The manufacturer of the Air New Zealand Airbus that crashed into the Mediterranean in 2008 killing seven people says the findings of a French investigation confirm the plane was not at fault.
Five New Zealanders and two German pilots were killed when the Airbus A320 plunged into the sea near Perpignan on a test flight off France's Mediterranean coast.
The pilots had been conducting a low-speed, low-altitude test after a technical overhaul of the plane.
In its final report, the French air accident investigation agency, BEA, says the pilots were not qualified to do such a test.
It also says the incorrect washing of the plane by ground crew caused water to enter sensors that measure angle of flight.
BEA director Jean-Paul Troadec says the water in the sensors turned to ice in mid-air, so the pilots had no warning that the plane was about to stall.
Airbus spokesperson Stefan Schaffrath told Morning Report that the report shows the sensors are perfectly designed for safety, but clearly the recommended maintenance procedures were not followed.
Mr Schaffrath says Airbus will be studying the report to see what safety improvements can be made.
'Poor coordination' a factor
Mr Troadec said a contributing factor was poor coordination between the German pilots and the Air New Zealand pilot overseeing the test. He has recommended regulation of demonstration flights and pilot training.
Aviation expert David Kaminski-Morrow from the magazine Flight Global told Morning Report the disaster was the result of a combination of problems.
He says that the pilots were not adequately trained to do that type of test, but that they might have got away with it if the sensors had not malfunctioned.
Mr Kaminski-Morrow says the report exposes the poor regulation of such flights - a view shared by New Zealand's Transport Accident Investigation Commission.
The commission's chief investigator, Tim Burfoot, whose staff assisted the French investigation, says the report's recommendations could prevent a similar accident in the future.
Captain Burfoot says aviation authorities and airline operators are already discussing regulation.
Air New Zealand supports call
Air New Zealand says it supports the call for greater regulation. In a written statement, chief executive Rob Fyfe says that, while the airline was operating in line with industry standards, a regulatory framework will cut the chance of such a disaster happening again.
Mr Fyfe says the report's findings will bring some closure for the victim's families and colleagues.