# NTSB OAK76DXQ05: Bell 47G3B1, N1358X, Mommoth Lakes, CA, July 8, 1975

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: July 8, 1975
- Place: Mommoth Lakes, CA · MOMMOTH LAKES, CA
- Location: 37.6244° N, 118.9884° W: Placed by OpenAirDocs: center of Mammoth Lakes, CA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=37.6244&lon=-118.9884&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report August 15, 1975
- Report: Brief approved by the director
- NTSB case key (mKey): 149459
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=OAK76DXQ05
- Page: https://openairdocs.org/ntsb/OAK76DXQ05

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-1844   75/7/8  NR.MOMMOTH LAKES,CA   BELL 47G3B1         CR-  0  0  1  COMMERCIAL                COMMERCIAL, AGE 29, 3277
        TIME - 0815                    N1358X              PX-  0  0  2  CTR PASSG-D               TOTAL HOURS, 483 IN TYPE,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            NOT INSTRUMENT RATED.
        DEPARTURE POINT             INTENDED DESTINATION
          MAMMOTH LAKES,CA            LOCAL
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           ENGINE FAILURE OR MALFUNCTION                            TAKEOFF: VERTICAL
           HARD LANDING                                             LANDING: POWER-OFF AUTOROTATIVE LANDING
        PROBABLE CAUSE(S)
           POWERPLANT - ENGINE STRUCTURE: VALVE ASSEMBLIES
           POWERPLANT - FUEL SYSTEM: CARBURETOR
           MISCELLANEOUS ACTS,CONDITIONS - MATERIAL FAILURE
        PARTIAL POWER LOSS - PARTIAL LOSS OF POWER - 1 ENGINE
        EMERGENCY CIRCUMSTANCES - FORCED LANDING OFF AIRPORT ON LAND
        REMARKS- LOW COMP NR 2 CYL VALVE SEAT LEAK. FAULTY CARB ALT COMPENSATOR.
```

## Aircraft

- Registration: [N1358X](https://openairdocs.org/deregistered/N1358X-2017-07-13), registration cancelled 2017-07-13, S/N 6569, built 1966 (OpenAirDocs)
- Reported make and model: BELL 47G3B1
- 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: Substantial damage

## 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 19750708020039A](https://openairdocs.org/incident/19750708020039A), Jul 8, 1975: Bell 47G3B1, Mommoth Lakes, CA, Substantial damage. Low comp nr 2 cyl valve seat leak. Faulty carb alt compensator.

## Other investigations on N1358X (4)

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 ATL90LA030](https://openairdocs.org/ntsb/ATL90LA030), Nov 25, 1989: Bell 47G-3B1 (N1358X), Ewell, AL, substantial damage. Probable cause: THE LOSS OF ENGINE POWER, FOR UNDETERMINED REASONS, AT LOW ALTITUDE DURING A PRACTICE AUTOROTATION. CONTRIBUTING TO THE ACCIDENT WAS THE INSTRUCTOR'S FAILURE TO PROPERLY PLAN THE DEMONSTRATED…
- [NTSB LAX78DUJ67](https://openairdocs.org/ntsb/LAX78DUJ67), Jun 11, 1978: Bell 47G3B1 (N1358X), Whiteriver, AZ, substantial damage
- [NTSB LAX76AL009](https://openairdocs.org/ntsb/LAX76AL009), Aug 5, 1975: Bell 47G3B1 (N1358X), Mt.Baldy, CA, substantial damage
- [NTSB LAX71DUJ06](https://openairdocs.org/ntsb/LAX71DUJ06), Jul 13, 1970: Bell 47G3B1 (N1358X), Elfrida, AZ, 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.

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