Did Onboard Computers Take Fate of Air France Flight 447 Out of Pilots' Hands?

Could the design philosophy used by Airbus's fly-by-wire electronic flight control systems have been the final death blow to Air France Flight 447? That's the chilling possibility suggested by a recent posting by Information Week blogger Michael Hickins.
Air France Flight 447 used an Airbus A330, which uses a completely electronic fly-by-wire system without manual or hydraulic backups. The leading theory of the cause of the Air France Flight 447 crash is conflicting information from pitot tubes, which are used to transmit flight and wind speed information to onboard computers. While Airbus had begun to replace pitot tubes in May, the pitot tubes had not yet been replaced on the plane that crashed in the Atlantic.
According to a report cited by Hickins, Airbus and Boeing, the biggest rivals in the commercial jet field, have diametrically opposed views on pilot override capabilities. Airbus A320 and newer models include so-called "hard limits" that prevent maneuvers that would overstress the airframe, while Boeing's approach keeps the pilot in charge. While it's impossible to know if a Boeing-style system could have enabled the flight crew of Air France Flight 447 to successfully handle the severe weather existing in the air, some Boeing aircraft have survived stresses well in excess of recommended limits - limits that could not be exceeded if the flight computers are in ultimate charge of the aircraft. Commercial pilots' comments, like the industry itself, are divided over whether the differences in fly-by-wire design make one method ultimately safer than another.
Which approach is better? Informed comments welcome.
Image courtesy CBC.
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JDorfler
June 12, 2009 at 11:06pm
You're exactly right. That's why we let the pilot fly the plane.
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r3dd4wg
June 11, 2009 at 5:38am
When the Airbus, in its infancy, was being demoed for Air France (long long time ago), it crashed landed after overshooting the runway. The test pilot's survived the crash but their careers were destroyed by the Airbus people because they blamed them for the crash. It was later found that the computer controls phucked up. (Someone has to remember this. I'm surprised that the media hasn't dug into the planes history more.)
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JDorfler
June 10, 2009 at 11:22pm
I personally know a lot of pilots. Fixed wing and rotary. I even know a lot of UAV Pilots who fly their birds remotely, but are still in complete control. All these individuals are top notch and know their birds better than any computer can. To take all the control out of a pilot's hands in place of a computer's servoes is a disastor waiting to happen. Oh wait, one just happened. I would feel safer knowing my pilot had complete control on a 30 year old Cesna with nothing but analog controls than a brand new Airbus with all the computing power in the world. I'm pretty sure everyone on flight 447 would now agree with me.
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jwalch.hawk
June 10, 2009 at 7:02pm
Let the pilots fly the planes. If there are too many incidents like the recent incident putting a plane in the Hudson River where the pilots weren't as well-trained as they should have been (and arguably just one of those is too many), then there just needs to be some more careful regulation of the training. It's not really man v/s machine here, popular as the notion might be. It's engineer/designer v/s pilot. Yes, we can and should design incredibly helpful flight systems. But when it comes down to a decision mid-flight, I want the pilot's opinion to have the veto. The pilot is in the plane. The engineer isn't.
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lunchbox73
June 10, 2009 at 6:46pm
I'm more concerned about:
"Two passengers with names linked to Islamic terrorism were on the Air France flight which crashed with the loss of 228 lives, it has emerged.
Air France debris on board a Brazilian Navy vessel
Debris from Air France flight AF 447 has been recovered from the Atlantic
French secret servicemen established the connection while working through the list of those who boarded the doomed Airbus in Rio de Janeiro, Brazil, on May 31.
Flight AF 447 crashed in the mid-Atlantic en route to Paris during a violent storm.
While it is certain there were computer malfunctions, terrorism has not been ruled out."
http://news.sky.com
I thought it was strange that the plane seemed to fanish all over a sudden. Blowing up in mid-flight by a bomb seems more plausible than breaking up from a bad storm. If this story turns into something concrete we should all be worried about how these guys found a way to sneak some kind of explosive on board.
I hope this story turns out to be BS...
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SmoothDrRod
June 10, 2009 at 5:48pm
Airbuses are built with a narrower envelope for manual controllability for a number of reasons but mostly to optimize fuel efficiency and it is done so under the assumption that the vast, VAST majority of the time the flight control computers will be able to see the jet through from point a to b. Manual control of a flight at cruise altitude in severe weather conditions with multiple failures was probably considered to be as likely as the number of things that went wrong with Apollo 13 ;) It's like winning the lottery but go googling or ask captain Liam about what he'd rather fly in asstastic conditions with all the computers functioning It's a stability thing. AF447 most likely will be found to have had just the wrong set of circumstances at the wrong time just like any other airliner crash for the most part. I'd argue that a 777 (the nearest Boeing equivalent) would have been easier to handle, more durable, and more likely to have survived all things being equal.
I hold no degrees in aeronautic engineering, mechanical engineering, etc but I have a derrièrethat has been in severe turbulence on an a340 and a 777 and in the cabin the 777 is MUCH more confidence inspiring handling and noise.
PS It looks like that tail was ripped clean off from excessive rudder input IMHO not too dissimilar from the a300 that went down i New York November 12 2001
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horzo
June 10, 2009 at 4:31pm
The media is full of bad info when it comes to flying.
One of the few worthwhile media sources on commercial aviation is available here: http://dir.salon.com/topics/ask_the_pilot
Written by an active airline pilot, and well worth reading.
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robduffy
June 10, 2009 at 3:08pm
Hi,
Your post is unfortunately factually inaccurate. The airbus features several states, or laws, in which restrictions on the pilot's inputs are progressively removed Airbusdriver.net, AIRBUS FLIGHT CONTROL LAWS
The automated communications from the onboard systems indicate that the aircraft was placed into alternate law allowing the pilots near full control of the aircraft shortly before the last transmission. The aircraft is automatically placed in alternate law if there is a discrepancy between the speed indications that come from the pitot tube based systems.
It is also not true that there are no backup or hydraulic systems on the airbus, see the section on mechanical backup in the flight law description. Controlling an aircraft using trim may seem an unresponsive method wen dealing with a light aircraft but on a large commercial aircraft it provides a good level of control in an emergency situation.
I wonder how much research was done before your postulation.
Kind regards.
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Marcus_Soperus
June 11, 2009 at 5:38am
I appreciate the additional information about the Airbus's operation. One has to wonder, though, whether the switch to alternate law happened quickly enough to enable the pilots to deal with what was happening, or whether, as another commenter has suggested, whether there was a terrorist connection with the loss of the flight.
Much depends upon the recovery of the black boxes.
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