# NTSB SEA69A0012: Bell 47G-3B, N8491E, Twin Falls, ID, August 13, 1968

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: August 13, 1968
- Place: Twin Falls, ID · TWIN FALLS, ID
- Location: 42.5641° N, 114.4609° W: Placed by OpenAirDocs: center of Twin Falls, ID, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=42.5641&lon=-114.4609&mi=10
- Phase of flight: [Emergency descent](https://openairdocs.org/ntsb-phases/600) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report March 18, 1969
- Report: Brief approved by the director
- NTSB case key (mKey): 108700
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA69A0012
- Page: https://openairdocs.org/ntsb/SEA69A0012

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-4673  68/8/13  NR.TWIN FALLS,ID      BELL 47G-3B         CR-  0  0  2  INSTRUCTIONAL             COMMERCIAL, AGE 24, 238
        TIME - 0922                    N8491E              PX-  0  0  0  CHECK                     TOTAL HOURS, 54 IN TYPE,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            NOT INSTRUMENT RATED.
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           ENGINE FAILURE OR MALFUNCTION                            IN FLIGHT: AUTOROTATIVE DESCENT
           HARD LANDING                                             LANDING: POWER-OFF AUTOROTATIVE LANDING
        PROBABLE CAUSE(S)
           MISCELLANEOUS ACTS,CONDITIONS - SIMULATED CONDITIONS
           MISCELLANEOUS ACTS,CONDITIONS - ENGINE LOADED UP
           CHECK PILOT - IMPROPER OPERATION OF POWERPLANT & POWERPLANT CONTROLS
           CHECK PILOT - FAILED TO FOLLOW APPROVED PROCEDURES,DIRECTIVES,ETC.
           CHECK PILOT - IMPROPER OPERATION OF FLIGHT CONTROLS
        FACTOR(S)
           PILOT IN COMMAND - CONTROL INTERFERENCE
        COMPLETE POWER LOSS - COMPLETE ENGINE FAILURE/FLAMEOUT-1 ENGINE
        EMERGENCY CIRCUMSTANCES - FORCED LANDING OFF AIRPORT ON LAND
        REMARKS- ABRUPT THROTTLE REDUCTION WHEN FLT MANUAL STATES RETARD THROTTE SLOWLY,MAINT 2000 RPM.
```

## Aircraft

- Registration: [N8491E](https://openairdocs.org/deregistered/N8491E-2018-01-26), registration cancelled 2018-01-26, S/N 2712, 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

## Other investigations on N8491E (2)

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 SEA97LA112](https://openairdocs.org/ntsb/SEA97LA112), May 15, 1997: Bell 47G-3B (N8491E), Snohomish, WA, substantial damage. Probable cause: the pilot's encounter with of a loss of tail rotor effectiveness (LTE) situation, and his subsequent inadequate remedial action. Related factors included: wind conditions that were conducive to an…
- [NTSB UNK64X2017](https://openairdocs.org/ntsb/UNK64X2017), May 30, 1964: Bell 47G3B (N8491E), Muldoon, ID, 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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