Maintenance guidelines introduced since the 2009 North Sea helicopter disaster would have led to the immediate grounding of the doomed Super Puma.
Changes to a key task card made by manufacturer Eurocopter just three months after the fatal crash “removed any ambiguity” about how engineers should have responded to the discovery of a metallic particle in the aircraft’s gearbox, a fatal accident inquiry (FAI) heard yesterday.
Operator Bond’s maintenance manager, Ronald Wright, said the revised guidance meant the detection of any magnetic particle more than 2mm long would mean a helicopter being removed from service.
The inquiry at Aber-deen’s Town House was told the aircraft’s main 77-volume maintenance manual advised thorough checks for the presence of other magnetic particles.
But these were not mentioned on the “trouble-shooter” provided by Eurocopter and Mr Wright, 48, said he was unaware of them at the time.
The task card used by Bond’s team featured a flow chart for identifying particles and deciding what to do about them.
It pointed to the foreign body being silver or cadmium plating, rather than nickel or carbon steel and, because it was 3mm long, the manufacturer’s recommendation was to carry out extra inspections of the gearbox at shutdowns during the next 25 flying hours.
Mr Wright said: “We just followed the instructions that were given to us by Eurocopter.”
He admitted to having concerns of his own, however, and said he carried out various standard checks for signs of any more particles in the aircraft’s transmission.
Speaking on the sixth day of the inquiry into the accident, which killed two pilots and 14 passengers when the AS332 L2 Super Puma plunged into the sea en route to Aberdeen on April 1, 2009, Mr Wright said: “I asked myself if I would be happy getting into that aircraft and the answer was no.”
Asked by fiscal depute Geoffrey Main if evidence of more metal or a different flow chart outcome would have led to a swift grounding, he said: “I would not have hesitated in having it removed from service.”
The helicopter remained on an increased level of monitoring up until the day of the accident, which happened about 31 flying hours after the discovery of the metal particle.
Mr Wright gave a detailed account of his response to finding the tiny metal fragment on March 25, 2009.
He said it was not unusual for such particles to be generated after the routine replacement of parts. The helicopter had a new rotor head fitted on March 1, 2009.
The inquiry continues today.