The Occurrence
On 6 May 2023, at approximately 0910 Pacific Daylight Time, a Mustang Helicopters Inc. Airbus Helicopters AS 350 B3 (registration C-GUXR, serial number 3475) was undergoing maintenance ground run operations at Smithers Airport (CYYD), British Columbia. One pilot was on board, and two maintenance staff members were standing on the ground near the helicopter’s left cargo door.
During the third maintenance ground run, the pilot increased the engine power from IDLE to FLT (flight idle) while monitoring the instruments. As the helicopter reached flight idle, it suddenly began an uncommanded rotation to the right. Upon recognizing the rotation, the pilot moved the engine control to IDLE, turned off the fuel, and applied the rotor brake. The helicopter came to rest after completing approximately 540 degrees of rotation.
Injuries and Damage
Both maintenance staff members were struck multiple times by the tail rotor. One sustained serious injuries, and the other was fatally injured. The pilot was uninjured. The helicopter received minor damage.
Investigation Status
The Transportation Safety Board of Canada (TSB) conducted a class 3 investigation into this occurrence. Class 3 investigations analyze a small number of safety issues and may result in recommendations, typically completed within 450 days.