# NTSB ANC82DAG01: Enstrom F-28C, N51727, Big Lake, AK, October 1, 1981

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: October 1, 1981
- Place: Big Lake, AK · BIG LAKE, AK
- Location: 61.5450° N, 149.8180° W: Placed by OpenAirDocs: center of Big Lake, AK, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=61.5450&lon=-149.8180&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report October 19, 1981
- Report: Brief approved by the director
- NTSB case key (mKey): 123696
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC82DAG01
- Page: https://openairdocs.org/ntsb/ANC82DAG01

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-1859   81/10/1 NR.BIG LAKE,AK        ENSTROM F-28C       CR-  0  0  1  NONCOMMERCIAL             COMMERCIAL, AGE 29, 2049
        TIME - 0940                    N51727              PX-  0  0  0  OTHER                     TOTAL HOURS, 540 IN TYPE,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            INSTRUMENT RATED.
        DEPARTURE POINT             INTENDED DESTINATION
          FLAT LAKE,AK                LOCAL
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           PROPELLER/ROTOR FAILURE: MAIN ROTOR                      IN FLIGHT: HOVERING
           HARD LANDING                                             LANDING: POWER-OFF AUTOROTATIVE LANDING
        PROBABLE CAUSE(S)
           ROTORCRAFT - TRANSMISSION ROTOR DRIVE SYSTEM: SPRAG SYSTEM
           MISCELLANEOUS ACTS,CONDITIONS - MATERIAL FAILURE
        EMERGENCY CIRCUMSTANCES - FORCED LANDING OFF AIRPORT ON LAND
        REMARKS- NONCOMMERCIAL SLING LOADING LUMBER.SPRAG CLUTCH,PN CL-40526-7,FAILED.
```

## Aircraft

- Registration: [N51727](https://openairdocs.org/deregistered/N51727-2018-01-09), registration cancelled 2018-01-09, S/N 393, built 1977 (OpenAirDocs)
- Reported make and model: ENSTROM F-28C
- Registry model: [Enstrom F-28C](https://openairdocs.org/model/enstrom-f-28c) (registry code 3300407) (OpenAirDocs)
- Registry engine: [Lycoming HIO-360 series](https://openairdocs.org/engine/lycoming-hio-360-series) (registry code 41524, 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 19811001064619A](https://openairdocs.org/incident/19811001064619A), Oct 1, 1981: Enstrm F28C, Big Lake, AK, Substantial damage. Rotor drive clutch failed while lifting a sling load. Made hard autorotation landing next to load. Pn CL405267.

## Other investigations on N51727 (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 WPR12LA111](https://openairdocs.org/ntsb/WPR12LA111), Feb 20, 2012: Enstrom F28 (N51727), Kalispell, MT, substantial damage. Probable cause: A total loss of engine power for reasons that could not be determined because postaccident examination did not reveal any anomalies that would have precluded normal operation.
- [NTSB SEA77DYK20](https://openairdocs.org/ntsb/SEA77DYK20), Jul 22, 1977: Enstrom F28C (N51727), Medford, WA, 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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