Amateur-built VORTEX accident near Chinook, Montana, June 9, 1998
On June 9, 1998 at about 11:45 am local time, a amateur-built VORTEX (gyroplane), registered N9261N, was destroyed in an accident near Chinook, Montana. It was a personal flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to maintain aircraft control for an undetermined reason.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 9, 1998 · about 11:45 am local time
- Place
- Chinook, Montana · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built VORTEX
- Registration
- N9261N · no longer on the register · serial 001
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The private pilot, who was the builder of the gyroplane, had logged about 21 hours of flight time in gyroplanes, but did not have a gyroplane rating. A witness observed the gyroplane's departure and climb-out from the airport. When the gyroplane was approximately 400-500 feet AGL, the witness observed the nose pitch down slightly, then rapidly upward about 40 degrees, then down rapidly about 40 degrees below horizontal then back up as before. The witness said the gyroplane then seemed to fall nearly vertically downward to the ground, and speculated that there was some sort of catastrophic failure to the aircraft. FAA inspectors, however, found no evidence of inflight breakup, or a main rotor blade strike of the empennage.
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: 2,322 hours in all; 21 in this make and model; 7 in the last 90 days
- Medical certificate: Class 3 (valid medical--w/ waivers/lim.)
- Seat: frt
The aircraft
- Last inspection: annual inspection, May 5, 1998
- Maximum gross weight: 760 lb
- Seats: 1
- Landing gear: fixed
- Engine: Rotax 582 (piston); 0 hours total
- Fire on the ground
The flight
- Departed from: S71 at 11:40 am
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 36°F (2°C), dew point 34°F (1°C)
- Altimeter: 29.00 inHg
- Observation at 11:56 am from KHV
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.