# Accident 20060803024249A: Bell 206L1, Busby, MT, August 3, 2006

- Type: FAA accident report (Accident/Incident Data System), as reported
- Date: August 3, 2006, 12:30 local time
- Place: Busby, MT
- Damage: Substantial damage
- Phase of flight: Pwr Off Vert Land/Autorotate
- Operating rules: General operating rules (Part 91)
- Location: 45.5369° N, 106.9550° W: From the FAA
- Nearby events: https://openairdocs.org/map.md?lat=45.5369&lon=-106.9550&mi=10
- Aircraft: N5746N (not matched to a registry record)
- Reported make and model: BELL 206L1
- Reported engine: ALLSN 250C30P
- People aboard: 4
- Fatal injuries: 0
- Pilot flight hours: 5,500 total, 2,000 in this make and model, 83 in the last 90 days
- NTSB investigation: [NTSB SEA06TA153](https://openairdocs.org/ntsb/SEA06TA153) (OpenAirDocs)
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/20060803024249A

## Narrative

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

(-23) ON AUGUST 3, 2006, ABOUT 1230 MOUNTAIN DAYLIGHT TIME, A BELL 206L-1, N5746N, LANDED HARD DURING AN EMERGENCY LANDING FOLLOWING A LOSS OF ENGINE POWER NEAR BUSBY, MT. THE COMMERCIAL PILOT AND THE THREE PASSENGERS WERE NOT INJURED. THE HELICOPTER, REGISTERED TO TS AVIATION OF WORLAND, WY, AND UNDER THE OPERATIONAL CONTROL OF THE BUREAU OF INDIAN AFFAIRS, U.S. DEPARTMENT OF THE INTERIOR, SUSTAINED SUBSTANTIAL DAMAGE. VISUAL METEOROLOGICAL CONDTIONS PREVAILED AND A COMPANY FLIGHT PLAN WAS FILED FOR THE LOCAL PUBLIC USE FLIGHT. THE PURPOSE OF THE FLIGHT WAS TO PERFORM AERIAL WILDFIRE RECONNAISSANCE. THE PILOT REPORTED THAT THE ENGINE FAILED DURING PERFORMANCE OF A POWER ASSURANCE CHECK. PRIOR TO BEGINNING THE POWER CHECK, THE PILOT ESTABLISHED STRAIGHT AND LEVEL FLIGHT AT 90 KNOTS AND 8,000 FEET MSL (ABOUT 5,000 FEET AGL). HE INCREASED COLLECTIVE, THE HELICOPTER BEGAN TO CLIMB, AND AT APPROXIMATELY 8,300 TO 8,400 FEET MSL AND A TORQUE READING OF 95%, THERE WAS A LOUD GRINDING NOISE AND THE ENGINE LOST POWER. THE PILOT ENTERED AN AUTOROTATION. HE HAD DIFFICULTY STABILIZING THE ROTOR RPM DURING THE INITIAL STAGES OF THE AUTOROTATION, BUT HAD ESTABLISHED A STEADY-STATE AUTOROTATION PRIOR TO DESCENDING BELOW 500 FEET AGL. DURING TOUCHDOWN IN AN OPEN FIELD, THE MAIN ROTOR STRUCK AND SEVERED THE TAIL BOOM.

## 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 SEA06TA153](https://openairdocs.org/ntsb/SEA06TA153), Aug 3, 2006: Bell 206L-1 (N5746N), Busby, MT, substantial damage. Probable cause: The improper overhaul of the turbine assembly by maintenance personnel, which resulted in failure of the turbine and a total loss of engine power. A contributing factor was the pilot's misjudgment of…

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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