# NTSB DEN66A0020: Bell 47G3B1, N1135W, Commerce Cty, CO, September 9, 1965

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: September 9, 1965
- Place: Commerce Cty, CO · COMMERCE CTY, CO
- Location: 39.8083° N, 104.9339° W: Placed by OpenAirDocs: center of Commerce City, CO, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=39.8083&lon=-104.9339&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report November 8, 1965
- Report: Brief approved by the director
- NTSB case key (mKey): 176335
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN66A0020
- Page: https://openairdocs.org/ntsb/DEN66A0020

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
2-0575   65/9/9  NR.COMMERCE CTY COLO  BELL 47G3B1         CR-  0  0  2  INSTRUCTIONAL             COMMERCIAL, FL.INSTR.,
        TIME - 1600                    N1135W              PX-  0  0  0  CHECK                     AGE 33, 6311 TOTAL HOURS,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            4 IN TYPE, NOT INSTRUMENT
                                                                                                   RATED.
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           ENGINE FAILURE OR MALFUNCTION                            LANDING: FINAL APPROACH
           HARD LANDING                                             LANDING: POWER-OFF AUTOROTATIVE LANDING
        PROBABLE CAUSE(S)
           PILOT IN COMMAND - IMPROPER OPERATION OF POWERPLANT & POWERPLANT CONTROLS
           PILOT IN COMMAND - IMPROPER OPERATION OF FLIGHT CONTROLS
           PILOT IN COMMAND - FAILED TO MAINTAIN ADEQUATE ROTOR R.P.M.
        FACTOR(S)
           MISCELLANEOUS ACTS,CONDITIONS - SIMULATED CONDITIONS
           MISCELLANEOUS ACTS,CONDITIONS - DOWNWIND
        COMPLETE POWER LOSS - COMPLETE ENGINE FAILURE/FLAMEOUT-1 ENGINE
        EMERGENCY CIRCUMSTANCES - FORCED LANDING OFF AIRPORT ON LAND
        REMARKS- SIMULATED AUTOROTATIVE LANDING BECAME EMERGENCY DUE TO POWER FAILURE IN RECOVERY PHASE.
```

## Aircraft

- Registration: [N1135W](https://openairdocs.org/deregistered/N1135W-1981-06-06), registration cancelled 1981-06-06, S/N 2932 (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)
- Category: Helicopter
- Engines: reciprocating
- Damage: Substantial damage

## Other investigations on N1135W (3)

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 LAX78FA074](https://openairdocs.org/ntsb/LAX78FA074-139414), Sep 3, 1978: Bell 47G-3B (N1135W), Pasadena, CA, destroyed, 1 fatal
- [NTSB DEN75FTE21](https://openairdocs.org/ntsb/DEN75FTE21), Sep 6, 1974: Bell 47G3B1 (N1135W), Grand Valley, CO, substantial damage
- [NTSB SEA74DYG44](https://openairdocs.org/ntsb/SEA74DYG44), Jun 4, 1974: Bell 47G3B1 (N1135W), Stratford, WA, 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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