Computers Key To Air France Crash 911
Michael_Curator writes "It's no secret that commercial airplanes are heavily computerized, but as the mystery of Air France Flight 447 unfolds, we need to come to grips with the fact that in many cases, airline pilots' hands are tied when it comes to responding effectively to an emergency situation. Boeing planes allow pilots to take over from computers during emergency situations, Airbus planes do not. It's not a design flaw — it's a philosophical divide. It's essentially a question of what do you trust most: a human being's ingenuity or a computer's infinitely faster access and reaction to information. It's not surprising that an American company errs on the side of individual freedom while a European company is more inclined to favor an approach that relies on systems. As passengers, we should have the right to ask whether we're putting our lives in the hands of a computer rather than the battle-tested pilot sitting up front, and we should have right to deplane if we don't like the answer."
Irresponsible headline, summary (Score:5, Insightful)
It's not surprising that an American company errs on the side of individual freedom while a European company is more inclined to favor an approach that relies on systems.
How fond Americans are of reductionist dualities that are unhelpful, misleading and frequently downright dangerous: American pilot with The Right Stuff in an American plane would have saved everyone; dangerous European plane and computer killed hundreds. Oversimplified sniping, or childish fantasy?
If I want real facts on flying, instead of wild-assed pseudo-political trollery, I'll go read Peter Ladkin or Patrick Smith [salon.com]: "The gist of the accident appears pretty clear: Air France Flight 447 was victimized by a terrible storm."
Re:Irresponsible headline, summary (Score:5, Insightful)
Then I thought of Terrain-following radar [wikipedia.org] and realized that things are not always that simple. Quote:
Under these conditions terrain-following radar is a necessity, since a human pilot cannot react quickly enough to changing terrain heights, and is much more likely to cause a crash than an automated system in the same circumstances.
Re:Irresponsible headline, summary (Score:5, Insightful)
I would argue that instead of it being one or the other, it would be better if the inputs could be merged. Humans are generally better at ingenuity (unless the herustics are really good) and computers are generally better at speed of reaction (unless there's a deadlock between threads), but there's no universal rule.
What's really needed is a way for the pilot and the computer to cooperatively function, such that the failure of either at a task is not a catastrophic failure that could destroy the aircraft.
(I can just hear Boeing and Airbus chiming in: "Yeah, yeah, socialists and their cooperatives! Gimmie a good, old-fashioned dictatorship!")
Re:Irresponsible headline, summary (Score:5, Interesting)
Gosh, that was such a terribly worded article summary I can't decide if the author is a regular 'editor' of /. or just a typical reflection of the poor taste and low competence of the /. editors. Would you prefer one lump of incompetence or two with your /. articles?
Anyway, I'd hate to generalize from my poor abilities as a former pilot, but I tend to favor machines over humans. As Einstein noted, there are no limits to human stupidity, but you can design any degree of redundancy you want into mechanical systems. The simple question is cost versus probabilistic safety.
As should be expected from /., the treatment of the design trade-off in the article summary was amazingly shallow. In extreme cases, the designers create planes that cannot possibly be flown by humans. Such fly-by-wire planes may involve control optimization with negative dynamic stability and feedback loops that can only be satisfied at computer speeds. In particular I'm thinking of a fairly recent jet fighter that had to have PROPER corrective feedback something like every tenth of a second.
As regards the storm, I actually came close to getting killed when something like that caught me off guard. Scaling those possibilities up... Well, that's a big chunk of the reason I mostly avoid flying these years.
With regards to planes, my fuzzy recollection is that the DC-10 had the worst safety record for commercial airplanes. However, every time I look at a 747 it boggles my imagination that the thing can fly. Continuing with Airbus, I remember an interesting crash in Nagoya a few years ago that involved the pilots essentially getting into an argument with the fly-by-wire system...
Re:Irresponsible headline, summary (Score:5, Informative)
Extreme cases have been around a long time. The DeHavilland Mosquito was notoriously twitchy (on the other hand, this meant it was unbelievably manoeverable in a dogfight, superior to many fighters) and "flying wings" have existed for longer than the jet engine. Computer control merely makes these economic by having fewer do landscaping.
Nagoya crash (Score:5, Informative)
China Airlines Flight 140 was a route from Taipei, Taiwan to Nagoya, Japan. On April 26, 1994, the Airbus A300 on the route was due to land at Nagoya Airport. The Airbus A300 was completing a routine flight and approach, however just before landing, the First Officer pressed the Take Off/Go-Around button (also known as a TOGA) which raises the throttle position to the same as take offs and go-arounds.
