Cessna C-172 accident near Colstrip, Montana, February 3, 1991
On February 3, 1991 at about 2:45 am local time, a Cessna C-172, registered N8531B, was destroyed in an accident near Colstrip, Montana (Colstrip airport). It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
THE PILOT'S FAILURE TO MAINTAIN ADEQUATE TERRAIN CLEARANCE. FACTORS RELATING TO THE ACCIDENT WERE THE PILOT'S LACK OF TOTAL NIGHT FLIGHT EXPERIENCE, HIS LACK OF RECENT NIGHT FLIGHT EXPERIENCE, THE DARK NIGHT LIGHT CONDITIONS, AND THE MOUNTAINOUS/HILLY TERRAIN IN THE AREA.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 3, 1991 · about 2:45 am local time
- Place
- Colstrip, Montana · Colstrip · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna C-172
- Registration
- N8531B · no longer on the register · serial 17236231
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
THE ACFT IMPACTED A RIDGELINE ON DOWNWIND IN THE TRAFFIC PATTERN WHILE THE PILOT WAS ON A NIGHT CURRENCY TRAINING FLIGHT AT A RECENTLY OPENED LIGHTED AIRPORT. THE PILOT HAD 4 HOURS TOTAL NIGHT FLIGHT TIME, WITH .8 HOURS PIC, ALL FLOWN DURING INITIAL PILOT TRAINING IN 1984. HE HAD NO RECORDED NIGHT FLIGHT TIME SINCE. HE WAS NOT INSTRUMENT RATED AND HAD NO INSTRUMENT FLIGHT TIME. THE AIRPORT IS LOCATED IN AN UNPOPULATED MOUNTAINOUS AREA WITH VERY LITTLE ARTIFICIAL LIGHT. THERE WAS NO NATURAL ILLUMINATION AT THE TIME OF THE ACCIDENT.
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: private
- Ratings: single-engine land
- Flight time: 279 hours in all; 153 in this make and model; 7 in the last 90 days; 2 in the last 30 days; 220 as pilot in command
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: unk
The aircraft
- Last inspection: inspection type not recorded; 0 hours since
- Maximum gross weight: 2,200 lb
- Seats: 4
- Landing gear: fixed
- Engine: Continental O-300-D (piston); 0 hours total
The flight
- Departed from: M46 Colstrip MT at 2:45 am
- Flight plan: none
- Runway 24, 5,100 ft by 75 ft
Weather at the time
- Light: night, dark
- Wind: from 180° at 7 knots
- Visibility: 10 statute miles
- Sky: scat at 25,000 ft
- Temperature: 36°F (2°C), dew point 27°F (-3°C)
- Observation at 4:48 am from MLS, 49 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.