EASA has approved a redesigned version of the bevel gear vertical shaft on the Airbus Helicopters EC225, enabling operators to replace the problematic component from the second quarter.

The certification of the changes is key for the manufacturer and operators, as they hope to eliminate any lingering safety concerns on the Super Puma.

Catastrophic failure of the shaft contributed to a pair of North Sea ditchings in May and October of 2012, and led to the effective grounding of large parts of the EC225 fleet worldwide. The grounding order was only lifted in the third quarter of 2013, following the introduction of a series of temporary fixes for the problem. Operators have only recently fully returned all their aircraft to service.

Airbus Helicopters says production of the redesigned component is already under way, “allowing worldwide implementation on concerned aircraft in service and in production, starting in the second semester of 2014”.

Investigations by the UK Air Accidents Investigation Branch and the manufacturer traced the cracking of the shaft to a combination of corrosion, residual stress and stress hot spots – in one case due to a manufacturing fault.

“Airbus Helicopters has put a very high priority on developing this new shaft for the EC225. EASA’s certification is a major milestone towards getting our customers flying with the final solution,” says Jean-Brice Dumont, Airbus Helicopters’ executive vice-president – engineering.

Source: FlightGlobal.com