United States regulators have approved a plan by the American aircraft manufacturer, Boeing, to re-design the batteries on its Dreamliners after problems with them led to the the entire fleet being grounded In January.
The internal batteries on two separate aircraft short-circuited, causing a small fire on one plane and forcing another to make an emergency landing.
The US airline regulator has approved a plan to redesign the lithium-ion batteries of the Boeing 787 Dreamliner.
The Federal Aviation Administration (FAA) approved Boeing's plan, which it said requires it to "conduct extensive testing and analysis".
But the FAA gave no indication of when the planes might be allowed to carry passengers again.
Air New Zealand said in January that its order of 787 Dreamliner jets will not be affected despite the safety checks which have halted deliveries of the Boeing planes.
The Air New Zealand Dreamliners were still expected to arrive on schedule in the second quarter of next year, it said.
All 50 Dreamliners in operation were grounded after the batteries emitted smoke on several separate occasions.
The plane is the first plane in the world to use the lithium-ion batteries, which are lighter, hold more power and recharge more quickly.
The FAA has also approved limited test flights for two aircraft to test the changes in the batteries.
"This comprehensive series of tests will show us whether the proposed battery improvements will work as designed," said US Transportation Secretary Ray LaHood. "We won't allow the plane to return to service unless we're satisfied that the new design ensures the safety of the aircraft and its passengers."