KEY POINTS:
Airlines round the world are worried that the Air NZ plane crash in France may have been the third incident in as many months to be caused by a defective flight-control computer.
The Herald on Sunday has learned that forensic investigators have set aside a hangar in Perpignan
where they will painstakingly piece together the debris, rebuilding the plane like a jigsaw puzzle from the estimated 20,000 fragments still being recovered from the Mediterranean.
Airbus is refusing to comment on possible accident causes, prolonging uncertainty for the families of the seven dead, and also for airline pilots and engineers who want to avert further incidents.
Amid dismay at delays extracting any information from two recovered flight recorders, New Zealand's top air crash investigator has publicly emphasised the importance of arriving at an explanation for the accident to prevent a repetition.
Tim Burfoot, the Transport Accident Investigation Commission chief investigator, said European investigators were "going through protocols to comply with French law" before returning the recorders to the American manufacturers, Honeywell.
"If there's any information on them, Honeywell will have the technology to get it," he said. "But if we can't get anything off them, it will be a very drawn-out process of trying to piece together information from the remains of the aircraft."
He added: "It is important that we are able to draw some lessons from this accident."
Seven people died - five New Zealanders, including Air New Zealand pilot Brian Horrell and engineer Noel Marsh, and the two German pilots - in last month's crash during a post-maintenance flight.
Witnesses said the plane dived, then attempted to climb sharply, before banking hard into the sea.
It was the third Airbus incident in three months in which erratic manoeuvring was reported.
Around the world, safety experts and airlines are "closely monitoring" the investigation to find out whether the crash involved a problem with the plane's flight-control computer, the Wall Street Journal reported this week. The lack of progress was described as "troublesome".
In the preceding months, two larger Airbus models had also suffered incidents in which flight-control systems malfunctioned, though they had not ended in tragedy.
In October, 40 passengers and crew were injured when a Qantas Airbus A330 lost altitude after going into a dive en route from Singapore to Perth.
Preliminary investigations have found that a problem with the computerised flight controls appears to have caused the dive. European regulators issued a safety directive this month, about corrective procedures Airbus pilots should use in such circumstances.
In Auckland, an Air NZ spokeswoman condemned "speculation" by unnamed sources as unhelpful to investigators and distressing to the families.
"The French authorities have spared no effort or expense and we fully acknowledge that they have a due process to go through to determine the cause of the accident," she said.