Black box seized after 'technical' failure on Boeing-made LATAM plane

AUCKLAND - New Zealand investigators seized the flight recorder from a Boeing-made LATAM plane, searching for the cause of a mid-air plunge that injured dozens of terrified travellers.

The Boeing 787 Dreamliner was en route from Sydney to Auckland on Monday evening when it lurched earthward without warning, slinging some unrestrained passengers out of their seats and smashing others into the cabin ceiling.

"Everyone started screaming, crying," said Australian receptionist Ellie Addison, one of 263 passengers aboard flight LA800.

"People were launched out of their seats, there was blood pouring from people's faces." 

It is the latest in a string of headline-grabbing safety incidents to trouble US plane maker Boeing.

Both Boeing and Chile-based LATAM Airlines have promised to cooperate with authorities to pinpoint the cause of the unspecified "technical event".

Confusion has clouded early investigations, with both Chilean and New Zealand safety watchdogs suggesting the other nation was taking the lead. 

New Zealand accident investigators said Tuesday they had started gathering evidence, "including seizing the cockpit voice and flight data recorders".

But, a spokesman added, "it is Chile's investigation". 

Sales administrator Veronica Martinez said it felt like the plane had stopped mid-air, and then "we just plunged". 

Air accident safety investigator Joe Hattley told AFP that technical problems were rare in modern aircraft.

"That flight record will be key to understanding this event," said Hattley, who also teaches at the University of New South Wales in Australia. 

"It will tell investigators if it was an atmospheric event or a technical problem with the aircraft."