# NTSB SEA82DA137: Hughes 369D, N10966, Shelton, WA, August 7, 1982

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: August 7, 1982, 14:03 local (21:03 UTC)
- Place: Shelton, WA
- Coordinates: 47.229679, -123.199089 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=47.2297&lon=-123.1991&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed, report August 7, 1983
- Report: Approved by Office Director
- NTSB case key (mKey): 72609
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA82DA137
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/72609/pdf
- Page: https://openairdocs.org/ntsb/SEA82DA137

## Analysis

DURING A SIGHT SEEING FLIGHT THE PILOT SMELLED A BURNING ODOR AND PREPARED TO MAKE A PRECAUTIONARY OFF-AIRPORT LANDING. SHORTLY THEREAFTER, ENGINE RPM DECAYED AND AN AUTOROTATIVE LANDING WAS EFFECTED ON A DIRT ROAD. ON TOUCHDOWN, THE MAIN ROTOR BLADES FLEXED DOWNWARD, STRIKING THE TAIL BOOM AND SEPARATING IT FROM THE FUSELAGE. THE INVESTIGATION REVEALED THETURBINE-TO-COMPRESSOR COUPLING WAS BOUND TO THE POWER TURBINE SHAFT WHICH SLEEVES IT. THERE WAS EVIDENCE OF THERMAL AND MECHANICAL DISTRESS TO THE COMPONENTS, CAUSED BY OVER-HEATING AND COKING OF THE OIL.

## 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
  - lubricating system - blocked(total) (cause)
- Forced landing, landing - flare/touchdown
  - autorotation - performed, pilot in command (contributing factor)
- Hard landing, landing - flare/touchdown
  - rotor system,main rotor blade - engaged
  - rotor system,tail rotor hub - separation

## Aircraft

- Registration: [N10966](https://openairdocs.org/deregistered/N10966-2003-07-29), registration cancelled 2003-07-29, S/N 1000818D, built 1980 (OpenAirDocs)
- Reported make and model: HUGHES 369D
- Registry model: [Hughes Helicopters HUGHES 369D](https://openairdocs.org/model/hughes-helicopters-hughes-369d) (registry code 4470706) (OpenAirDocs)
- Registry engine: [Allison 250 SER 250HP](https://openairdocs.org/engine/allison-250-ser-250hp) (registry code 03002, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 1000818D
- Airframe hours: 1259
- Engines: ALLISON 25O-C20B 420 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Part 91
- Operator: Olympic Air, Inc.
- Registered owner: Olympic Air, Inc.
- Departed: SHN, SHELTON, WA
- Destination: SHN, SHELTON, WA
- Airport: SHN, Sanderson Field

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 28; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; flight hours: 1,665 total, 107 in this make and model, 1,458 as pilot in command, 230 in the last 90 days, 62 in the last 30 days, 7 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 20 statute miles
- Temperature: 194 °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 19820807053009A](https://openairdocs.org/incident/19820807053009A), Aug 7, 1982: Hughes 369D, Shelton, WA, Substantial damage. Smelled smoke and lost power. Tailboom cut off on hard landing. Engine turbine section locked up from oil coking.

## Other investigations on N10966 (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 SEA83LA205](https://openairdocs.org/ntsb/SEA83LA205), Sep 26, 1983: Hughes 369B (N10966), Cougar, 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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