The Transportation Safety Board of Canada reported that the crash of a Bell 206B last May 75 miles north of Fort McMurray in Alberta was caused by the pilot’s failure to recognize that the aircraft was entering a right-quartering tailwind that reduced the effectiveness of the helicopter’s tail rotor.
The helicopter, orbiting at a height of approximately 100 feet, experienced an unexpected right yawing motion from which it was unable to recover. The helicopter descended into a stand of poplar trees 60 to 70 feet tall, coming to rest on its right side. The pilot and a passenger seated in the right cabin seat were killed, while another passenger seated in the left front seat was seriously injured.
The flight, operated by Wood Buffalo Helicopters, was chartered by Alberta Sustainable Resource Development to track discarded caribou radio collars and it included much low-altitude, low-speed flying. There were no indications of mechanical malfunction before or during the flight, and the TSB decided that no physiological factors, including fatigue, played a role in the accident.
The company operating the helicopter conducted an awareness campaign about loss of tail-rotor effectiveness (LTE) after the accident. This involved a safety meeting as well as the creation and distribution of an operations bulletin on LTE and the hazards related to low and slow flying.