Fly-By-Wire Contributed To Air France 447 Disaster 319
Hugh Pickens writes "The Telegraph reports that although fly-by-wire technology has huge advantages, Airbus's 'brilliant' aircraft design may have contributed to one of the world's worst aviation disasters and the deaths of all 228 passengers onboard Air France Flight 447 from Rio de Janeiro to Paris. While there is no doubt that at least one of AF447's pilots made a fatal and sustained mistake, the errors committed by the pilot doing the flying were not corrected by his more experienced colleagues because they did not know he was behaving in a manner bound to induce a stall. The reason for that fatal lack of awareness lies partly in the design of the control stick – the 'side stick' – used in all Airbus cockpits. 'Most Airbus pilots I know love it because of the reliable automation that allows you to manage situations and not be so fatigued by the mechanics of flying,' says Stephen King of the British Airline Pilots' Association. But the fact that the second pilot's stick stays in neutral whatever there is input to the other is not a good thing. 'It's not immediately apparent to one pilot what the other may be doing with the control stick, unless he makes a big effort to look across to the other side of the flight deck, which is not easy. In any case, the side stick is held back for only a few seconds, so you have to see the action being taken.'"
over use of tech (Score:1, Insightful)
Ever think we're relying a little too much on technology these days?
Fly by wire.... (Score:5, Insightful)
When i read the annotated black box transcript a few weeks ago, i asked airplane experts about this. They told me:
If one pilot pulls and the other pushes the stick, there is an optical and audio signal.
Also the person was questioned if he pulls the stick and he confirmed it. Unluckily it was already too late by then.
I am no expert, but the root cause was IMHO the crew ressource management and training problem.
Re:More to it than that (Score:2, Insightful)
Re:Fly by wire.... (Score:5, Insightful)
The advantage would be immediate feedback... You would feel the other guys is acting against you. In this case nobody issued a different command, so no "conflict" was signaled.
The crew didn't recognise the pilot in control was not acting rational. With mechanical controls, somebody might have noticed that he was pulling all the time and acted upon it.
Comment removed (Score:3, Insightful)
Re:Fly by wire.... (Score:5, Insightful)
Yeah, but your version has the unfortunate side-effect of not making a Boeing competitor look bad. Can't have that, you know.
(Seriously, WTF is this summary? Fox News Scare Quotes around 'brilliant'? Really, Slashdot?)
Re:yes, fly by wire downed the plane... (Score:5, Insightful)
Fly by wire means your electric inputs are converted into physical inputs by some other system. The two control sticks could be joined together, and the system would still be fly by wire if there was no mechanical link between the controls and the actual surfaces you are controlling.
So who needs to get a clue now?
Re:Boooo Airbus.... USA! USA! (Score:5, Insightful)
Hi Slashdot... (Score:3, Insightful)
And as there are mostly americans here on slashdot people will be only too willing to drink to anti-European kool aid.
I expected better from slashdot.
Re:yes, fly by wire downed the plane... (Score:2, Insightful)
It sounds like the problem here was that the plane was NOT in it's full fly-by-wire mode. The flight computer had given some control back to the pilots when it lost the pitots, and the pilots screwed it up.
Re:Fly by wire.... (Score:5, Insightful)
When i read the annotated black box transcript a few weeks ago, i asked airplane experts about this. They told me:
If one pilot pulls and the other pushes the stick, there is an optical and audio signal.
Also the person was questioned if he pulls the stick and he confirmed it. Unluckily it was already too late by then.
I am no expert, but the root cause was IMHO the crew ressource management and training problem.
While I agree it was a CRM issue; the control system design contributed to this, IMHO. Just because there is a visual and auditory clue at some point does not mean that is understood and remembered; or that it was even heard on more than a subconscious level. Having a visual clue helps, so when you look at a control you see the actual order to the system, rather than a neutral position. That helps operators realize what the system is doing and will help them realize when something is not in a position they expect for a given situation.
Personally, I prefer Boeing's approach of having the controls positioned where they represent the input the system is receiving, that allows a pilot to scan the controls and develop an accurate mental model of what the plane is being told to do; which they can then determine if it is appropriate for the current situation. Not having that picture requires much more inquiry and analysis which may take critical seconds away from correcting the problem.
