Avia Stroitel AC-5m accident near Bozeman, Montana, March 4, 2001
On March 4, 2001 at about 8:00 pm local time, a Avia Stroitel AC-5m (glider), an amateur-built aircraft,, registered N1635M, was substantially damaged in an accident near Bozeman, Montana (Gallatin Field). It was a personal flight under general aviation rules (Part 91). 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
the pilot's improper remedial action upon experiencing the unexpected opening of the aircraft's canopy during the initial part of the takeoff climb. Factors include his attention being diverted to the open canopy, his failure to use a checklist to ensure he did not miss any critical pre-takeoff actions, his failure to lock the canopy, and the unintentional opening of the canopy after liftoff.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 4, 2001 · about 8:00 pm local time
- Place
- Bozeman, Montana · Gallatin Field · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Avia Stroitel AC-5m, amateur-built · all AC-5ms on the register
- Registration
- N1635M · no longer on the register · serial 003
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
Prior to takeoff in a powered glider, the pilot opened and closed the canopy a number of times in order to communicate with members of his ground crew. When he was given clearance for departure, he closed the canopy one last time, but inadvertently did not get the latching mechanism fully engaged. After liftoff, as the aircraft climbed to about 30 feet above the runway, the canopy unexpectedly swung open. The pilot's attention was then momentarily diverted to the open canopy, and when he looked back toward the front of the aircraft, it was just about to impact the surface of the runway in a nose-down attitude. It was later determined that he had not reviewed his checklist just prior to departure to ensure that he had accomplished all critical items.
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: commercial pilot
- Ratings: single-engine land; instructor: glider; instrument: airplane; rotorcraft: glider
- Flight time: 2,400 hours in all; 0 in this make and model
- Last flight review: August 23, 2000
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: sngl
- Injury: serious injuries
The aircraft
- Airframe total time: 5 hours
- Last inspection: condition inspection; 5 hours since
- Maximum gross weight: 660 lb
- Seats: 1
- Landing gear: fixed
- Engine: Zanzottera MZ-35 (piston); 0 hours total
The flight
- Departed from: Bozeman MT at 8:00 pm
- Flight plan: none
- Runway 30, 9,500 ft by 150 ft
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 32°F (0°C), dew point 0°F (-18°C)
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.