# Accident 19950901027639A: Hiller UH12E, Dos Palos, CA, September 1, 1995

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: September 1, 1995, 08:30 local time
- Place: Dos Palos, CA
- Damage: Substantial damage
- Phase of flight: Pwr Off Vert Land/Autorotate
- Operating rules: Agricultural (Part 137)
- Location: 37.0709° N, 120.6309° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=37.0709&lon=-120.6309&mi=10
- Aircraft: N4027D, registered now (https://openairdocs.org/aircraft/N4027D) (OpenAirDocs)
- Registry model: Hiller UH-12E (registry code 4360122, https://openairdocs.org/model/hiller-uh-12e) (OpenAirDocs)
- Reported make and model: HILLER UH12E
- Reported engine: LYC VO540C2A
- People aboard: 1
- Fatal injuries: 0
- Pilot flight hours: 8,500 total, 3,003 in this make and model, 300 in the last 90 days
- NTSB investigation: [NTSB LAX95LA318](https://openairdocs.org/ntsb/LAX95LA318) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19950901027639A

## Narrative

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

DURING SPRAY RUN VIBRATION SEVERE YAW AND SPIN. IMPACTED HARD. HAD LOST A TAIL ROTOR BLADE. TT BAR FATIGUE FAILURE.

## 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 LAX95LA318](https://openairdocs.org/ntsb/LAX95LA318), Sep 1, 1995: Hiller UH-12E (N4027D), Dos Palos, CA, substantial damage. Probable cause: the fatigue failure of the tail rotor tension torsion bar plates.

## Other reports on N4027D (3)

Matched to the same aircraft by N-number and date.

- [Accident 19830107000309A](https://openairdocs.org/incident/19830107000309A), Jan 7, 1983: Hiller UH12E (N4027D), Vacaville, CA, Substantial damage. Rotor blades struck a powerline when helicopter lifted from a levee. Pilot landed ok but slid off into a ditch.
- [Incident 19810403024639I](https://openairdocs.org/incident/19810403024639I), Apr 3, 1981: Hiller UH12E (N4027D), Huron, CA, Minor damage. Main rotor blade skin separated and demolished tail rotor and transmission. Pilot landed ok.
- [Accident 19790427007179A](https://openairdocs.org/incident/19790427007179A), Apr 27, 1979: Hiller UH12E (N4027D), Gustine, CA, Substantial damage. Pilot hit a wire while spraying agricultural chemicals.

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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