# Accident 20110623012719A: Hiller UH-12E, Hanford, CA, June 23, 2011

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: June 23, 2011, 04:30 local time
- Place: Hanford, CA
- Airport: N/A
- Damage: Substantial damage
- Phase of flight: Hover/Holding
- Operating rules: Agricultural (Part 137)
- Operator: MEZG
- Location: 36.3167° N, 119.6275° W: From the FAA
- Nearby events: https://openairdocs.org/map.md?lat=36.3167&lon=-119.6275&mi=10
- Aircraft: N99579, registered now (https://openairdocs.org/aircraft/N99579) (OpenAirDocs)
- Registry model: Hiller OH-23G (registry code 4360121, https://openairdocs.org/model/hiller-oh-23g) (OpenAirDocs)
- Reported make and model: HILLER UH-12E
- People aboard: 1
- Fatal injuries: 0
- Other injuries: 0
- NTSB investigation: [NTSB WPR11LA282](https://openairdocs.org/ntsb/WPR11LA282) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/20110623012719A

## Narrative

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

AT 0430 THE AIRCRAFT WAS BEING SERVICE AND REFUELING WHEN THE PILOT NOTICED EXCESS PLAY AND OIL LEAKING FROM THE TAIL ROTOR DRIVE COUPLING WHILE THE AIRCRAFT WAS AT IDLE. AS THE PILOT MOVED THE AICRAFT FROM THE SERVICE TRUCK TO THE GROUND FOR FURTHER MAINTENANCE THE AIRCRAFT LOST POWER TO THE TAIL ROTOR CAUSING THE AIRCRAFT TO ROTATE 4 TO 5 TIMES BEFORE IMPACTING THE GROUND.

## 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 WPR11LA282](https://openairdocs.org/ntsb/WPR11LA282), Jun 23, 2011: Hiller UH12E (N99579), Hanford, CA, substantial damage. Probable cause: The separation of the tail rotor drive gear shaft due to torsional fatigue of its threaded portion, which resulted in a loss of tail rotor control.

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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