# NTSB SEA87FA106: Hiller UH-12E, N28875, Shelton, WA, May 28, 1987

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: May 28, 1987, 16:30 local (23:30 UTC)
- Place: Shelton, WA
- Coordinates: 47.230342, -123.199409 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.2303&lon=-123.1994&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report July 5, 1988
- Report: Approved by Office Director
- NTSB case key (mKey): 40521
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA87FA106
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/40521/pdf
- Page: https://openairdocs.org/ntsb/SEA87FA106

## Sequence of events

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

- Abrupt maneuver, cruise
  - weather condition - windshear (contributing factor)
  - rotorcraft flight controls - excessive, pilot in command (cause)
  - lack of total experience in type of aircraft, pilot in command (contributing factor)
  - weather condition - turbulence (contributing factor)
  - rotor drive system,main rotor mast(drive shaft) - failure,total (cause)
  - rotor system - separation (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE PILOT WAS PROPERLY CERTIFICATED FOR THE FLIGHT; HOWEVER, DUE TO OPERATOR INSURANCE RESTRICTIONS, ALL PRIOR COMMERCIAL FLIGHTS HAD REQUIRED THE OWNER/OPERATOR TO ACCOMPANY THIS PILOT, THEREFORE THIS WAS THE PILOT'S FIRST COMMERCIAL FLIGHT AS SOLE PILOT. RETURNING TO BASE AFTER A ROUND-TRIP PASSENGER FLIGHT, HAVING DISEMBARKED PASSENGERS, THE AIRCRAFT WAS OBSERVED PROCEEDING AT HIGH FORWARD SPEED IN STRONG BUT INTERMITTENT WIND CONDITIONS. ALSO, PASSENGERS REMARKED ABOUT TURBULENCE ALONG THIS SAME ROUTE OF FLIGHT EARLIER. INVESTIGATION REVEALED THE MAIN ROTOR SEPARATED IN FLIGHT DUE TO MAST BUMPING, A PHENOMENON ASSOCIATED WITH TEETERING ROTOR SYSTEMS, INDUCED BY EXCEEDING THE NORMAL FLIGHT ENVELOPE FOR THE AIRCRAFT.

## Aircraft

- Registration: [N28875](https://openairdocs.org/deregistered/N28875-1998-04-17), registration cancelled 1998-04-17, S/N 2143 (OpenAirDocs)
- Reported make and model: HILLER UH-12E
- Registry model: [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e) (registry code 4360122) (OpenAirDocs)
- Category: Helicopter
- Serial number: 2143
- Airframe hours: 12094
- Engines: ALLISON 250-C20 400 horsepower turbo shaft
- Damage: Destroyed
- Flight: Positioning, Part 91
- Operator: Olympic Air, Inc.
- Registered owner: Olympic Air, Inc
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, May 25, 1987, 11 hours before
- Departed: S42, SILVERDALE, WA
- Destination: SHN, SHELTON, WA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 26; commercial, private; airplane ratings: single-engine land; medical: class 1, valid medical--no waivers/lim.; seat: left; toxicology performed; flight hours: 930 total, 123 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 220° at 25 knots, gusting 35
- Visibility: 25 statute miles
- Lowest ceiling: none
- Temperature: 61 °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 19870528079719A](https://openairdocs.org/incident/19870528079719A), May 28, 1987: Hiller UH12E, Shelton, WA, Destroyed, 1 fatal. Lost control of aircraft. Impacted ground in vertical position. Main rotor shows overload failure. Severe turbulence

## Other investigations on N28875 (2)

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 SEA81DYE11](https://openairdocs.org/ntsb/SEA81DYE11), Jan 7, 1981: Hiller Acft UH-12E (N28875), Beaver, WA, substantial damage
- [NTSB SEA74DYE32](https://openairdocs.org/ntsb/SEA74DYE32), Dec 28, 1973: Hiller UH-12E (N28875), Queets, WA, destroyed

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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