# NTSB SEA67A0002: Bell 47-G3B, N8509F, Clinton, MT, July 14, 1966

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Closed
- Date: July 14, 1966
- Place: Clinton, MT · CLINTON, MT
- Location: 46.7718° N, 113.7205° W: Placed by OpenAirDocs: center of Clinton, MT, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=46.7718&lon=-113.7205&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 3 serious
- Status: Completed, report March 1, 1967
- Report: Brief approved by the director
- NTSB case key (mKey): 171661
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA67A0002
- Page: https://openairdocs.org/ntsb/SEA67A0002

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
2-0559  66/7/14    CLINTON MONT        BELL 47-G3B         CR-  0  1  0  NONCOMMERCIAL             COMMERCIAL, FL.INSTR.,
        TIME - 0915                    N8509F              PX-  0  2  0  AERIAL SURVEY             AGE 47, 1766 TOTAL HOURS,
                                       DAMAGE-DESTROYED    OT-  0  0  0                            266 IN TYPE, NOT
                                                                                                   INSTRUMENT RATED.
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           ENGINE FAILURE OR MALFUNCTION                            TAKEOFF: VERTICAL
           HARD LANDING                                             IN FLIGHT: UNCONTROLLED DESCENT
        PROBABLE CAUSE(S)
           POWERPLANT - EXHAUST SYSTEM: EXTERNAL SUPERCHARGER
           MISCELLANEOUS ACTS,CONDITIONS - WARPED
           POWERPLANT - EXHAUST SYSTEM: GASKET
           MISCELLANEOUS ACTS,CONDITIONS - MATERIAL FAILURE
           POWERPLANT - EXHAUST SYSTEM: CLAMPS
           MISCELLANEOUS ACTS,CONDITIONS - LOOSE,PART/FITTING
        PARTIAL POWER LOSS - PARTIAL LOSS OF POWER - 1 ENGINE
         FIRE AFTER IMPACT
        REMARKS- MINING EXPLORATION FLIGHT.DENSITY ALT.8850 FT.EXHAUST GAS LEAKAGE CAUSED REDUCED TURBOCHGER EFFNCY
```

## Aircraft

- Registration: [N8509F](https://openairdocs.org/aircraft/N8509F), registered now, S/N 3381 (OpenAirDocs)
- Reported make and model: BELL 47-G3B
- Registry model: [Bell 47G-3B-1](https://openairdocs.org/model/bell-47g-3b-1) (registry code 1181028) (OpenAirDocs)
- Registry engine: [Lycoming TVO-435-GIA](https://openairdocs.org/engine/lycoming-tvo-435-gia) (registry code 41526, turbo-prop) (OpenAirDocs)
- Category: Helicopter
- Engines: reciprocating
- Damage: Destroyed

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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