# NTSB SEA85LA097: Hiller 12E, N99GM, Myrtle Point, OR, April 26, 1985

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: April 26, 1985, 09:00 local (17:00 UTC)
- Place: Myrtle Point, OR
- Coordinates: 43.059165, -124.030242 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.0592&lon=-124.0302&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): 40146
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA85LA097
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/40146/pdf
- Page: https://openairdocs.org/ntsb/SEA85LA097

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, cruise - normal
  - compressor assembly,impeller - fatigue (cause)
  - compressor assembly,impeller - failure,total (cause)
- Forced landing, descent - emergency
  - autorotation - performed, pilot in command (contributing factor)
- In flight collision with terrain/water, landing - flare/touchdown
  - terrain condition - uphill (contributing factor)
  - terrain condition - high terrain (contributing factor)
  - terrain condition - tree(s) (contributing factor)

## Analysis

DURING A CFR 137 FLIGHT A TOTAL LOSS OF POWER OCCURRED WITH AN AUDIBLE SCREECH COMING FORM THE ENGINE AREA. AUTOROTATION WAS MADE AND THE ACFT WAS LANDED INTO A HEVILY TREED AREA WITH STEEP TERRAIN. DURING ENGINE TEAR DOWN A FRACTURED IMPELLER WAS FOUND. METALLURGICAL ANALYSIS REVEALED THAT THE FRACTURED IMPELLER WAS DUE TO PROGRESSION OF A PRE-EXISTING FATIGUE CRACK IN THE IMPELLER.

## Aircraft

- Registration: N99GM (not matched to a registry record)
- Reported make and model: HILLER 12E
- Category: Helicopter
- Serial number: 1498
- Airframe hours: 4053
- Engines: ALLISON 250-C20B 305 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Reforestation Services Inc.
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: 100 hour, September 28, 1984, 57 hours before
- Destination: NONE, MYRTLE POINT, OR
- Airport: None

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; commercial, flight instructor; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 12,402 total, 7,272 in this make and model, 12,250 as pilot in command, 96 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 30 statute miles
- Lowest ceiling: none
- Temperature: 50 °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 19850426015699A](https://openairdocs.org/incident/19850426015699A), Apr 26, 1985: Hiller UH12E, Myrtle Point, OR, Substantial damage. Total power loss followed loud screech. Landed in tall trees on sloping terrain. Impeller failure fatigue crack.

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.