20060803024249A

Accident · Substantial damage

FAA accident report · Bell 206L1 · Busby, MT · August 3, 2006

Date
August 3, 2006 · 12:30 local
Place
Busby, MT
Phase of flight
Pwr Off Vert Land/Autorotate
Operating rules
General operating rules (Part 91)
Damage
Substantial damage
Aircraft
N5746N
NTSB investigation
NTSBSEA06TA153
Reported as
Bell 206L1
Reported engine
Allison 250C30P
People aboard
4
Fatal injuries
0
Pilot’s flight hours
5,500 total2,000 in this make and model83 in the last 90 days

From the FAA’s Accident/Incident Data System (AIDS), through its Aviation Safety Information Portal, as reported. The NTSB investigates accidents separately, and its record of an accident is the fuller one. The aircraft is matched to the registry 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.

What happened

The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.

(-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.

As the FAA filed it

(-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.

NTSB investigation

The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.