AAIB: Gearbox Flaw Caused Bond Helicopter to Ditch (UK)

Bond Offshore Helicopters Ltd., operator of the helicopter that ditched into the North Sea last Thursday, concurs with the initial findings of the AAIB interim Service Bulletin S2/2012 which indicates component failure.

The UK Air Accidents Investigation Branch’s  bulletin states that, “An initial visual inspection of the main gearbox has identified a 360° circumferential crack on the bevel gear vertical shaft, in the vicinity of the weld that joins the two sections. As a consequence of this failure, the main and standby oil pump gears ceased to be driven. During this inspection pump gears ceased to be driven. During this inspection it was observed that the lower part of the vertical shaft was displaced downwards by 6 mm.”

This preliminary engineering investigation is consistent with Bond’s own engineering analysis, writes Bond on its website.

The rotorcraft was on a scheduled flight from Aberdeen Airport to the Maersk Resilient platform, in the North Sea 150 nautical miles east of Aberdeen. On board were two flight crew and twelve passengers. The crew of the aircraft was forced to conduct a controlled ditching following indications of a failure of the main gearbox (MGB) lubrication system and, subsequently, a warning indicating failure of the emergency lubrication system.

After the ditching, all passengers and crew evacuated the helicopter into a life raft and safely returned to Aberdeen. Two passengers sustained minor injuries, according to the AAIB report.

Bill Munro, Managing Director of Bond Offshore Helicopters said, ”The skill and training of Bond’s pilots has been witnessed at first hand. Our passengers can be confident in Bond as the principal crew change operator in the North Sea”.

In the light of the AAIB interim Service Bulletin Bond Offshore Helicopters Ltd. will continue the flight suspension of the EC225 and now in addition the AS332L2 helicopter. Bond Offshore Helicopters Ltd. is working with Eurocopter as a matter of priority in finding a solution that will enable the helicopters to be returned to service, said the company in a press release.

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Offshore Energy Today Staff, May 14, 2012