Final moments of Air NZ test flight

FATAL FLIGHT: A screen grab of Air Crash Investigation's recreation of the last dive in the flight of an Air New Zealand Airbus A320 as it crashed near Perpignan in France.
FATAL FLIGHT: A screen grab of Air Crash Investigation's recreation of the last dive in the flight of an Air New Zealand Airbus A320 as it crashed near Perpignan in France.

Pilot error caused an Air New Zealand Airbus to crash into the Mediterranean in 2008, killing all seven aboard, a leading aviation documentary makers says.

The two German pilots and the senior Air New Zealand pilot on the flight deck ignored instructions by air traffic control not to conduct a test flight. They did a crucial test too low, dooming the plane.

The internationally popular programme, Air Crash Investigation has just premiered its latest episode, Deadly Test, in which it examines the Airbus A320 crash.

Quoting Sebastian David, the principal investigator for the Paris-based Bureau d'Enquetes et d'Analyses (BEA), the programme says the pilots trusted the plane too much.

BEA and Air Crash Investigation, made by Montreal based Cineflix Media, virtually excuse Airbus Industries from blame although they do say that hosing down the aircraft had ultimately led to the crash.

Air New Zealand has not responded to requests for comment on the programme. The documentary has no statement from the airline.

The plane crashed into the sea, killing five New Zealanders and two Germans, during an acceptance test out of the southern French city of Perpignan.

The plane had been leased by Air New Zealand to the German airline XL Airways, which was returning it.

It had been repainted at EAS Industries in Perpignan and was being sent on an "acceptance flight" across the south of France.

German pilots Norbert Kaeppel, 51, and co-pilot Theodor Ketzer, 58, were flying, while Air New Zealand

Captain Brian Horrell, 52, of Auckland, ordered the various tests the company required before accepting the plane back.

The programme says the crash was of major significance because the A320 was one of the world's most advanced planes. People needed to know why it crashed.

It shows Horrell sitting in the cockpit third seat ordering tests, including timing the lifting of the undercarriage.

The plane was to fly to the French west coast and on the way Horrell is shown asking for the pilot to conduct a series of steep 360-degree turns at 9500 metres.

But an air traffic controller at Bordeaux denies permission.

"We are not doing this kind of flight," the controller says.

The crew do not argue and instead turn back to Perpignan and begin their descent.

It is off the coast of the city that the crew lose control and the plane stalls before smashing into the sea, killing all aboard.

Cineflix use their trademark combination of actors and computer reconstructions to show the crash vividly - including the reactions of Air New Zealand engineers Murray White, 37, of Auckland, Michael Gyles, 49, and

Noel Marsh, 35, both of Christchurch, and Jeremy Cook, 58, an airworthiness inspector from Wellington, who were in the cabin.

The programme says the BEA examined the flight data recorder and heard Bordeaux tell the crew not to do flight testing in the airspace.

But, the programme says, they then heard "something disturbing" - Horrell continuing to order test manoeuvres on the flight.

"The fact that [air] controller do not allow the crew to do the 360 led to a situation where the crew had to improvise to be able to follow the flight programme," investigator David says.

They did some tests to show that various alarms, such as the over-speed indicator, went off.

They then did a go-slow test which should normally be done at high altitude, but which they were doing coming into Perpignan.

Normally the A320 computer system would have taken over, but, instead, the plane pitched up and stall protection failed.

The investigators found later that both the small angle-of-attack sensors had failed 22 minutes into the flight. It was an unprecedented failure.

"We had to understand the conditions that could have led to this situation," David said.

They initially feared that the paint job at EAS might have blocked the two valves.

But they found that after the plane had been painted there had been some dust on it. Rather than wipe it with dry cloths, they used high-pressure hoses to wash it off.

Water got into both sensors, and at 10,000 metres it froze, making the valve inoperable.

Pilot Kaeppel had tried to fly out of the crisis as it occurred but his efforts were not sufficient, David says.

The programme says the pilots missed a single warning on the instruments - Use Man Pitch Trim.

It should have alerted them that the plane's flight computer was not working and that they should fly it manually.

The documentary says the crew either did not see the warning or did not understand it.

"The two crew members try everything to take control of the aircraft but they did not fully understand the situation," David says.

They trusted the plane too much, he said.

"The crew allowed the speed to get slow because they were confident in the good functioning of the aircraft."

The programme concludes by saying the BEA final report was critical of the washing incident, but that it was the nature of the acceptance flight and the crew behaviour that were behind the crash.