# NTSB SEA92FA154: Beech 58, N23LB, Pierce, ID, July 8, 1992

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: July 8, 1992, 09:33 local (16:33 UTC)
- Place: Pierce, ID
- Coordinates: 46.559947, -115.809288 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=46.5599&lon=-115.8093&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 2 fatal
- Status: Completed, report September 14, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 41587
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA92FA154
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41587/pdf
- Page: https://openairdocs.org/ntsb/SEA92FA154

## Probable cause

INFLIGHT LOSS OF CONTROL WHEN AIRCRAFT CONTROL WAS NOT MAINTAINED. FACTORS TO THE ACCIDENT WERE: FLIGHT INTO KNOWN ADVERSE WEATHER AND THUNDERSTORM ACTIVITY.

## Sequence of events

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

- In flight encounter with weather, maneuvering
  - weather condition - thunderstorm (contributing factor)
  - flight into known adverse weather - attempted, pilot in command (contributing factor)
- Loss of control - in flight, maneuvering
  - aircraft control - not maintained, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - mountainous/hilly

## Analysis

PRIOR TO TAKEOFF, THE PILOT OBTAINED A WEATHER BRIEFING AND WAS INFORMED OF MOUNTAIN OBSCUREMENT, RAIN SHOWERS, AND THUNDERSTORM ACTIVITY IN THE AREA OF THE FLIGHT PATH. THE PILOT HAD FILED THE ROUTE OF FLIGHT DIRECT FROM BOISE, ID, TO MCCALL, ID, TO THOMPSON FALLS, MT, TO KALISPELL, MT. THE ACCIDENT SITE WAS LOCATED APPROXIMATELY 45 MILES EAST OF THE DIRECT LINE OF FLIGHT PATH IN MOUNTAINOUS TERRAIN. RADAR DATA IDENTIFIES THE FLIGHT AS MANEUVERING ON VARIOUS HEADINGS BEFORE THE FLIGHT DROPPED FROM RADAR CONTACT. THE WRECKAGE WAS FOUND CONFINED TO A DEEP CRATER WITH THE NOSE OF THE AIRPLANE AT THE CRATER'S DEEPEST POINT. IT WAS ESTIMATED THAT THE AIRPLANE COLLIDED WITH THE TERRAIN IN AN APPROXIMATE 70 DEGREE NOSE DOWN ATTITUDE. THERE WAS NO EVIDENCE FOUND TO INDICATE A MECHANICAL FAILURE OR MALFUNCTION.

## Aircraft

- Registration: [N23LB](https://openairdocs.org/deregistered/N23LB-1993-02-24), registration cancelled 1993-02-24, S/N TH837 (OpenAirDocs)
- Reported make and model: BEECH 58
- Registry model: [Beech 58](https://openairdocs.org/model/beech-58) (registry code 1152740) (OpenAirDocs)
- Category: Airplane
- Serial number: TH-837
- Airframe hours: 2190
- Engines: CONTINENTAL IO-520-C 285 horsepower reciprocating
- Damage: Destroyed
- Flight: Personal, Part 91
- Operator: Sinclair, Richard C.
- Registered owner: Sinclair, Richard C.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, July 1, 1992, 6 hours before
- Departed: BOI, BOISE, ID
- Destination: FCA, KALISPELL, MT
- Flight plan: VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 62; private; airplane ratings: single-engine land, multi-engine land; medical: class 3, valid medical--w/ waivers/lim; flight hours: 1,416 total, 123 in this make and model, 20 in the last 90 days, 7 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Day
- Wind: 270° at 10 knots
- Temperature: 70 °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 19920708033049A](https://openairdocs.org/incident/19920708033049A), Jul 8, 1992: Beech 58, Pierce, ID, Destroyed, 2 fatal. Wreckage indicates near vertical spiral dive. Thunderstorms,rain and fog in area.

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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