# NTSB ANC67A0057: Bell 47J-2A, N3070G, Tyonek, AK, April 13, 1967

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Closed
- Date: April 13, 1967
- Place: Tyonek, AK · TYONEK, AK
- Location: 61.0681° N, 151.1369° W: Placed by OpenAirDocs: center of Tyonek, AK, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=61.0681&lon=-151.1369&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 3 serious
- Status: Completed, report March 7, 1968
- Report: Brief approved by the director
- NTSB case key (mKey): 117896
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC67A0057
- Page: https://openairdocs.org/ntsb/ANC67A0057

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
2-1033  67/4/13  NR.TYONEK,ALAS        BELL 47J-2A         CR-  0  1  0  COMMERCIAL                COMMERCIAL, FL.INSTR.,
        TIME - 1430                    N3070G              PX-  0  2  0  CTR PASSG-D               AGE 26, 2575 TOTAL HOURS,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            1095 IN TYPE, NOT
                                                                                                   INSTRUMENT RATED.
        NAME OF AIRPORT - MOBIL HELIPORT
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           PROPELLER/ROTOR FAILURE: MAIN ROTOR                      TAKEOFF: INITIAL CLIMB
           HARD LANDING                                             LANDING: LEVEL OFF/TOUCHDOWN
        PROBABLE CAUSE(S)
           ROTORCRAFT - TRANSMISSION ROTOR DRIVE SYSTEM: CLUTCH ASSEMBLY
           ROTORCRAFT - TRANSMISSION ROTOR DRIVE SYSTEM: FREE WHEEL UNIT
        EMERGENCY CIRCUMSTANCES - FORCED LANDING OFF AIRPORT ON WATER
        REMARKS- LOSS OF POWER COUPLING TO MAIN ROTOR DUE TO SLIPPAGE OF FREE WHEELING UNIT.CAUSE NOT DETERMINED.
```

## Aircraft

- Registration: [N3070G](https://openairdocs.org/deregistered/N3070G-1969-06-30), registration cancelled 1969-06-30, S/N 3112, built 1964 (OpenAirDocs)
- Reported make and model: BELL 47J-2A
- Registry model: [Bell 47J-2A](https://openairdocs.org/model/bell-47j-2a) (registry code 1181106) (OpenAirDocs)
- Category: Helicopter
- Engines: reciprocating
- Damage: Substantial damage
- Airport: Mobil Heliport

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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