Swearingen SA226TC incident near Billings, Montana, December 20, 1986
On December 20, 1986 at about 4:10 am local time, a Swearingen SA226TC, registered N124AV, suffered minor damage in an incident near Billings, Montana (Billings Logan Int'L. airport). It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). No one was hurt; 13 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this incident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- December 20, 1986 · about 4:10 am local time
- Place
- Billings, Montana · Billings Logan Int'L. · map
- Type
- Incident
- Injuries
- No one was hurt; 13 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Swearingen SA226TC · all SA226TCs on the register
- Registration
- N124AV · no longer on the register · serial TC 364
- Damage
- Minor damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
N124AV WAS OPERATING AS BIG SKY AIRLINES FLT 3857, SCHEDULED SERVICE FROM HELENA TO BILLINGS. THE FLT PROCEEDED UNEVENTFULLY UNTIL THE APCH INTO BILLINGS. THE FLT CREW STATED AFTER THE INCIDENT THAT WHEN THE LANDING GEAR WAS EXTENDED, THE LEFT MAIN GEAR LIGHTS DID NOT ILLUMINATE, VERIFYING THE 'DOWN AND LOCKED POSITION..' AFTER NUMEROUS ATTEMPTS TO ILLUMINATE THE LIGHTS AND CONFIRM THE POSITION OF THE LANDING GEAR, THE CREW EXECUTED AN INTENTIONAL GEAR UP LANDING. POST INCIDENT INSPECTION OF THE LANDING GEAR SYSTEM REVEALED IT WAS CAPABLE OF NORMAL OPERATION. THE MALFUNCTIONING COCKPIT INDICATOR LIGHT WAS TRACED BACK TO AN INOPERATIVE OUTBOARD DOWNLOCK MICROSWITCH.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: airline transport pilot, commercial pilot
- Ratings: multi-engine land; multi-engine sea; single-engine land; single-engine sea; instrument: airplane; rotorcraft: helicopter
- Flight time: 7,000 hours in all
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 11,273 hours
- Last inspection: continuous airworthiness programme, December 19, 1986; 36 hours since
- Maximum gross weight: 12,500 lb
- Seats: 15
- Landing gear: retractable
- Engine: Garrett TPE331-3U303G (turboprop); 0 hours total
- Operator: Big Sky Airlines
The flight
- Departed from: HLN Helena MT at 2:48 am
- Destination: BIL Billings MT
- Flight plan: IFR
- Runway 27R, 10,500 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: night, dark
- Wind: from 230° at 11 knots
- Visibility: 20 statute miles
- Sky: overcast at 20,000 ft; scat at 14,000 ft
- Temperature: 30°F (-1°C), dew point 10°F (-12°C)
- Altimeter: 30.00 inHg
- Observation at 4:17 am from BIL
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 2 | |||
| Passengers | 11 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Other NTSB records under N124AV the same tail number, which may have belonged to a different aircraft at the time
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.