FTW99LA224 · Bell 47G2
Bell 47G2 · Accident: loss of control in flight while maneuvering
From 1F0 to OKC Will Rogers World Airport (OKC)
Event
- NTSB case
- FTW99LA224
- 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
Bell 47G2
- Aircraft type
- Bell 47
- Category
- Helicopter
- 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
- N1774
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From 1F0To OKC Will Rogers World Airport (OKC), Oklahoma City, OK
- 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
- Maneuvering · hover out of ground effect
- 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
- Pilot in command(cfi) › Rotor RPM, not maintained
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The flight instructor heard 'a banging noise accompanied with an increase of engine rpm and a decrease of rotor rpm' during takeoff from a high hover. The helicopter entered a left turn and the pilot rolled the throttle off to enter an autorotation. The helicopter landed hard with low rotor rpm. The main rotor blades contacted the tailboom, and the skid landing gear collapsed. Examination of the engine, main transmission, and free wheeling clutch revealed no discrepancies that would have prevented normal flight operations. Prior to commencing the planned dual cross country flight, the helicopter's fuel system had been filled. The density altitude was calculated at 3,040 feet. The operator stated that the accident could have been prevented by 'not hovering out of ground effect at maximum gross weight with a density altitude of 3,000 foot, and better RPM control.'
Probable cause
The pilot's failure to maintain rotor rpm which resulted in a hard landing. A factor was the high density altitude.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record FTW99LA224
- Event ID
- 20001212X19516
- Case number
- FTW99LA224
- 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: local date, investigation status. Values present in the bulk record are kept.
- The date is the local date; the NTSB stores the UTC date 1999-08-17.
- API snapshot SHA-256: 12f647cbe9924b6c67241b96617fcf2dfc62039b22e780f9bdbb535a05af5b05; retrieved 2026-09-22T14:16:57.111Z.