NYC99LA115 · Hammond TWINSTAR GYROPLANE TWINSTAR G
Hammond TWINSTAR GYROPLANE TWINSTAR G · Accident: loss of control on ground/water during takeoff
From N13 to an unrecorded destination
Event
- NTSB case
- NYC99LA115
- 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
Hammond TWINSTAR GYROPLANE TWINSTAR G
- Aircraft type
- Hammond TWINSTAR GYROPLANE
- 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
- N6364H
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From N13To 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 · roll/run
- 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 on ground/water
- 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
- Pilot in command › Rotor RPM, not maintained
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The pilot was attempting a takeoff in his gyroplane when the rotor rpm decreased. The pilot continued the takeoff roll to try to increase the rotor rpm. However, the rotor blades began flapping, and finally struck the ground to the left of the gyroplane, causing it to roll over to the left. Winds at the time were from the left, about 90 degrees, at 7 to 10 knots, with reported gusts in the area. The private pilot had 87 hours of flight time in model. He was rated in airplane category aircraft, but not in rotorcraft category aircraft. According to 49 CFR Part 61.31(k)(2)(i), a rotorcraft category rating and the gyroplane class rating were not required, even though a passenger was onboard, since the gyroplane was not type-certificated. In addition, the operating limitations for the gyroplane did not require the pilot to have an appropriate category or class rating, as well.
Probable cause
The pilot's failure to maintain sufficient takeoff rpm. Factors included crosswind gusts, and the FAA's lack of category and class rating requirements for pilots flying non-type-certificated experimental aircraft.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record NYC99LA115
- Event ID
- 20001212X18868
- Case number
- NYC99LA115
- 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: ea4ad49c0955437a9508436902f860c32791c0c2125461419ef003cc4dc79807; retrieved 2026-09-21T11:04:04.899Z.