Cessna 421C accident near Butte, Montana, November 6, 1986
On November 6, 1986 at about 11:36 am local time, a Cessna 421C, registered N421AR, was destroyed in an accident near Butte, Montana. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). 1 person was killed. The weather was instrument conditions (cloud, fog or low visibility).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. 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
- November 6, 1986 · about 11:36 am local time
- Place
- Butte, Montana
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft
- Cessna 421C · all 421Cs on the register
- Registration
- N421AR · registry record · serial 421C0254
- Damage
- Destroyed
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
PLT WAS ATTEMPTING THE VOR-B INSTRUMENT APCH TO BUTTE, MT ARPT. PLT REPORTED OVER THE COPPERTOWN VORTAC INBOUND ON THE ARPT. THE PROCEDURE TURN INBOUND COURSE TO THE VORTAC IS 124 DEGREES. THE INBOUND COURSE TO THE ARPT IS 094 DEGREES. THE ACFT WRECKAGE WAS FOUND ON THE 124 DEGREE RADIAL 5 MILES SW OF THE ARPT. THE WIND WAS REPORTED TO BE 340 DEGREES AT 9 KTS. THE VOR-B APCH TERMINATES AT RWY 11. RWY 33 IS 9000 FT LONG AND EQUIPPED WITH MIRL'S AND REIL'S.
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
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 4,000 hours in all
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 2,890 hours
- Last inspection: 100-hour inspection, October 20, 1986; 50 hours since
- Maximum gross weight: 7,450 lb
- Seats: 1
- Landing gear: retractable
- Engine: Continental GTSIO-520-L (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: HLN Helena MT at 11:14 am
- Flight plan: IFR
- Runway 0
Weather at the time
- Light: night, dark
- Wind: from 340° at 9 knots
- Visibility: 2 statute miles
- Sky: clear
- Temperature: 28°F (-2°C), dew point 27°F (-3°C)
- Altimeter: 29.00 inHg
- Observation at 10:51 am from BTM, 5 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
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.
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.