The Transportation Safety Board (TSB) says a 2016 helicopter crash near Smithers was caused by a known issue with the helicopter’s hydraulic system, triggered by the pilot.
The Airbus AS 350 FX2 operated by TRK Helicopters went down on a snowy slope with the pilot and six passengers on board on March 16, 2016.
A TSB report on the crash says the pilot was flying low and began descending into a ravine when the helicopter pitched up, rolled to the right and slammed into the slope.
According to the report, AS 350s are prone to a known phenomenon called “servo transparency” that happens when, through a combination of factors, aerodynamic forces on the helicopter’s rotors go beyond what the hydraulic system can handle. When that happens, they will pitch up and roll to the right.
The report found that prior to the crash the pilot was operating with four of the five risk factors linked to that phenomenon, including high airspeed and high gross weight, putting the “helicopter in a flight regime that resulted in servo transparency.”
Although the pilot was able to regain control, the helicopter was flying too low to recover before the crash, it said.
The impact left the helicopter badly damaged, but no one was hurt.
The TSB investigation also found that the helicopter’s emergency locator transmitter failed, owing to undetected wear over time.
According to the report, TRK Helicopters has since updated its training curriculum covering emergency procedures regarding hydraulic system failures and the conditions that can cause servo transparency.