This is not a problem unique to the aviation industry; I've seen it happen in others where there are complicated systems that have a myriad of controls and require an good understanding of the current conditions to ensure operators respond correctly. Three Mile Island is a good example of a similar set of conditions that lead operators to make bad decisions that were compounded by the control system design.
Unfortunately, it is far easier to say "pilot or operator error" than fix the underlying causes that lead to that error when they are system control related.
Re:Feedback is important (Score:4, Insightful)
It's the same reason why a motion simulator ride at an amusement park can be so convincing. You feel like you are flying but you are sitting right there. Tilting backwards feels very similar to forward acceleration. Flying in a controlled banked turn feels alot like sitting still.
Re:Fly by wire.... (Score:5, Insightful)
I work in IT security. Looking good/bad (even yourself) is a purely secondary issue, if you take your work seriously.
That work is the reason, i read everything i can about airline incidents. Because their security practices are decades ahead of the one in IT (even with the occasional screwups). Their analyses are usually quite good too. But there is nothing a journalist cannot disfigure, once he sets his mind to it :-(.
Re:Begs the Question? (Score:2, Insightful)
It's not a logical fallacy, the use of the term "begs the question" has meant "raises the question" for quite some time now, it's mostly just pedantic assholes that refuse to recognize the difference.
Attention, screeching children (Score:5, Insightful)
Red herring #1: This isn't news.
--Maybe not to some of us. But TFA is new, and in a more general publication than the sources many of you have cited.
Red herring #2: This is an American anti-Airbus hit piece.
--Probably not. The Telegraph is a UK publication, and the title seems deliberately designed NOT to call out Airbus. See #3...
Red herring #3: The title blames FBW, that is a separate issue from back-driven controls.
--Quite right. Perhaps the author wished to avoid seeming anti-Airbus; perhaps he just wasn't precise in his phrasing. You sure don't have to read far to find out the truth.
Red herring #4: This is bullshit. The pilots fucked up.
--Perhaps you're not familiar with the English phrase "contributed to." It doesn't mean the same as "caused." In any safety-critical occupation, a piece of equipment that obscures the actions of one of the team members impedes the type of cross-checking that was a major reason for using a team in the first place.
No system is perfect. People are perfectly free to say that they think this is a minor issue which will only come up in very rare circumstances, more than compensated for by merits of the side-stick. Others might argue that the risks outweigh the benefits. I am smart enough to know that I am not qualified to have an opinion on the issue.
I'm just tired of the hysteria here.
Re:More to it than that (Score:1, Insightful)
So please kindly Go Fuck Yourself.
Re:More to it than that (Score:4, Insightful)
I concur, fly by wire-by-wire had nothing to do with it. Side sticks are here to stay and popular with more than just Airbus. A linked or back-driven yoke may have helped, but there's a far more compelling argument to be made for having Angle of Attack sensors and feedback.
If there was an Angle of Attack readout on the dash board that likely would have created a cross-check opportunity. The technology has been around for decade, but really hasn't caught on (or been required) commercially.
Re:More to it than that (Score:2, Insightful)
A second warning that doesn't ever sound in safe scenarios (e.g. FALLING, FALLING, FALLING) might just have made them twig to "crap, it really is stalling".
Perhaps your not a pilot, but hearing "STALL, STALL, STALL" is the computer's way of saying "I've lost the ability to generate lift and now we are falling unless you cause the plane to generate lift".
No this accident was a case of idiot pilots who thought their job was to have a good time in the cockpit instead of flying the plane.
Re:More to it than that (Score:5, Insightful)
The first rule is: don't freak out. If you feel like freaking out is OK, then don't be a fucking pilot, mmkay? Pilots who freak out die. It's a time proven observation.
A pilot who doesn't know that the AoA and airspeed are sourced by the same set of vulnerable sensors is silly. Next time when you walk down the jetway have a look on your left before you enter the plane. You'll see the pitot tubes sticking out. As an engineer, they'd be the first things I'd distrust if their outputs would be in disagreement with other sensors. Icing happens all the time, it's more common than uncommon.
