# N99579: Hiller OH-23G

- Status: Sale reported, pending cancellation
- Airframe: [Hiller OH-23G](https://openairdocs.org/model/hiller-oh-23g) (registry code 4360121, 4 seats)
- Data sheets: [TCDS 4H11](https://openairdocs.org/tcds/4H11) (Siam Hiller Holdings Inc.) (OpenAirDocs)
- Serial number: 64-15224
- Type: Rotorcraft
- Engine type: Reciprocating
- Mode S code: ADE8A5
- Location: [Geyser, MT](https://openairdocs.org/faa-place/MT/Geyser)
- Owner type: Individual
- Owner's area on the map: 47.2862° N, 110.4500° W: Placed by OpenAirDocs at the center of ZIP code 59447, within about 11 miles (OpenAirDocs). The owner's mailing address, not where the aircraft is based
- FAA registry: https://registry.faa.gov/AircraftInquiry/Search/NNumberResult?nNumberTxt=99579
- Page: https://openairdocs.org/aircraft/N99579

From the FAA registry file of October 24, 2026. ADs below are matched by the registry's airframe and engine model codes. They may apply; each AD's applicability can narrow it by serial number, part number or installed equipment. This is not a compliance determination.

## ADs that may apply (OpenAirDocs): 0 in force

### Matched by airframe (Hiller OH-23G)

None in force.

## Information bulletins (advisory)

None matched.

## NTSB investigations

None matched to N99579.

## NTSB investigations on N99579 not matched to an aircraft (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.

## FAA accident and incident reports (1)

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.

- [Accident 20110623012719A](https://openairdocs.org/incident/20110623012719A), Jun 23, 2011: Hiller UH-12E (N99579), Hanford, CA, Substantial damage. 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…

## Service difficulty reports

None filed for this aircraft. Matched to this aircraft by N-number and event date, checked against the reported serial number, make and model.

## STCs that may be installed (OpenAirDocs)

None matched to this aircraft's models.

## Related

- Other Hiller OH-23G aircraft: https://openairdocs.org/model/hiller-oh-23g/aircraft.md

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