# NTSB SEA93LA027: Swearingen SA-226TC, N139PA, Billings, MT, November 21, 1992

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: November 21, 1992, 01:29 local (08:29 UTC)
- Place: Billings, MT
- Location: 45.8078° N, 108.5435° W: Placed by OpenAirDocs at BILLINGS LOGAN INTL (BIL), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=45.8078&lon=-108.5435&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report May 26, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 42964
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA93LA027
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/42964/pdf
- Page: https://openairdocs.org/ntsb/SEA93LA027

## Probable cause

FAILURE OF A GEAR DOOR ROLLER, WHICH NECESSITATED A GEAR UP LANDING. FACTORS INCLUDE INADEQUATE LUBRICATION.

## Analysis

AFTER GETTING A GEAR UNSAFE LIGHT ON THE RIGHT MAIN LANDING GEAR WHEN THE PILOTS ATTEMPTED TO EXTEND THE LANDING GEAR, THEY ELECTED TO FLY BACK TO THEIR MAINTENANCE FACILITY.  AFTER REPEATED ATTEMPTS TO RECTIFY THE PROBLEM, THEY SUCCESSFULLY ACCOMPLISHED A PRECAUTIONARY GEAR UP LANDING. INVESTIGATION REVEALED THAT THE RIGHT MAIN LANDING GEAR DOOR ROLLER WAS FRACTURED AND PREVENTED THE RIGHT MAIN GEAR FROM EXTENDING.

## Sequence of events

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

- Gear not extended, landing
  - landing gear,normal retraction/extension assembly - failure,partial (cause)
  - maintenance,lubrication - inadequate, other maintenance personnel (contributing factor)

## Aircraft

- Registration: [N139PA](https://openairdocs.org/deregistered/N139PA-1996-05-03), registration cancelled 1996-05-03, S/N TC296 (OpenAirDocs)
- Reported make and model: SWEARINGEN SA-226TC
- Registry model: [Swearingen SA226TC](https://openairdocs.org/model/swearingen-sa226tc) (registry code 8780404) (OpenAirDocs)
- Category: Airplane
- Serial number: TC-296
- Airframe hours: 17392
- Engines: GARRETT TPE-331-10UA 840 horsepower turbo prop
- Damage: Substantial damage
- Flight: Part 135
- Operator: Big Sky Transportation Co, doing business as Big Sky Airlines
- Registered owner: First Security Bank Utah, N.A.
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, November 18, 1992, 13 hours before
- Departed: SDY, SIDNEY, MT
- Destination: ISN, WILLISTON, ND
- Flight plan: IFR
- Airport: BIL, Billings Logan Internat., runway 27, 10,528 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 40; 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: 8,851 total, 2,821 in this make and model, 6,738 as pilot in command, 165 in the last 90 days, 50 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: 180° at 6 knots
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: 27 °F, dew point 19 °F
- Altimeter: 30.00 inHg
- Observed at: BIL, 1 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 19921121053389A](https://openairdocs.org/incident/19921121053389A), Nov 21, 1992: Swrngn SA226TC, Billings, MT, Substantial damage. Unable extend right main gear. Landed gear up. Gear door roller bearing had fractured.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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