# NTSB SEA89LA061: Mitsubishi MU-2B-35J, N54US, Spokane, WA, February 17, 1989

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: February 17, 1989, 07:13 local (15:13 UTC)
- Place: Spokane, WA
- Location: 47.6190° N, 117.5352° W: Placed by OpenAirDocs at SPOKANE INTL (GEG), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=47.6190&lon=-117.5352&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report January 22, 1991
- Report: Approved by Office Director
- NTSB case key (mKey): 40990
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA89LA061
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/40990/pdf
- Page: https://openairdocs.org/ntsb/SEA89LA061

## Probable cause

THE FAILURE OF THE PILOT TO MAINTAIN DIRECTIONAL CONTROL AND RUNWAY ALIGNMENT DURING THE LANDING ROLL. FACTORS RELATED TO THE ACCIDENT WERE: LIGHT CONDITIONS AT DAWN, SNOW AND ICE ON THE RUNWAY, AND THE RUNWAY LIGHTS.

## Sequence of events

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

- On ground/water collision with object, landing - roll
  - light condition - dawn (contributing factor)
  - airport facilities,runway/landing area condition - snow covered (contributing factor)
  - airport facilities,runway/landing area condition - icy (contributing factor)
  - directional control - not maintained, pilot in command (cause)
  - object - runway light (contributing factor)
  - proper alignment - not maintained, pilot in command (cause)

## Analysis

WHILE LANDING AT DAWN WITH SNOW & ICE ON THE RWY, THE ACFT DRIFTED LEFT INTO RUNWAY LIGHTS, WHICH WERE BURIED IN A SNOW BERM FROM PREVIOUS PLOWING. THE PLT SAID THERE WAS 16 INCHES OF SNOW ON THE GND & UP TO 2 INCHES ON THE RWY. HE SAID HE THOUGHT HE HAD LANDED ON THE CENTERLINE, LOST CONTROL IN A SNOWDRIFT, THEN THE ACFT DRIFTED INTO SNOW ADJACENT TO THE RWY.

## Aircraft

- Registration: N54US (not matched to a registry record)
- Reported make and model: MITSUBISHI MU-2B-35J
- Category: Airplane
- Serial number: 590
- Airframe hours: 4076
- Engines: GARRETT TPE-331-6 715 horsepower turbo prop
- Damage: Substantial damage
- Flight: Part 135
- Registered owner: Richardson Aviation
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, January 12, 1989, 30 hours before
- Departed: BFI, SEATTLE, WA
- Flight plan: IFR
- Airport: GEG, Spokane Int'L, runway 3, 9,000 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 44; flight instructor, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 6,471 total, 520 in this make and model, 5,587 as pilot in command, 240 in the last 90 days, 92 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Instrument (IMC), Dawn
- Wind: 40° at 11 knots
- Visibility: 2 statute miles
- Lowest ceiling: 900 ft
- Temperature: 16 °F, dew point 12 °F
- Altimeter: 30.00 inHg
- Observed at: GEG

## 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 19890217066799A](https://openairdocs.org/incident/19890217066799A), Feb 17, 1989: Mtsbsi MU2B35, Spokane, WA, Substantial damage. Landed off centerline due snow on runway. Drifted off. Lost control in snow drift. Struck snow covered runway light

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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