CHI90DCD02 · Bell 47G-2
Bell 47G-2 · Accident: in flight collision with terrain/water during takeoff
From No airport to an unrecorded destination
Event
- NTSB case
- CHI90DCD02
- 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 47G-2
- 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
- N90529
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From No airportTo 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 137: Agricultural
- 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
- In flight collision with terrain/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
AFTER REFUELING & RELOADING THE HELICOPTER WITH A SPRAY SOLUTION AT A FIELD SITE, A TAKEOFF WAS INITIATED IN CALM WIND CONDITIONS. THE PLT RPRTD THAT THE LOCATION REQUIRED HIM TO TAKE OFF UPSLOPE. HE STATED THAT THE RPM DROPPED SLIGHTLY, BUT REMAINED IN THE GREEN ARC DURING THE UPSLOPE PORTION OF THE TAKEOFF. AS THE HELICOPTER CROSSED A FENCE & THE TERRAIN STARTED SLOPING DOWNHILL, THE HELICOPTER FLEW OUT OF GROUND EFFECT. THE PLT RPRTD HE LEVELED THE HELICOPTER, THEN BEGAN A SLIGHT DSCNT TO INCREASE RPM & AIRSPEED. HOWEVER, THE ROTOR RPM DECAYED & JUST BEFORE TOUCHDOWN, THE HELICOPTER YAWED 90 DEG TO THE RIGHT. AFTER TOUCHDOWN, THE HELICOPTER ROLLED OVER. DENSITY ALT WAS ESTD TO BE 3216 FT.
Probable cause
THE FAILURE OF THE PILOT TO MAINTAIN ROTOR RPM DURING TAKEOFF. THE HIGH DENSITY ALTITUDE AND UPHILL TERRAIN WERE FACTORS.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CHI90DCD02
- Event ID
- 20001212X23909
- Case number
- CHI90DCD02
- 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 1990-08-26.
- API snapshot SHA-256: e9adea251e51bf84987e7f629f78e7a089ad998bd68390bc0bec9bc848bc6fd7; retrieved 2026-09-23T05:22:52.807Z.