# Accident 19990923027879A: Bell 47G3B2A, Tremonton, UT, September 23, 1999

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: September 23, 1999, 09:00 local time
- Place: Tremonton, UT
- Airport: Tremonton Municipal Airport
- Damage: Substantial damage
- Phase of flight: Low Level Operations
- Operating rules: General operating rules (Part 91)
- Location: 41.6908° N, 112.2693° W: From the FAA, an estimate near the named town, within about 3 miles
- Nearby events: https://openairdocs.org/map.md?lat=41.6908&lon=-112.2693&mi=10
- Aircraft: N83246, a cancelled registration (https://openairdocs.org/deregistered/N83246-2022-07-30) (OpenAirDocs)
- Registry model: Bell 47G3B2A (registry code 1181025, https://openairdocs.org/model/bell-47g3b2a) (OpenAirDocs)
- Registry engine: Lycoming TVO-435-GIA (registry code 41526, https://openairdocs.org/engine/lycoming-tvo-435-gia) (OpenAirDocs)
- Reported make and model: BELL 47G3B2A
- People aboard: 1
- Fatal injuries: 0
- NTSB investigation: [NTSB DEN99LA168](https://openairdocs.org/ntsb/DEN99LA168) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/19990923027879A

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

(.19) ON SEPTEMBER 23, 1999, APPROX. 0900 MOUNTAIN DAYLIGHT TIME, A BELL 47G3B2A HELICOPTER, N83246, REGISTERED TO AND OPERATED BY THE PILOT, WAS SUBSTANTIALLY DAMAGED DURING A FORCED LANDING FOLLOWING A LOSS OF ENGINE POWER WHILE MANEUVERING 1 MILE NORTH OF TREMONTON, UTAH. THE COMMERCIAL PILOT, THE SOLE OCCUPANT ABOARD, WAS NOT INJURED.  THE AIRCRAFT WAS BEING OPERATED UNDER TITLE 14 CFR PART 137, AND NO FLIGHT PLAN HAD BEEN FILED.  THE FLIGHT ORIGINATED FROM THE TREMONTON MUNICIPLE AIRPORT, TREMONTON, UTAH, SEVERAL MINUTES PRIOR TO THE ACCIDENT.  VISUAL METEOROLOGICAL CONDITIONS PREVAILED.  ACCORDING TO PRELIMINARY INFORMATION, THE PILOT WAS CONDUCTING A REPOSITIONING FLIGHT TO A LOCAL STAGING AREA.  SHORTLY AFTER DEPARTURE, THE ENGINE EXPERIENCED A LOSS OF POWER AND THE HELICOPTER LANDED HARD.  UPON IMPACT WITH THE GROUND, THE MAIN ROTOR BLADES FLEXED AND SEVERED THE TAIL BOOM.     (-23)AFTER TAKEOFF ENGINE BEGIN TO RUN ROUGH AND LOSE POWER, PILOT DECIDED TO LAND IN A FIELD.  ON APPROACH TO THE FIELD THE ENGINE LOST MORE POWER, SO THE PILOT INITIATED AN AUTOROTATION.  UPON CLOSING THE THROTTLE THE ENGINE QUIT.  UPON LANDING THE HELICOPTER ROCKED FORWARD AND THEN THE MAIN ROTOR  FORWARD AND THEN THE MAIN ROTOR BLADES CAME DOWN AND STRUCK THE TAIL BOOM CAUSING SUBSTANTIAL DAMAGE TO THE HELICOPTER. THE CARBURETOR HAD RECENTLY BEEN REPLACED.  FURTHER INVESTIGATION INVOLVING ENGINE COMPONENTS IS PLANNED.

## The NTSB's investigation of this event (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB DEN99LA168](https://openairdocs.org/ntsb/DEN99LA168), Sep 23, 1999: Bell 47G3B2A (N83246), Tremonton, UT, substantial damage. Probable cause: The pilot's failure to maintain rotor rpm while attempting a precautionary autorotation landing. A factor was the loss of engine power for undetermined reasons.

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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