Airbus Helicopters has provided further details on the changes it made to a key gearbox component on the EC225, expected to be delivered to operators for retrofit in July or August.
The majority of the 11t type’s global fleet was grounded for around 10 months following the second of two North Sea ditchings in October 2012. The cause of the two incidents – which led to a ban on overwater flights – was later traced to failure of the bevel gear vertical shaft in the helicopter’s main gearbox.
EASA approved the modified component on 22 April, which will now be rolled out to operators.
Jean-Brice Dumont, executive vice-president for engineering at Airbus Helicopters, says the alterations to the shaft deal with three issues – corrosion, residual stress and stress hot spots.