 15, 1982
- Report: Brief approved by the director
- NTSB case key (mKey): 122747
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN81AA064
- Page: https://openairdocs.org/ntsb/DEN81AA064

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-3667   81/9/6  NR.RIVERTON,WY        MITSUBISHI MU-2B    CR-  1  0  0  NONCOMMERCIAL             COMMERCIAL, AGE 46, 1500
        TIME - 0900                    N3ED                PX-  4  0  0  PLEASURE/PERSONAL TRANSP  TOTAL HOURS, 15 IN TYPE,
                                       DAMAGE-DESTROYED    OT-  0  0  0                            INSTRUMENT RATED.
        DEPARTURE POINT             INTENDED DESTINATION
          LANDER,WY                   NORTH PLATTE,NE
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           COLLISION WITH GROUND/WATER: UNCONTROLLED                IN FLIGHT: UNCONTROLLED DESCENT
        PROBABLE CAUSE(S)
           PILOT IN COMMAND - ATTEMPTED OPERATION W/KNOWN DEFICIENCIES IN EQUIPMENT
           MISCELLANEOUS ACTS,CONDITIONS - AIRFRAME ICE
        FACTOR(S)
           WEATHER - ICING CONDITIONS-INCLUDES SLEET,FREEZING RAIN,ETC.
        WEATHER BRIEFING - BRIEFED BY FLIGHT SERVICE PERSONNEL, BY PHONE
        WEATHER FORECAST - FORECAST SUBSTANTIALLY CORRECT
        SKY CONDITION                                            CEILING AT ACCIDENT SITE
          OVERCAST                                                  7000
        VISIBILITY AT ACCIDENT SITE                              PRECIPITATION AT ACCIDENT SITE
          5 OR OVER(UNLIMITED)                                     RAIN
        OBSTRUCTIONS TO VISION AT ACCIDENT SITE                  TEMPERATURE-F
          UNKNOWN/NOT REPORTED                                      12
        TYPE OF WEATHER CONDITIONS                               TYPE OF FLIGHT PLAN
          IFR                                                      IFR
         FIRE AFTER IMPACT
        REMARKS- PLT AWARE OF 4 DEFERRED MAINT DISCREPANCIES INVOLVING ANTI-ICE SYSTEM.MODERATE ICING FORECAST.
```

## Aircraft

- Registration: [N3ED](https://openairdocs.org/deregistered/N3ED-2012-09-25), registration cancelled 2012-09-25, S/N 101, built 1967 (OpenAirDocs)
- Reported make and model: MITSUBISHI MU-2B
- Registry model: [Mitsubishi MU-2B-10](https://openairdocs.org/model/mitsubishi-mu-2b-10) (registry code 5780406) (OpenAirDocs)
- Registry engine: [AiResearch TPE331 series](https://openairdocs.org/engine/airesearch-tpe331-series) (registry code 01514, turbo-prop) (OpenAirDocs)
- Category: Airplane
- Engines: turbo prop
- Damage: Destroyed

## 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 19810906055579A](https://openairdocs.org/incident/19810906055579A), Sep 6, 1981: Mtsbsi MU2B10, Riverton, WY, Destroyed, 4 fatal. Near vertical impact from a 9000 foot dive. Icing in area. Aircraft deicing system inoperative at departure.

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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