HALIFAX — A hairline crack has been found in the main gearbox mounting feet on a Cougar Helicopters chopper based in Halifax.

The St. John's, N.L., company announced that Cougar engineers found the crack on a Sikorsky S-92 during an inspection that followed a routine training flight Monday.

Sikorsky and the Federal Aviation Administration in the United States recently issued an airworthiness directive to mandate visual inspections of the mounting feet after every 10 hours of flight.

Cougar said the main gearbox on the helicopter was removed and would be replaced.

It said it was working closely with Sikorsky to determine what factor or factors led to the problem.

A Cougar S-92A crashed into the ocean off Newfoundland last March, killing 17 of 18 people on board.

The Transportation Safety Board is still investigating the cause of the crash. It has already announced that the pilots reported a loss of oil pressure in the gear box before losing control of the chopper as it ferried workers to offshore production platforms.

An inquiry into the tragedy has begun in Newfoundland.