FTW98LA015 · Sego Tool HAWK H2X
Groen Brothers Aviation Sego Tool HAWK H2X · Accident: loss of control in flight during takeoff
From T62 to an unrecorded destination
Event
- NTSB case
- FTW98LA015
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- 0
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Sego Tool HAWK H2X
- Aircraft type
- Sego Tool HAWK H2X
- Category
- Gyroplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N4412X
- Operator
- Groen Brothers Aviation
- Onboard fatalities
- Unknown
- Route
- From T62To not recorded
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Takeoff
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Loss of control in flight
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Production/design personnel › Acft/equip, inadequate design
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
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.
Probable cause
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.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW98LA015
- Event ID
- 20001208X09010
- Case number
- FTW98LA015
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 78dc05e7816a5fac5d7da33795ef09af723e665ccfd52bd80107fee985053a75; retrieved 2026-09-22T18:20:44.725Z.