Those pilots had perfectly good input from the inertial platform, GPS and perhaps radio altimeter. They should have looked at their fine instruments, determined what their ground track speed was, what the attitude was, and figured out what to do. End of story.
Re:More to it than that (Score:5, Insightful)
Perhaps you're not a pilot too, and if you go read the technical briefs about the crash you'll find that "STALL, STALL, STALL" can be issued by this aircraft even when the aircraft is not stalling, and has no possibility of stalling.
Re:Why all this speculation? The report was clear. (Score:4, Insightful)
1) Only one person can have control of the aircraft at once. When the captain says "my aircraft", the second in command takes his hands off the controls.
2) Pulling back on the stick makes a stall worse, not better. A stall is lack of airspeed. The solution for a stall is to increase airspeed. Either with the engines, or by pushing the stick forward, or both.
Re:More to it than that (Score:5, Insightful)
If the guy flying the plane reacts to the STALL warning going off by pulling the stick back then you are already dead.
It's just a matter of time.
Re:over use of tech (Score:5, Insightful)
Every component in the system introduces the possibility of error, agreed.
People can detect and correct certain classes of error better than machines, but machines can detect and correct certain classes of error better than people.
People can self-repair, to an extent. Blake's 7 Liberator-style auto-repair is still sci-fi. Sadly.
Well-trained humans can identify errors in their training but can also forget the training that is correct. Computers cannot (yet) do either.
A perfect balance is what we need.
Re:Wait for the full report (Score:4, Insightful)
If the crew had diagnosed the situation as a failed pitot tube, all they had to do was to turn the throttle to 85% power, and point the nose up 5 degrees and everything would have been fine. The computer was not providing the angle of attack information to the crew, nor was it giving any indication of the throttle setting. Therefore, there was no way to make see that proper steps were not being followed.
Re:over use of tech (Score:2, Insightful)
First, airliners have no business using joysticks. Flying hundreds of people around is no game. Flying these things is a Team Project so whatever can be done to keep everyone clued in to what's going on, it should be done.
Second, I ALWAYS feel better with a physical connection to the control surfaces...wire or hydraulics. I remember early Blackhawks flying by radio stations, turning upside down and crashing down in southern California. Trusting your life to a computer...which means trusting it with the computer programmers...I don't know.
Third, when the shit hits the fan, it is pitch black outside and you have no horizon and no sense of orientation, you have to be one disciplined mother fucker to keep a cool head. We're talking Chuck Yeager test pilot cool head.
Last, lights flashing, buzzers, etc. sometimes is worse than nothing at all. Browse literature about pilots in Vietnam and you will read many instances of pilots turning off alarms and such because the just confuse the situation. A little bit different situation, but just try getting something done with someone yelling in your ear you are doing it wrong again and again.
I'll take a good old Boeing any day.
Re:More to it than that (Score:4, Insightful)
That's one point against vi in the holy war with Emacs. System operating modes are distracting to humans. A state machine inside a state machine is loading short term memory too much in a critical situation.
Re:More to it than that (Score:4, Insightful)
The computer alerted them that the autopilot was disconnected almost immediately. They also in theory knew they were in alternate law. Why they did what they did? I'm guessing sleep deprivation and inexperience.
Re:over use of tech (Score:4, Insightful)
Re:More to it than that (Score:5, Insightful)
To paraphrase Churchill... Never in the history of aviation blogging has so much crap been said to so many by one who new so little.
Vacuum system on an A330? The only vacuum system on an A330 is the toilet.
The static system worked fine. They knew their altitude all the way to impact.
The pitot was heated. It was heated from the moment the first engine was started, automatically. The pitot design was unable to cope with the amount of supercooled water thrown at it. The subsequent design had problems, too. The current pitots by Goodrich work fine.
Nobody 'put their head in the sand.' They made a fundamental error at the start and then were deeply confused as to what their problem really was.
Seeing you expound an A330 crash based on your light aircraft experience is like watching a model rocketeer tell us what went wrong with Challenger based on his experience with cardboard tubes with fins.
The accident report is painful to read because it was so avoidable. Your post made me as angry as the accident made me sad because you don't know squat about jet aviation yet feel free to tell us exactly what went wrong.