Hairline crack found in St. John's chopper

A Cougar Helicopters official confirmed Thursday that one of its helicopters has been grounded since Tuesday, when a hairline crack was found in the aircraft that the company uses to transport workers to offshore oil platforms east of St. John's.

Christian Kittleson told CBC News that, during a post-flight inspection, a Cougar employee found a crack in a footing that attaches the main rotor's gearbox to the Sikorsky S-92A's body.

"During a scheduled inspection of an aircraft located in St. John's, Cougar engineers identified a single hairline crack in the mounting feet of the main gearbox," said Kittleson. "This is not a new issue, this is an issue that the manufacturer is reviewing as we speak. Immediately once we found the fracture that gearbox was removed and it will be replaced."

It’s the same type of helicopter that crashed into the ocean 55 kilometres southeast of St. John’s last winter, killing 17 of the 18 offshore oil industry workers aboard.

Cougar Helicopters, which operated the chopper that crashed near Newfoundland and Labrador last March 12, also reported Nov. 2 that a hairline crack had been found in a gearbox mounting foot on one of the S-92As it operates in Halifax.

"There have only been two instances of this happening with us," Kittleson said Thursday.

Four feet attach the main gearbox to the body of the helicopter. The gearbox drives the chopper's main rotor blades.

The European Aviation Safety Agency issued an emergency directive last Oct. 24 saying cracks had been found in parts of the Sikorsky S-92A that attach the main gearbox to the chopper's body. In one case, a gearbox foot was fully detached from a chopper operating in Europe.

EASA says the problem could lead to loss of control of the helicopter.