Air NZ to shut down Dreamliners every 3 months

Reflected on the tarmac, Air New Zealand staff work around the new Boeing 787-9 Dreamliner. Photo / Peter Meecham

Air New Zealand will join other airlines and shut down Dreamliners completely every three months after tests exposed a problem that could cause the plane to lose all electrical power and a loss of control.

The United States Federal Aviation Administration said laboratory tests by Boeing had exposed a computer glitch in a 787 that was run continuously for 248 days and could cause it to lose power as generator units simultaneously went into failsafe mode.

The administration said this could happen at any phase of flight in the plane that relies extensively on electricity from its own generators rather than using pneumatics to power hydraulics and other equipment.

The FAA directive requires operators of the plane to periodically shut off power completely to planes during maintenance while Boeing develops software to fix the problem.

Air New Zealand has three of the planes in its fleet and nine more on order.

The airline said the FAA order required it to undertake a "power cycle" every three months.

"Air New Zealand fully complies with all Airworthiness Directives from relevant aviation authorities and this requirement will be incorporated into our ongoing maintenance plans," a spokeswoman said.

The FAA has direct control over United States-registered planes but in practice applies to operators of the aircraft around he would.

The New Zealand Civil Aviation Authority monitors Air New Zealand.

"Air New Zealand is required to incorporate this airworthiness directive into its maintenance schedule. The CAA will test this during the Air New Zealand maintenance control re-certification process this week," an authority spokesman said.

The FAA says the deactivation takes about an hour and costs about $110.

It said the risk to the flying public justified waiving a feedback period from operators.

Nearly 270 Dreamliners have been delivered around the world. They first entered service in 2011 after years of design and production delays. The risk of battery fires in 2013 forced the grounding of the fleet around the world for two months.