# NTSB LAX86LA277: Hiller UH-12C, N26186, Garberville, CA, July 2, 1986

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 2, 1986, 15:30 local (22:30 UTC)
- Place: Garberville, CA
- Location: 40.1003° N, 123.7943° W: Placed by OpenAirDocs: center of Garberville, CA, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=40.1003&lon=-123.7943&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 25203
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX86LA277
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/25203/pdf
- Page: https://openairdocs.org/ntsb/LAX86LA277

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of engine power, cruise - normal
  - rotor drive system,clutch assembly - failure,partial (cause)
  - engine assembly,crankcase - leak (contributing factor)
  - fluid,oil - leak (contributing factor)
  - operation with known deficiencies in equipment - attempted, pilot in command (cause)
  - lack of familiarity with aircraft, pilot in command (contributing factor)
- Forced landing, descent - emergency
- In flight collision with terrain/water, landing - flare/touchdown
  - terrain condition - rough/uneven (contributing factor)

## Analysis

THE STUDENT PLT HAD JUST TAKEN OFF ON A TRAINING X-COUNTRY FLT WHEN THE MAIN ROTOR TACHOMETER NEEDLE DECREASED BELOW THE ENGINE TACHOMETER NEEDLE. HE TURNED THE HELICOPTER TO RETURN TO THE ARPT BUT WAS UNABLE TO MAINTAIN ALTITUDE AND LANDED HARD IN ROUGH TERRAIN. AFTER THE ACCIDENT THE STUDENT PLT STATED THAT HE HAD OBSERVED OIL LEAKING IN THE VICINITY OF THE CENTRIFUGAL, DRY CLUTCH DURING THIS AND PREVIOUS PREFIGHT INSPECTIONS.

## Aircraft

- Registration: [N26186](https://openairdocs.org/deregistered/N26186-2019-01-14), registration cancelled 2019-01-14, S/N AN-002, built 1957 (OpenAirDocs)
- Reported make and model: HILLER UH-12C
- Registry model: [Hiller-Nunes UH-12C](https://openairdocs.org/model/hiller-nunes-uh-12c) (registry code 4360113) (OpenAirDocs)
- Registry engine: [Franklin 6A&6V335 series](https://openairdocs.org/engine/franklin-6a-6v335-series) (registry code 27020, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: AN002
- Airframe hours: 1799
- Engines: FRANKLIN VO-335-5D 210 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Dane A. Peterson
- Registered owner: Petersen, Dane A.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, March 27, 1986, 48 hours before
- Departed: 016, GARBERVILLE, CA
- Destination: 028
- Flight plan: VFR
- Airport: Garberville

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 37; student; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 39 total, 39 in this make and model, 12 as pilot in command, 39 in the last 90 days, 19 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 330° at 5 knots, gusting 5
- Visibility: 25 statute miles
- Lowest ceiling: none
- Temperature: 84 °F

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19860702029759A](https://openairdocs.org/incident/19860702029759A), Jul 2, 1986: Hiller UH12C, Garberville, CA, Substantial damage. The helicopter landed when rotor RPM decayed. Main rotor centrifugal clutch was oil soaked due to a leaking seal.

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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