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

The US Federal Aviation Administration says there's a computer glitch in a 787 that was run continuously for 248 days.

It caused the plane to lose power as generator units simultaneously went into failsafe mode.

The administration says this could happen at any phase of flight in a plane that relies extensively on electricity from its own generators.

According to Boeing's records, all jets in service have been powered off and turned back on as part of routine maintenance, so there's no immediate danger of a plane in service losing power.