# NTSB SEA89FA113: Piper PA-23-250, N6471Y, Stanley, ID, June 20, 1989

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: June 20, 1989, 13:15 local (19:15 UTC)
- Place: Stanley, ID
- Coordinates: 44.259994, -114.969581 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=44.2600&lon=-114.9696&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 3 fatal
- Status: Completed, report September 30, 1991
- Report: Approved by Office Director
- NTSB case key (mKey): 40923
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA89FA113
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/40923/pdf
- Page: https://openairdocs.org/ntsb/SEA89FA113

## Probable cause

PILOT CONTINUED VFR FLIGHT INTO IMC CONDITIONS IN MOUNTAINOUS TERRAIN. FACTORS WERE SNOW SQUALLS AND OBSCURED MOUNTAINOUS TERRAIN IN THE AREA.

## Sequence of events

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

- In flight encounter with weather, cruise - normal
  - weather condition - snow (contributing factor)
  - weather condition - obscuration (contributing factor)
  - vfr flight into imc - continued, pilot in command (cause)
- In flight collision with terrain/water, maneuvering - turn to reverse direction
  - terrain condition - mountainous/hilly (contributing factor)

## Analysis

AIRCRAFT WAS OBSERVED FLYING ABOUT 800 FT AGL ALONG A RIVER IN A MOUNTAIN VALLEY WITH STEEP HIGH TERRAIN ON BOTH SIDES. SUBSEQUENTLY, IT FLEW INTO SNOW SQUALL, IMPACTED TREES 6000 FT MSL ON HILLSIDE 1/4 MILE FROM THE RIVER. PLT BRIEFED ON MOUNTAIN OBSCURATIONS, ADVISED TO UPDATE WEATHER LATER IN FLIGHT.

## Aircraft

- Registration: [N6471Y](https://openairdocs.org/deregistered/N6471Y-1990-08-10), registration cancelled 1990-08-10, S/N 273766 (OpenAirDocs)
- Reported make and model: PIPER PA-23-250
- Registry model: [Piper PA-23-250](https://openairdocs.org/model/piper-pa-23-250) (registry code 7102308) (OpenAirDocs)
- Category: Airplane
- Serial number: 27-3766
- Airframe hours: 4461
- Engines: LYCOMING IO-540 250 horsepower reciprocating
- Damage: Destroyed
- Fire: On-Ground
- Flight: Personal, Part 91
- Registered owner: Gregory R. Rost
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, December 22, 1988
- Departed: EAT, WENATCHEE, WA
- Destination: U15, CHALLIS, ID
- Flight plan: VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; commercial, flight instructor; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; toxicology performed; flight hours: 3,400 total, 200 in this make and model, 3,100 as pilot in command

## Weather

- Conditions: Instrument (IMC), Day
- Wind: 330° at 25 knots, gusting 32
- Visibility: 50 statute miles
- Lowest ceiling: 3,000 ft overcast
- Temperature: 45 °F, dew point 28 °F
- Altimeter: 30.00 inHg
- Observed at: U15, 24 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 19890620016249A](https://openairdocs.org/incident/19890620016249A), Jun 20, 1989: Piper PA23250, Stanley, ID, Destroyed, 3 fatal. Struck trees on cloud obscured mountainside while following river at low altitude. A snowstorm in area of crash.

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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