# NTSB NYC76AN044: Bell 47J-2, N3939B, Conshocken, PA, October 22, 1975

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: October 22, 1975
- Place: Conshocken, PA · CONSHOCKEN, PA
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report January 18, 1976
- Report: Brief approved by the director
- NTSB case key (mKey): 151482
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC76AN044
- Page: https://openairdocs.org/ntsb/NYC76AN044

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-3781  75/10/22   CONSHOCKEN,PA       BELL 47J-2          CR-  0  0  1  MISCELLANEOUS             COMMERCIAL, FL.INSTR.,
        TIME - 1732                    N3939B              PX-  0  0  2  HIGHWAY TRAFFIC ADVISORY  AGE 28, 4506 TOTAL HOURS,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            752 IN TYPE, INSTRUMENT
                                                                                                   RATED.
        DEPARTURE POINT             INTENDED DESTINATION
          PHILADELPHIA,PA             LOCAL
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           ENGINE FAILURE OR MALFUNCTION                            IN FLIGHT: NORMAL CRUISE
           COLLISION WITH GROUND/WATER: CONTROLLED                  LANDING: POWER-OFF AUTOROTATIVE LANDING
        PROBABLE CAUSE(S)
           POWERPLANT - ENGINE STRUCTURE: MASTER AND CONNECTING RODS
           MISCELLANEOUS ACTS,CONDITIONS - FATIGUE FRACTURE
           MISCELLANEOUS ACTS,CONDITIONS - OIL EXHAUSTION-ENGINE LUBRICATION SYSTEM
        FACTOR(S)
           TERRAIN - ROUGH/UNEVEN
        COMPLETE POWER LOSS - COMPLETE ENGINE FAILURE/FLAMEOUT-1 ENGINE
        EMERGENCY CIRCUMSTANCES - FORCED LANDING OFF AIRPORT ON LAND
        REMARKS- NR 5 CONNECTING ROD (P/N LW-13422) FATIGUE FRACTURED AND BROKE A HOLE IN CRANKCASE.DRAINED ENG OIL
```

## Aircraft

- Registration: [N3939B](https://openairdocs.org/deregistered/N3939B-2018-04-05), registration cancelled 2018-04-05, S/N 2846, built 1963 (OpenAirDocs)
- Reported make and model: BELL 47J-2
- Registry model: [Bell 47J-2](https://openairdocs.org/model/bell-47j-2) (registry code 1181104) (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

## 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 19751022041339A](https://openairdocs.org/incident/19751022041339A), Oct 22, 1975: Bell 47J2, Conshocken, PA, Substantial damage. Nr 5 connecting rod (p/n LW-13422) fatigue fractured and broke a hole in crankcase. Drained eng oil

## Other investigations on N3939B (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 NYC67A0030](https://openairdocs.org/ntsb/NYC67A0030), Aug 17, 1966: Bell 47J-2 (N3939B), Dedham, MA, 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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