# NTSB SEA73FTA06: Bell 47G-3B, N204Z, Billings, MT, April 23, 1973

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: April 23, 1973
- Place: Billings, MT · BILLINGS, MT
- Location: 45.7833° N, 108.5007° W: Placed by OpenAirDocs: center of Billings, MT, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=45.7833&lon=-108.5007&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report June 7, 1973
- Report: Brief approved by the director
- NTSB case key (mKey): 190773
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA73FTA06
- Page: https://openairdocs.org/ntsb/SEA73FTA06

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-0903  73/4/23  NR.BILLINGS,MONT      BELL 47G-3B         CR-  0  0  2  COMMERCIAL                COMMERCIAL, AGE 25, 1559
        TIME - 1130                    N204Z               PX-  0  0  0  POWER/PIPELINE            TOTAL HOURS, 145 IN TYPE,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            NOT INSTRUMENT RATED.
        DEPARTURE POINT             INTENDED DESTINATION
         BILLINGS,MONT                LOCAL
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           ENGINE FAILURE OR MALFUNCTION                            IN FLIGHT: NORMAL CRUISE
           ROLL OVER                                                LANDING: POWER-OFF AUTOROTATIVE LANDING
        PROBABLE CAUSE(S)
           POWERPLANT - ENGINE STRUCTURE: MASTER AND CONNECTING RODS
           MISCELLANEOUS ACTS,CONDITIONS - MATERIAL FAILURE
           TERRAIN - ROUGH/UNEVEN
        COMPLETE POWER LOSS - COMPLETE ENGINE FAILURE/FLAMEOUT-1 ENGINE
        EMERGENCY CIRCUMSTANCES - FORCED LANDING OFF AIRPORT ON LAND
        REMARKS- NR 5 CONROD BOLTS FAILED.LND ON 30 DEG SLOPE IN WOODED CLEARING. PIPELINE SURVEILLANCE FLT.
```

## Aircraft

- Registration: [N204Z](https://openairdocs.org/deregistered/N204Z-2002-10-04), registration cancelled 2002-10-04, S/N 3449, built 1961 (OpenAirDocs)
- Reported make and model: BELL 47G-3B
- Registry model: [Bell 47G-3B](https://openairdocs.org/model/bell-47g-3b) (registry code 1181026) (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 19730423009869A](https://openairdocs.org/incident/19730423009869A), Apr 23, 1973: Bell 47G3B, Billings, MT, Substantial damage. Nr 5 conrod bolts failed. Lnd on 30 deg slope in wooded clearing. Pipeline surveillance flt.

## Other investigations on N204Z (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 DEN83LA002](https://openairdocs.org/ntsb/DEN83LA002), Oct 5, 1982: Bell 47G3B (N204Z), Nr. Englewood, CO, destroyed
- [NTSB SEA72FTA17](https://openairdocs.org/ntsb/SEA72FTA17), Apr 27, 1972: Bell 47G-3B (N204Z), Harlowton, MT, substantial damage
- [NTSB MIA69F0341](https://openairdocs.org/ntsb/MIA69F0341), Jan 18, 1969: Bell 47G-3B (N204Z), Kingsport, TN, 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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