A Super Puma gearbox almost ended up in another helicopter days before it suffered a catastrophic failure causing a fatal crash in the North Sea, an inquiry has heard.

Two pilots and 14 oil workers lost their lives when the AS332-L2 plummeted from the sky off the coast of Peterhead on April 1, 2009.

The gearbox failed as the chopper flew from the BP Miller platform to Aberdeen.

This was as a result of a fatigue fracture on a planet gear in the epicyclic module component of the gearbox.

Yesterday a fatal accident inquiry into the men's deaths heard that the gearbox was almost replaced when problems emerged with the aircraft on March 25.

Engineers from the helicopter operator Bond had to call the manufacturers in France.

Eurocopter specialists were also informed that a metallic particle had been detected

Bond engineers were directed to follow instructions listed in a specific work card instead of the maintenance manual.

It later emerged that Eurocopter experts believed that the chip had been detected in the main gearbox chip detector instead.

Yesterday former Bond maintenance manager, John Crowther, said: "[Senior Engineer] Steven Milne actually called me at home.

"He said, 'I think we should change the gearbox altogether,' and I agreed with him."

Mr Milne, 55, said it was quite unusual to find a particle in the epicyclic module of that type of helicopter and it was the first case that he had heard of at that time.

But he said the issue "was not a cause for great alarm" when the problem emerged in March 2009.

The inquiry continues today