# NTSB UNK64X4172: Bell 47G2, N5193B, Pomona, CA, September 26, 1964

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: September 26, 1964
- Place: Pomona, CA · POMONA, CA
- Location: 34.0585° N, 117.7611° W: Placed by OpenAirDocs: center of Pomona, CA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=34.0585&lon=-117.7611&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report January 26, 1965
- Report: Brief approved by the director
- NTSB case key (mKey): 184141
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=UNK64X4172
- Page: https://openairdocs.org/ntsb/UNK64X4172

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
2-0778  64/9/26    POMONA CALIF        BELL 47G2           CR-  0  0  1  COMMERCIAL                COMMERCIAL, FL.INSTR.,
        TIME - 1251                    N5193B              PX-  0  0  1  AIR TAXI-PASSG            AGE 38, 3500 TOTAL HOURS,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            2200 IN TYPE, NOT
                                                                                                   INSTRUMENT RATED.
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           COLLISION WITH GROUND/WATER: UNCONTROLLED                LANDING: FINAL APPROACH
        PROBABLE CAUSE(S)
           PERSONNEL - MAINTENANCE,SERVICING,INSPECTION: IMPROPER MAINTENANCE (MAINTENANCE PERSONNEL)
           PERSONNEL - MAINTENANCE,SERVICING,INSPECTION: INADEQUATE INSPECTION OF AIRCRAFT (MAINTENANCE PERSONNEL)
           ROTORCRAFT - TRANSMISSION ROTOR DRIVE SYSTEM: TAIL ROTOR DRIVE SHAFT ASSEMBLY
           MISCELLANEOUS ACTS,CONDITIONS - IMPROPERLY INSTALLED
        EMERGENCY CIRCUMSTANCES - FORCED LANDING OFF AIRPORT ON WATER
                                  DIRECTIONAL CONTROL PROBLEM
        REMARKS- LOSS OF ANTI TORQUE CONTROL -FORWARD SLEEVE LOCK NUT OF TAIL ROTOR DRIVE SHAFT NOT SECURED
```

## Aircraft

- Registration: [N5193B](https://openairdocs.org/deregistered/N5193B-2008-03-03), registration cancelled 2008-03-03, S/N 2174, built 1958 (OpenAirDocs)
- Reported make and model: BELL 47G2
- Registry model: [Bell 47G-2](https://openairdocs.org/model/bell-47g-2) (registry code 1181008) (OpenAirDocs)
- Registry engine: [Lycoming VO-435 series](https://openairdocs.org/engine/lycoming-vo-435-series) (registry code 41525, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Engines: reciprocating
- Damage: Substantial damage

## Other investigations on N5193B (6)

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 FTW02LA264](https://openairdocs.org/ntsb/FTW02LA264), Sep 25, 2002: Bell 47G-2 (N5193B), Edmondson, AR, destroyed, 1 fatal. Probable cause: The pilot's failure to maintain clearance from the high voltage power lines.
- [NTSB CHI95LA003](https://openairdocs.org/ntsb/CHI95LA003), Oct 3, 1994: Bell 47G2 (N5193B), Decatur, IL, substantial damage. Probable cause: the failure of the roller springs in the freewheeling unit of the transmission which caused the unit to disengage.
- [NTSB NYC70DFM16](https://openairdocs.org/ntsb/NYC70DFM16), Jun 8, 1970: Bell 47G2 (N5193B), Danbury, CT, substantial damage
- [NTSB LAX70F0025](https://openairdocs.org/ntsb/LAX70F0025), Sep 4, 1968: Bell 47G-2 (N5193B), Hollywood, CA, destroyed, 2 fatal
- [NTSB LAX68A0022](https://openairdocs.org/ntsb/LAX68A0022), Aug 18, 1967: Bell 47G-2 (N5193B), Camarillo, CA, substantial damage
- [NTSB UNK64X1672](https://openairdocs.org/ntsb/UNK64X1672), May 8, 1964: Bell 47G2 (N5193B), Glendora, CA, 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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