Rudder could be cause of Air France crash, pilots and experts say
There's been a pattern of irregularities linked to the tail fin, but Airbus says it's too soon to know.
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But NTSB investigators note that the investigation took almost three years, and they say potential computer problems were thoroughly investigated at the time.Skip to next paragraph
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"In that case, the flight recorder was the source of detailed information that indicated how rapidly and frequently the rudder was moved. Then it was just a matter of aerodynamic calculations to see [what caused the tail to tear off,]" says Richard Healing, who was a member of the NTSB at the time of the investigation. "We were totally convinced the pilot's feet were on the pedals and he was moving the controls manually."
But the A330 pilot and others note that Airbus's computerized flight controls are highly complex and have resulted in other uncommanded rudder and other component movements.
Two other unusual incidents
In addition to the rudder incidents documented by American Airlines pilots prior to the 2001 crash of AA587, last year two Qantas Airlines Airbus 330s experienced uncommanded pitches nose-downward.Nine months before that, in January 2008, an Air Canada Airbus 319 also "experienced a sudden upset when it rolled uncommanded 36 degrees right and then 57 degrees left and pitched nose-down," according to a report on file at the NTSB.
As a result, some pilots and analysts would like to see a more thorough investigation of whether a potential computer glitch may have played a part in the dramatic rudder movement during the AA587 crash. They believe that could hold a key to help understand whether a similar "uncommanded" movement could have played a part in the Air France plane suddenly breaking apart and losing its vertical stabilizer mid-air during a routine flight.
"Airbus has every single incentive to do whatever it takes to find out what could have gone wrong to be sure that information gets in the right hands to prevent further accidents," says Kevin Mitchell, chairman of The Business Travel Coalition in Radnor, Pa. "On the other side of the issue, if they have fundamental structural or design flaws and billions of dollars invested, then it doesn't get any worse in terms of strategic prospects. So organizations like the NTSB and the Federal Aviation Administration must be on the alert for potential conflicts of interests."
Airbus has not returned calls asking for comment on this story. But in a conversation earlier this week, an Airbus spokesman speaking on background cautioned against continued speculation about the cause of the accident.
"All we know at the moment is that, yes, there's a piece of the rudder that's been found and that we know that there were some maintenance messages sent from the aircraft, and one said there was inconsistency with air speed measurements. That's all we know, and it's not enough to build a picture of what happened to the aircraft, which is why it's so important to find the missing black boxes," he said.