Heli crash shows need for pilot vigilance in mountain terrain: report

Canada’s air safety watchdog has released its report on a helicopter crash between New Denver and Kaslo last spring.

The Transportation Safety Board says the tail rotor strike and rollover of the Kootenay Valley Helicopter’s Airbus AS350 B3 on March 16, 2022 was an example of the need for pilots to be exceedingly cautious when working in mountainous terrain.

“The deterioration of weather conditions or whiteout generated by the helicopter during flight can lead to disorientation and controlled flight into terrain,” says the report, released earlier this month. “Pilots must continuously exercise vigilance to reduce and mitigate the risks associated with changing weather, especially in the mountains.”

The Kootenay Valley helicopter was out from New Denver with a pilot and two Ministry of Transport avalanche technicians conducting avalanche control operations when the accident occurred. The procedure has technicians identifying a likely place to trigger an avalanche and dropping explosives at the site, preventing larger slides from potentially blocking roads.

But the report says the pilot became disoriented right after the technician dropped an explosive charge on the mountainside northeast of New Denver, called London Ridge. They were about 20 feet above the ground when the incident began.

“Just as the pilot lost reference with the ground and flight visibility was reduced, the bombardier deployed the second explosive charge,” says the report. “At this time, the main rotor downwash and prolonged hover over a layer of loose snow created whiteout conditions.”

Blinded by the snow squall of his own making, the helicopter pilot tried to pull away, but the tail rotor struck the ground or a tree. The pilot made an emergency landing – just a few metres away from the dropped explosive charge.

“The main rotor and blades were fractured and the tail boom was partially severed,” the report states. “The helicopter came to rest about 3 to 5 m downslope of the second explosive charge deployed; the charge detonated approximately 2.5 minutes later, but did not trigger a release of the snowpack.”

The pilot and passengers were disoriented and shaken but not injured in the accident. The pilot managed to help his passengers get out of the helicopter and set an emergency beacon. They were picked up a short while later by another local helicopter.

No blame, just recommendations

Because of the straightforward nature of the accident and limited impact to people or the environment, the Transportation Safety Board only conducted a lower-level investigation and report.

“The Transportation Safety Board of Canada (TSB) investigated this occurrence for the purpose of advancing transportation safety,” the TSB website says. “It is not the function of the Board to assign fault or determine civil or criminal liability.”

The board noted the pilot was properly accredited, the avalanche technicians’ training up to date, and the helicopter company has since conducted safety reviews and developed new procedures for preventing similar incidents from occurring.

It’s updated those procedures and briefed all its pilots, the report says.

“Before starting the approach to a blasting site, the crew must hold a briefing to discuss the suitability of the avalanche start zone, current weather conditions, and the adequacy of visual reference for approach, deployment of the charge, and departure from the blasting site,” it says. “If, during the approach phase, a new site is selected, the approach is discontinued. A thorough assessment of the new location is subsequently conducted and briefed, and a new approach is initiated.”

The report also notes the Ministry of Transport examined various aspects of its avalanche control operations after the incident, and “arrived at several findings and recommendations pertaining to the work activity, work conditions, execution, materials and equipment, communications, training, safe-work procedures, emergency procedures, personal protective equipment (PPE), and other factors such as post-occurrence worker assistance, and general coordination and planning,” the report says.

The report also reminds passengers should “use restraint systems as intended so that they can be easily released when required.”

The helicopter sustained heavy damage, and has since been removed from the crash site.

The TSB has concluded its investigation of the incident.

John Boivin, Local Journalism Initiative Reporter, Valley Voice