Leading Australian aviation correspondent Steve Creedy, says in The Australian this morning that air safety investigators are expected to look at problems that sent a Qantas A330 on a wild ride over Western Australia last year as they attempt to solve the mystery behind this week's Air France crash.
Creedy says that the Qantas incident last October and another in December last year also involving an Airbus 330 near Western Australia, involved a problem with a unit called an air data inertial reference unit, which prompted flight control computers to twice pitch down the nose of one of the jets, but fast action by the crew limited the extent of the plane's fall, although 14 people were seriously injured.
The incidents raised questions about a potential wider problem with ADIRUs, which collect raw data on parameters such as air speed, altitude and angle of attack, and process the information before sending it to flight computers.
After the Air France disaster, The Seattle Times reported yesterday that experts were already examining these malfunctions, but Qantas played down any connection between the incidents and the Australian Transport Safety Bureau said it had no plans to include the French crash in its investigation of the local malfunctions.
One reason for this is the planes involved in the Australian incidents were the bigger A330-300s, rather than the 200 series involved in the Air France disaster and it is understood their ADIRUs are made by a different manufacturer to the ones in the French Airbus.
A Qantas spokesman said the ADIRU problem was extremely rare, adding, "To date, the aircraft involved has operated without incident since it returned to service," referring to the plane involved in the October incident.
The loss of the Air France plane after flying through a storm has marred an otherwise good safety record for the A330 family, with more than 600 A330s in service with 72 operators around the world.
Between them, they have logged 13 million flight hours and 3.3 million flights, although notable incidents include the Qantas incidents, a crash soon after take-off during Airbus flight trials in 1994 that cost the lives of seven crew, and a Dragonair encounter in 2003 in which severe turbulence injured 15.
But what had until now been the most spectacular incident occurred in 2001 when an A330-200 glided for 120km without power and landed safely in The Azores after it ran out of fuel over the Atlantic.
What happened in the latest incident is still in the realm of speculation but experts and pilots doubt a lightning strike alone would have brought down the Air France plane with planes often struck by lightning and estimates are that jetliners average one to two hits a year, rarely disastrous.
Modern jetliners are designed so that electricity from a strike flows over the skin of the aircraft and exits though another part of the aircraft, often the tail, with shielding and surge protectors also guarding critical interior components against induced currents.
A former A330 pilot said yesterday that strong turbulence mentioned by the Air France captain in his last message could have been responsible for the aircraft breaking up if load limits on the plane had been exceeded."When you're going through the edge of the (storm) cell, you can sometimes go from a sudden downdraft to a sudden updraft," he said.
Wednesday, 3 June 2009
Air France crash investigation may include Qantas A330 incidents
Source = e-Travel Blackboard: J.A.J