# NTSB DEN66A0084: Hiller UH-12E, N9754C, Lonetree, WY, May 21, 1966

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Closed
- Date: May 21, 1966
- Place: Lonetree, WY · LONETREE, WY
- Location: 41.0544° N, 110.1540° W: Placed by OpenAirDocs: center of Lonetree, WY, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=41.0544&lon=-110.1540&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 18, 1966
- Report: Brief approved by the director
- NTSB case key (mKey): 172411
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN66A0084
- Page: https://openairdocs.org/ntsb/DEN66A0084

## NTSB brief

```
----------------------------------------------------------------------------------------------------------------------------
 FILE    DATE          LOCATION          AIRCRAFT DATA       INJURIES       FLIGHT                        PILOT DATA
                                                               F  S M/N     PURPOSE
----------------------------------------------------------------------------------------------------------------------------
2-0329  66/5/21    LONETREE WYO        HILLER UH-12E       CR-  0  0  1  COMMERCIAL                COMMERCIAL, AGE 51, 3520
        TIME - 1730                    N9754C              PX-  0  0  0  AERIAL APPLICATION        TOTAL HOURS, 368 IN TYPE,
                                       DAMAGE-SUBSTANTIAL  OT-  0  0  0                            NOT INSTRUMENT RATED.
        TYPE OF ACCIDENT                                         PHASE OF OPERATION
           COLLISION WITH GROUND/WATER: CONTROLLED                  IN FLIGHT: PROCEDURE TURNAROUND
        PROBABLE CAUSE(S)
           PILOT IN COMMAND - MISJUDGED ALTITUDE
        FACTOR(S)
           WEATHER - HIGH DENSITY ALTITUDE
           MISCELLANEOUS ACTS,CONDITIONS - JETTISONED LOAD
        SKY CONDITION                                            CEILING AT ACCIDENT SITE
          OVERCAST                                                  10000
        VISIBILITY AT ACCIDENT SITE                              PRECIPITATION AT ACCIDENT SITE
          5 OR OVER(UNLIMITED)                                     NONE
        OBSTRUCTIONS TO VISION AT ACCIDENT SITE                  TEMPERATURE-F
          NONE                                                      68
        WIND DIRECTION-DEGREES                                   WIND VELOCITY-KNOTS
          225                                                       8
        TYPE OF WEATHER CONDITIONS                               TYPE OF FLIGHT PLAN
          VFR                                                      NONE
         SPECIAL DATA
          TOTAL HOURS IN CROP CONTROL - UNKNOWN/NOT REPORTED       KIND OF OPERATION - DEFOLIATION (LIQUID)
          KIND OF CROP - MESQUITE                                  TYPE OF CHEMICAL USED - LIQUID CHEMICAL-NONTOXIC
          PILOT' S SEAT BELT -FASTENED-PROPERLY                    GLOVES - NOT USED
          GOGGLES - NOT USED                                       CRASH HELMET - AVAILABLE-NOT USED
          COCKPIT CRASHPAD - NOT INSTALLED                         CRASH BAR - NOT INSTALLED
          TANK/HOPPER-LOCATION - SIDES                             TERRAIN-TYPE -ROLLING
          ELEVATION-AREA BEING TREATED-FEET -  7500                              HILLY
          SWATH RUN-HOW FLOWN - DOWNWIND                           PROCEDURE TURNAROUND - THIRD 1/3 TURN
```

## Aircraft

- Registration: [N9754C](https://openairdocs.org/aircraft/N9754C), registered now, S/N 2149, built 1961 (OpenAirDocs)
- Reported make and model: HILLER UH-12E
- Registry model: [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e) (registry code 4360122) (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

## Other investigations on N9754C (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 CEN10CA362](https://openairdocs.org/ntsb/CEN10CA362), Jun 25, 2010: Hiller UH-12E (N9754C), Grand Junction, CO, substantial damage. Probable cause: The total loss of engine power for undetermined reasons.
- [NTSB DEN67A0002](https://openairdocs.org/ntsb/DEN67A0002-171116), Jul 7, 1966: Hiller UH12E (N9754C), Greybull, WY, 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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