# NTSB IAD74D1A01: Bell 47G4A, N21MP, Washington, DC, July 4, 1974

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Closed
- Date: July 4, 1974
- Place: Washington, DC · WASHINGTON, DC
- Location: 38.8951° N, 77.0364° W: Placed by OpenAirDocs: center of Washington, DC, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=38.8951&lon=-77.0364&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor, 1 uninjured
- Status: Completed, report August 7, 1974
- Report: Brief approved by the director
- NTSB case key (mKey): 128155
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=IAD74D1A01
- Page: https://openairdocs.org/ntsb/IAD74D1A01

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-1860   74/7/4    WASHINGTON,DC       BELL 47G4A          CR-  0  0  1  MISCELLANEOUS             COMMERCIAL, FL.INSTR.,
        TIME - 1315                    N21MP               PX-  0  0  1  POLICE PATROL             AGE 39, 1563 TOTAL HOURS,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            1221 IN TYPE, NOT
                                                                                                   INSTRUMENT RATED.
        NAME OF AIRPORT - ANACOSTIA
        DEPARTURE POINT             INTENDED DESTINATION
          WASHINGTON,DC               LOCAL
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           ENGINE FAILURE OR MALFUNCTION                            IN FLIGHT: OTHER
           HARD LANDING                                             LANDING: POWER-ON LANDING
        PROBABLE CAUSE(S)
           POWERPLANT - MISCELLANEOUS: POWERPLANT FAILURE FOR UNDETERMINED REASONS
           PILOT IN COMMAND - IMPROPER IN-FLIGHT DECISIONS OR PLANNING
           PILOT IN COMMAND - FAILED TO MAINTAIN ADEQUATE ROTOR R.P.M.
        PARTIAL POWER LOSS - PARTIAL LOSS OF POWER - 1 ENGINE
        EMERGENCY CIRCUMSTANCES - PRECAUTIONARY LANDING OFF AIRPORT
                                  PROP/ENGINE VIBRATION
                                  SUSPECTED MECHANICAL DISCREPANCY
        REMARKS- APCH MADE TO 10FT AGL.EXPERIENCED 2ND PWR LOSS,UN MNTN RPM.
```

## Aircraft

- Registration: [N21MP](https://openairdocs.org/aircraft/N21MP), registered now, S/N 7755, built 1971 (OpenAirDocs)
- Reported make and model: BELL 47G4A
- Registry model: [Bell 47G-4A](https://openairdocs.org/model/bell-47g-4a) (registry code 1181031) (OpenAirDocs)
- Registry engine: [Lycoming VO-540 series](https://openairdocs.org/engine/lycoming-vo-540-series) (registry code 41534, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Engines: reciprocating
- Damage: Substantial damage
- Airport: Anacostia

## 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 19740704019829A](https://openairdocs.org/incident/19740704019829A), Jul 4, 1974: Bell 47G4A, Washington, DC, Substantial damage. Apch made to 10FT AGL.experienced 2nd pwr loss,un mntn RPM.

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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