Published: 9:39PM Thursday November 19, 2009
Source: NZPA
Source: Reuters
A year after the crash that killed five New Zealanders and two Germans in France, aircraft maker Airbus is wrestling with what to do about poorly executed flight tests of jetliners emerging from major overhauls.
Spurred by the November 28 crash near Perpignan of an Air New Zealand Airbus A320, operated by XL Airways Germany, Airbus has revised rules for its own cockpit crews checking the safety of newly delivered and overhauled planes.
The Airbus was performing flight tests off Perpignan before it was to be formally returned to Air New Zealand. It was being flown by two German pilots from XL Airways.
Flight tests are essential after extensive overhauls, called "heavy checks," in which links between cockpit instruments and flight-control surfaces are refurbished or replaced.
Once the work is finished, the aircraft must be tested and flown without passengers to ensure its parts have been reassembled correctly and all systems work.
The Wall Street Journal says Airbus has now built on lessons from the Air New Zealand crash.
"Investigators determined that while carrying out a low-speed test at an unusually low altitude, the pilots inadvertently stalled the jet by disconnecting the automatic thrust designed to keep it going at steady speed and attitude," the newspaper says.
"In doing so, they failed to understand how the plane's computers would react."
Airbus is also helping its customers develop tougher standards for how airline pilots should conduct tests to verify proper operation of aircraft following extensive maintenance, the newspaper reports.
Safety experts outlined new rules at an aviation-safety conference in Beijing in a bid to address the problem of pilots getting into trouble when computers or other systems acted up during airborne checks of increasingly complex and automated airliners.
According to the US National Transportation Safety Board, more than one-quarter of commercial aircraft crashes since the late 1990s involved some type of testing or ferry flights without passengers, the newspaper says.
French investigators from the Paris-based Bureau d'Enquetes et Analyses probing the crash have not yet announced a publication date for their final report.
A senior flight-test pilot and manager for Airbus, Harry Nelson, says: "We see a lot of problems with (airplanes) decelerating too rapidly and throwing themselves into a stall situation."
As well as reassessing and tightening internal safety procedures, Airbus has launched its first series of training classes specifically designed to sharpen the flying skills and decision-making abilities of flight-test pilots working for airlines.
The five-day course is intended, in part, to teach them the hazards of testing systems at low speeds.
Advertising