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PARIS - French aviation investigators probing the crash of the Air New Zealand A320 into the Mediterranean last November have called for stricter oversight of manoeuvres and training on such handover flights.

The recommendation came in a preliminary report into the Air New Zealand crash and is contained in a 50 page document released in Paris on Tuesday (Wednesday NZ time).

Speaking to the Herald at the release of the report, Paul-Louis Arslanian, Director of the Bureau d'Enquetes et d'Analyses said his office was recommending that such flights have a pre-agreed programme of tasks, and not include any improvised manoeuvres particularly at lower altitudes.

Referring specifically to the Air New Zealand crash, Arslanian told the Herald. "They had some checks to do, they were unable to do these as the flight was shortened so they made a low speed check during approach. Then they lost control of the plane."

"A test check at low speed was supposed to be done during the flight and well, they decided, or to be more specific, they performed it during the approach which is not only low altitude but also as part of a flight which is linked with specific procedures and heavy work load," said Arslanian.

The plane then reared up a steep 46 degree incline before dramatically plunging into the sea.

"We are trying to understand what caused this accident, this is a very complicated investigation, he said.

The BEA has also recommended that prior to such non-revenue flights (flights without passengers) civil aviation authorities ensure 'the qualifications and training of crews' to carry out such manoeuvres.

Although it is still unclear who made which decisions, the report notes that the crew 'had not received any specific training for this type of flight. The Air New Zealand pilot had undertaken two simulator training sessions.'

Questioned on this, Arslanian told the Herald, "The Air New Zealand pilot was prepared for this flight, he received specific training in simulator. He was not in charge of the flight. Technically he was a passenger. In practice, he was in the cockpit and he was discussing with the crew. And he participated in the flight. We have to understand what was his role, and what was his input in the flight," said Arslanian.

The report is the first phase of what is likely to be a lengthy investigation into the cause of the disaster.

The interim document also identifies as a focus of inquiry the possibility that fuselage sensors may have been obscured or affected while the aircraft was being resprayed in Air New Zealand's colours after it had been leased to a German charter airline.

This could have affected the accuracy of the "fly-by-wire" system in which the aircraft's flight stability is automatically determined by its on-board computers, it said.

The crash off Perpignan on France's Mediterranean coast at 4.46pm on November 27 killed five New Zealanders and two Germans.

They were checking the twin-engine airliner before it was handed back to Air New Zealand by XL Airways Germany, which had leased the craft.

It had just been resprayed by EAS Industries, a Perpignan firm.

The crash was a mystery, because the plane had been doing a routine handover test flight over the sea and had not issued any distress call.

The probe by the BEA is separate to an investigation of involuntary homicide, being conducted by the Perpignan public prosecutor's office.

The BEA report was delayed by difficulties in getting data from the two "black boxes" that divers recovered from the wreckage at a depth of 40m.

Last month, the A320's makers, Airbus, issued a safety recommendation to all 218 of its customers.

It warned them not to obscure the sensors during paint work, and reminded them that test flights should be conducted safely, and low-speed manoeuvres should not be conducted at low height.

The A320, a single-aisle aircraft seating 150 passengers is a workhorse of the air industry.

The high-tech "fly-by-wire" avionics - initially viewed with suspicion by pilots when they were introduced in 1988 - are a big factor in its success.

According to its makers, 1960 A320s were in service at the end of last year, with 155 airlines.

Four of the five New Zealanders killed in the crash worked for Air New Zealand.

They were Captain Brian Horrell, 52, from Auckland, and engineers Murray White, 37, also from Auckland, and Michael Gyles, 49, and Noel Marsh, 35, both from Christchurch.

The fifth was Jeremy Cook, 58, from Wellington, a Civil Aviation Authority airworthiness inspector.

The two Germans pilots, who were flying the aircraft when it crashed, have not been publicly named.