# NTSB CHI72FEC47: Bell 47G-5, N7979J, Detroit, MI, May 25, 1972

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: May 25, 1972
- Place: Detroit, MI · DETROIT, MI
- Location: 42.3314° N, 83.0458° W: Placed by OpenAirDocs: center of Detroit, MI, within about 7 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=42.3314&lon=-83.0458&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report February 14, 1973
- Report: Brief approved by the director
- NTSB case key (mKey): 167038
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI72FEC47
- Page: https://openairdocs.org/ntsb/CHI72FEC47

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-1897  72/5/25    DETROIT,MICH        BELL 47G-5          CR-  0  0  2  MISCELLANEOUS             COMMERCIAL, AGE 33, 900
        TIME - 2230                    N7979J              PX-  0  0  0  POLICE PATROL             TOTAL HOURS, 190 IN TYPE,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            NOT INSTRUMENT RATED.
        NAME OF AIRPORT - DETROIT CITY
        DEPARTURE POINT             INTENDED DESTINATION
          DETROIT,MICH                LOCAL
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           PROPELLER/ROTOR FAILURE: TAIL ROTOR                      IN FLIGHT: NORMAL CRUISE
           HARD LANDING                                             LANDING: POWER-OFF AUTOROTATIVE LANDING
        PROBABLE CAUSE(S)
           ROTORCRAFT - TRANSMISSION ROTOR DRIVE SYSTEM: TAIL ROTOR GEAR BOX
           MISCELLANEOUS ACTS,CONDITIONS - IMPROPERLY SECURED
           MISCELLANEOUS ACTS,CONDITIONS - IMPROPERLY INSTALLED
           PERSONNEL - MAINTENANCE,SERVICING,INSPECTION: INADEQUATE MAINTENANCE AND INSPECTION
           MISCELLANEOUS - EVASIVE MANEUVER TO AVOID COLLISION
        EMERGENCY CIRCUMSTANCES - FORCED LANDING ON AIRPORT/SEAPLANE BASE/HELIPT.
        REMARKS- T/R SYS FAILED DUE OMISSION OF RETAINING NUT ON PITCH CHNG MECHANISM. HAD TO AVOID PARKED ACFT.
```

## Aircraft

- Registration: [N7979J](https://openairdocs.org/deregistered/N7979J-1985-08-01), registration cancelled 1985-08-01, S/N 25050 (OpenAirDocs)
- Reported make and model: BELL 47G-5
- Registry model: [Bell 47G-5](https://openairdocs.org/model/bell-47g-5) (registry code 1181032) (OpenAirDocs)
- Category: Helicopter
- Engines: reciprocating
- Damage: Substantial damage
- Airport: Detroit City

## Other investigations on N7979J (1)

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 CHI72FEC28](https://openairdocs.org/ntsb/CHI72FEC28), Feb 24, 1972: Bell 47-G5 (N7979J), Detroit, MI, 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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