# NTSB ANC74AA009: Hiller Acft UH12L4, N90470, Juneau, AK, July 17, 1973

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: July 17, 1973
- Place: Juneau, AK · JUNEAU, AK
- Location: 58.3019° N, 134.4197° W: Placed by OpenAirDocs: center of Juneau, AK, within about 29 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=58.3019&lon=-134.4197&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report November 21, 1973
- Report: Brief approved by the director
- NTSB case key (mKey): 188941
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC74AA009
- Page: https://openairdocs.org/ntsb/ANC74AA009

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
3-2982  73/7/17  NR.JUNEAU,ALAS        HILLER ACFT UH12L4  CR-  0  0  1  COMMERCIAL                COMMERCIAL, AGE 24, 2426
        TIME - 1000                    N90470              PX-  0  0  2  AIR TAXI-PASSG            TOTAL HOURS, 840 IN TYPE,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            NOT INSTRUMENT RATED.
        DEPARTURE POINT             INTENDED DESTINATION
         JUNEAU,ALAS                  LOCAL
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           PROPELLER/ROTOR FAILURE: MAIN ROTOR                      TAKEOFF: VERTICAL
           ROLL OVER                                                LANDING: LEVEL OFF/TOUCHDOWN
        PROBABLE CAUSE(S)
           ROTORCRAFT - TRANSMISSION ROTOR DRIVE SYSTEM: OTHER
           MISCELLANEOUS ACTS,CONDITIONS - MATERIAL FAILURE
           TERRAIN - ROUGH/UNEVEN
        EMERGENCY CIRCUMSTANCES - FORCED LANDING OFF AIRPORT ON LAND
         FIRE AFTER IMPACT
        REMARKS- TORSIONAL COUPLING HOUSING FAILED,ORIGIN UNDET.
```

## Aircraft

- Registration: [N90470](https://openairdocs.org/deregistered/N90470-1976-12-15), registration cancelled 1976-12-15, S/N 2510, built 1965 (OpenAirDocs)
- Reported make and model: HILLER ACFT UH12L4
- Registry model: [Hiller UH-12E4](https://openairdocs.org/model/hiller-uh-12e4) (registry code 4360127) (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 19730717038859A](https://openairdocs.org/incident/19730717038859A), Jul 17, 1973: Hiller UH12L4, Juneau, AK, Substantial damage. Torsional coupling housing failed,origin undet.

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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