# NTSB SEA85FA162: Beech B36TC, N948ST, Idaho City, ID, July 12, 1985

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: July 12, 1985, 10:27 local (16:27 UTC)
- Place: Idaho City, ID
- Coordinates: 43.870834, -115.639038 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.8708&lon=-115.6390&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 40053
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA85FA162
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/40053/pdf
- Page: https://openairdocs.org/ntsb/SEA85FA162

## Sequence of events

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

- In flight encounter with weather, cruise - normal
  - preflight briefing service - not used, pilot in command (contributing factor)
  - weather evaluation - misjudged, pilot in command (cause)
- Loss of control - in flight, climb - to cruise
  - weather condition - turbulence in clouds (cause)
- In flight collision with terrain/water, descent - uncontrolled
  - spiral - uncontrolled, pilot in command (cause)
  - became lost/disoriented, pilot in command (contributing factor)
  - panic, pilot in command (contributing factor)

## Analysis

THE PLT FAILED TO OBTAIN A PREFLT WX BRIEFING PRIOR TO DEPARTING BOTH BUTTE, MT, AND SALMON, ID. EN ROUTE AT FL180 HE ENTERED INSTRUMENT AND ICING CONDITIONS WHICH HE ATTEMPTED TO AVOID BY CLIMBING TO FL200. DURING THE CLIMB, THE PLT REPORTED ENCOUNTERING SEVERE TURBULENCE ASSOCIATED WITH DEVELOPING CUMULONIMBUS ACTIVITY. CONTROL OF THE ACFT WAS LOST AND THE ACFT DESCENDED TO GROUND IMPACT.

## Aircraft

- Registration: N948ST (not matched to a registry record)
- Reported make and model: BEECH B36TC
- Category: Airplane
- Serial number: EA279
- Engines: CONTINENTAL TSIO-520-UB 300 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Personal, Part 91
- Operator: Michael E. Quesnoy
- Registered owner: Visalia Electric Motor Shop
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, October 16, 1984
- Departed: SMN, SALMON, ID
- Destination: VIS, VISALIA, CA
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 350 total, 2 in the last 24 hours

## Weather

- Conditions: Day
- Wind: 20° at 7 knots
- Visibility: 10 statute miles
- Lowest ceiling: 14,000 ft broken
- Temperature: 75 °F, dew point 55 °F
- Altimeter: 30.00 inHg
- Observed at: BOI, 30 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 19850712030889A](https://openairdocs.org/incident/19850712030889A), Jul 12, 1985: Beech B36TC, Idaho City, ID, Destroyed, 1 fatal. Attempted to climb on top of thunderstorms. Uncontrolled descent and ground impact after encountering turbulence.

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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