Australia’s Civil Aviation Safety Authority (CASA) has issued an airworthiness directive grounding Robinson R44 helicopters fitted with C016-7 main rotor blades.

The grounding follows a fatal accident on 19 February in New Zealand, where it is suggested the aircraft suffered an in-flight rotor blade failure as a result of cracking.

“To prevent the possibility of main rotor blade separation and consequent loss of the helicopter, further flight is prohibited,” the AD reads.

As a concession, CASA will allow for aircraft in remote locations to make one flight, provided that they complete inspections of the affected blades in accordance with a notice issued by the Civil Aviation Authority of New Zealand in January.

That notice followed an earlier AD from the US Federal Aviation Administration that required inspections on R44 and R22 main rotor blades for signs of possible debonding on the skin-to-spar line.

CASA was not able to say how many aircraft are likely to be affected by the grounding, but adds that the AD will remain in place “until further information is available”.

Source: Flight International