Amateur-built HAWK H2X accident near Tooele, Utah, October 15, 1997
On October 15, 1997 at about 8:16 pm local time, a amateur-built HAWK H2X (gyroplane), registered N4412X, was substantially damaged in an accident near Tooele, Utah (Tooele South Army Depot airport). It was a personal flight under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to maintain aircraft control. Contributing was the inadequate design of the flight control systems, resulting in slow response to pilot input.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- October 15, 1997 · about 8:16 pm local time
- Place
- Tooele, Utah · Tooele South Army Depot · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Amateur-built HAWK H2X
- Registration
- N4412X · no longer on the register · serial 201X
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
According to the pilot, he was taking off for one of a series of flight tests. He reported that shortly after liftoff, the gyroplane made an uncommanded roll to the right. The pilot said that he applied full left cyclic and full left rudder, but the main rotor system struck the ground. The main rotor blades separated from the gyroplane and the aircraft came to rest with the fuselage twisted. Postcrash examination of the gyroplane by the design/manufacturing team revealed that the control system design of this aircraft had an inherent lag in time between control input and aircraft response. They found the runway that the gyroplane was taking off from slopped 1.7 to 1.8 degrees to the left. They said that 'the moment the aircraft left the ground, gravity moved the fuselage to the left and the rotor disk to the right.' Subsequently, a right turn was initiated and ground contact was made by the main rotor disk before the pilot's correction inputs could take effect.
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, flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: gyroplane; instructor: instrument airplane; instrument: airplane; rotorcraft: gyroplane; rotorcraft: helicopter
- Flight time: 12,663 hours in all; 6 in this make and model; 48 in the last 90 days; 16 in the last 30 days; 12,478 as pilot in command; 4,865 on instruments
- Medical certificate: Class 2 (valid medical--w/ waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 40 hours
- Last inspection: inspection type not recorded
- Maximum gross weight: 2,600 lb
- Seats: 2
- Landing gear: retractable
- Engine: Chevrolet V-8 (piston); 0 hours total
- Operator: Groen Brothers Aviation INC.
The flight
- Departed from: T62 at 8:16 pm
- Flight plan: none
- Runway 36, 5,000 ft by 100 ft
Weather at the time
- Light: daylight
- Wind: from 300° at 8 knots
- Visibility: 15 statute miles
- Sky: scat at 25,000 ft
- Temperature: 63°F (17°C), dew point 37°F (3°C)
- Altimeter: 30.00 inHg
- Observation at 8:52 pm from SLC, 23 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.