# Accident 19910824036649A: Hiller UH12D, Sparks, NV, August 24, 1991

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: August 24, 1991, 19:50 local time
- Place: Sparks, NV
- Damage: Substantial damage
- Phase of flight: Pwr Off Vert Land/Autorotate
- Operating rules: General operating rules (Part 91)
- Location: 39.5999° N, 119.6906° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=39.5999&lon=-119.6906&mi=10
- Aircraft: N100HH, a cancelled registration (https://openairdocs.org/deregistered/N100HH-2018-05-30) (OpenAirDocs)
- Registry model: Hiller UH-12D (registry code 4360118, https://openairdocs.org/model/hiller-uh-12d) (OpenAirDocs)
- Registry engine: Lycoming VO-435 series (registry code 41525, https://openairdocs.org/engine/lycoming-vo-435-series) (OpenAirDocs)
- Reported make and model: HILLER UH12D
- Reported engine: LYC VO435A1C
- People aboard: 1
- Fatal injuries: 0
- Pilot flight hours: 265 total, 5 in the last 90 days
- NTSB investigation: [NTSB LAX91LA369](https://openairdocs.org/ntsb/LAX91LA369) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19910824036649A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

DETECTED VIBRATION. AUTOROTATED TO ROUGH SHALE ROCK. CHOPPED TAILBOOM. BEARING ON TAIL ROTOR SHAFT HEAT DAMAGE.

## The NTSB's investigation of this event (1)

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 LAX91LA369](https://openairdocs.org/ntsb/LAX91LA369), Aug 25, 1991: Hiller UH12D (N100HH), Sparks, NV, substantial damage. Probable cause: THE ENCOUNTER WITH ROUGH, UNSUITABLE TERRAIN DURING A PRECAUTIONARY LANDING. CONTRIBUTING TO THE ACCIDENT WAS THE PILOT'S DECISION TO MAKE AN AUTOROTATION AFTER ENCOUNTERING AN AIRFRAME VIBRATION.

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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