Date & Time:
Jan 31, 2022 at 1222 LT
Type of aircraft:
Beechcraft 350 Super King Air
Operator:
Registration:
C-GEAS
Flight Phase:
Landing (descent or approach)
Flight Type:
Training
Survivors:
Yes
Schedule:
Trenton - Thunder Bay
MSN:
FL-17
YOM:
1990
Country:
Canada
Region:
North America
Crew on board:
3
Crew fatalities:
0
Pax on board:
0
Pax fatalities:
0
Other fatalities:
0
Total fatalities:
0
Circumstances:
Owned by Air Tindi, the airplane (coded as CT145D by the RCAF) was operated by the 8 Wing Multi Engine Utility Flight (MEUF). The mission consisted of a multi-day cross country training and familiarization trip with three military aircrew members onboard. The accident happened on the first segment of the mission. The aircraft departed 8 Wing Trenton on an Instrument Flight Rule flight plan, with a destination of Thunder Bay Airport, ON. Following a routine climb out and cruise, the aircraft was cleared for the RNAV Z 25 instrument approach into Thunder Bay. The aircraft was configured for the approach and flown utilizing automation. Approximately two miles back from the runway and with the airport visual, the pilot elected to continue the remainder of the approach manually and disconnected the autopilot. As the aircraft crossed over the runway threshold with a height above ground of approximately 50 feet, the pilot flying moved both power levers to idle with the intent of landing. A left yaw quickly developed followed by a rapid drop of the left wing. The pilot monitoring the approach took control and initiated an overshoot, however the left wing tip contacted the runway surface and the aircraft progressed uncontrolled into the snow-covered infield. Once the aircraft came to rest, the three crew members egressed the aircraft. The aircraft sustained very serious damage and the pilot flying suffered a minor injury, while the other crew members were not injured.
Probable cause:
The investigation determined that the aircraft was documented serviceable prior to the flight and that no issues were evident to the crew before the power levers were brought to idle. Post-accident analysis of the recovered aircraft flight data and componentry determined that a part within the propeller speed governing system failed to function nominally, specifically the beta valve or the beta solenoid. This led to the left-hand propeller windmilling, which was the most likely cause of the accident. Since the beta valve was damaged and internal parts lost during the accident sequence, a definitive determination of its serviceability could not be conducted.
Final Report:
C-GEAS.pdf426.86 KB
