# NTSB SEA86LA235: Cessna 182D, N8778X, Stibnite, ID, August 30, 1986

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Limited investigation · Final report
- Date: August 30, 1986, 11:50 local (17:50 UTC)
- Place: Stibnite, ID
- Coordinates: 45.019271, -115.520668 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=45.0193&lon=-115.5207&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal, 3 serious
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 40493
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA86LA235
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/40493/pdf
- Page: https://openairdocs.org/ntsb/SEA86LA235

## Sequence of events

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

- In flight collision with object, maneuvering - turn to reverse direction
  - planning/decision - improper, pilot in command (cause)
  - terrain condition - mountainous/hilly (contributing factor)
  - terrain condition - rising (contributing factor)
  - weather condition - unfavorable wind (contributing factor)
  - weather condition - downdraft (contributing factor)
  - weather condition - high density altitude (contributing factor)
  - object - tree(s) (contributing factor)
  - proper climb rate - not possible

## Analysis

AFTER TAKING OFF IN MOUNTAINOUS TERRAIN, THE PILOT PREMATURELY TURNED ON COURSE TO A NORTHERLY HEADING, INTENDING TO CROSS OVER A RIDGE LINE. SHORTLY AFTER THE TURN, AND WHILE FLYING UP A DRAINAGE AREA TOWARDS RISING TERRAIN, HE ENCOUNTERED A DOWNDRAFT CONDITION WHICH REDUCED THE AIRCRAFT'S CLIMB PERFORMANCE. ITS CLIMB PERFORMANCE HAD ALREADY BEEN AGGRAVATED BY HIGHER THAN USUAL DENSITY ALTITUDE CONDITIONS. SUBSEQUENTLY, THE AIRCRAFT COLLIDED WITH TREES WHILE THE PILOT WAS ATTEMPTING TO REVERSE COURSE.

## Aircraft

- Registration: [N8778X](https://openairdocs.org/deregistered/N8778X-2013-05-15), registration cancelled 2013-05-15, S/N 18253178, built 1961 (OpenAirDocs)
- Reported make and model: CESSNA 182D
- Registry model: [Cessna 182D](https://openairdocs.org/model/cessna-182d) (registry code 2072710) (OpenAirDocs)
- Registry engine: [Continental O-470 series](https://openairdocs.org/engine/continental-o-470-series) (registry code 17026, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 18253178
- Airframe hours: 3002
- Engines: CONTINENTAL O-470-L 230 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Alan T. Bermensolo
- Registered owner: K & C Flying
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, July 3, 1986, 11 hours before
- Departed: S81
- Destination: U79, CHAMBERLAIN BAS, ID
- Airport: Indian Creek (Usfs), runway 4, 5,000 × 100 ft, gravel

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 32; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 380 total, 199 in this make and model, 331 as pilot in command, 36 in the last 90 days, 3 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 360° at 7 knots
- Visibility: 25 statute miles
- Lowest ceiling: 10,000 ft broken
- Temperature: 64 °F, dew point 55 °F
- Observed at: SMN, 55 nm away

## 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 19860830043199A](https://openairdocs.org/incident/19860830043199A), Aug 30, 1986: Cessna STC182, Stibnite, ID, Destroyed, 2 fatal. The aircraft stalled and impacted a ridge in mountainous terrain. Downdrafts and density altitude are factors.

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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