Pilot Wang Lo-chi and copilot Chuang Meng-jung[1] attempted to correct the situation by manually reducing the throttles and pushing the yoke downwards. The autopilot then acted against these inputs (as it is programmed to do when the TOGA button is activated), causing the plane to have a very nose-high attitude. This nose-high attitude, combined with decreasing airspeed due to insufficient thrust, resulted in an aerodynamic stall of the aircraft
-- http://en.wikipedia.org/wiki/China_Airlines_Flight_140 [wikipedia.org]
Re: (Score:3, Informative)
Re:Nagoya crash (Score:5, Informative)
For anyone interested in details of the crashes:
Nagoya, Japan
http://aviation-safety.net/database/record.php?id=19940426-0 [aviation-safety.net]
Mulhouse-Habsheim, France
http://aviation-safety.net/database/record.php?id=19880626-0 [aviation-safety.net]
Re:Nagoya crash (Score:4, Interesting)
the computer refused to let the pilots power up and climb out at the end of the pass.
Citation needed. Jet Engines are typically slow to respond to power. I can't find any source that indicates it was a computer design flaw, rather than electrical or engine flaw. I've looked for OEB 19/1 "Engine Acceleration Deficiency at Low Altitude," which would be relevant, but is apparently unavailable online.
Re: Mulhouse-Habsheim crash (Score:4, Interesting)
You're remembering the popular media speculation of the time, now turned into myth, which, as is often the case, was completely misinformed. See links posted by myself and others above in this sub-thread.
Re:Nagoya crash (Score:5, Insightful)
A big difference is, when you fix an engineering bug, you fix it forever, and can replicate the improvement across the whole fleet. When a pilot makes a nonfatal mistake and learns from it, it adds to his experience. But that all walks out the door when he or she retires.
Re:Nagoya crash (Score:5, Insightful)
That alone makes the anectodal score 1 to 1.
Almost any incident of controlled flight into terrain also counts, since autopilots are very good at not absent-mindedly flying into the ground. Eastern Airlines flight 401, which crashed into the everglades in 1972, is an example of this. The pilot accidently turned off the altitude hold autopilot and the continued to let the plane fly right into the ground.
manual crash (Score:5, Informative)
provide us with 2 examples where the pilot decided to manually override the flight computer and crashed.
Here is 1: http://en.wikipedia.org/wiki/Bashkirian_Airlines_Flight_2937 [wikipedia.org].
Basically, the on-board computers gave the correct advice, but one of the pilots "disregarded the TCAS instruction to climb and instead began to descend, as instructed by the [air traffic] controller, thus both planes were now descending."
The controller was later assassinated by someone who had lost wife and children in the accident.
Re:Nagoya crash (Score:5, Interesting)
It was later shown that FBW was not at fault. The aicraft sunk too fast anyway and by the time the pilots realised it, it was too late.
Jets take a number of seconds to spool up. If yu find a video with sound, you'll notice that the jets spool up just before it hit the trees - some 5s after the pilots commanded them.
AND, there were a bunch of pilot procedural failures at the same time (e.g. never below 100ft AGL), not to mention poor managerial decisions in allowing the flight plan to go ahead in the first place.
Re:Nagoya crash (Score:5, Informative)
That's a falsehood. The crash was caused by multiple pilot errors (failure to heed his instruments; failure to apply power in time - jets do not react instantly, turbo-fans are particularly slow to do so). I've blogged a bit more about the AF296, Airbus tree crash [wordpress.com], including links to a previous /. discussion.
Basically, you're repeating a myth.
On top of that (Score:5, Interesting)
what people are forgetting is that the airbus plane DID return nearly full control to the pilot (nearly because there are still limits to things like how much roll one can request, but these COULD be built in mechanically in the absence of fly-by-wire).
The real issue here is that the computer system detected invalid input and handed the control back to the pilots (under "alternate law" which means most safety rules are disabled), but the pilots may not have had enough information to know whether the control was handed back to them in a safe state, and if not, how to correct.
On top of that, the airplane was flying fairly close to the coffin corner (where the airplane is capable of going too fast and too slow simultaneously, and at this point, in this situation, computers are really helpful). One possible issue is that a gust of wind could have caused "mach tucks" if they were going a little too fast (thus causing downward pressure on the nose during gusts). These could have placed significant stress on the airframe until things started to fail. I have some other theories and observations about debris and ACARS messages, but this isn't the time for that now. All I will say is that all indications are the airplane was flying too fast, and there is NO indication that the instructions Airbus has sent to pilots will remedy that problem because it is unlikely that the pilots would have had sufficient information to act on them.
There are two issues involved here that need additional discussion though:
1) Are airplanes built to withstand forces as well as they used to be? Would, say, a DC8 be able to withstand more turbulance than an A330?
2) Do FBW systems provide sufficient feedback for a pilot to feel the plane? Could accidents be avoided in cases like this by adding additional feedback?
Re:On top of that (Score:5, Informative)
What you claim, is I think in extreme doubt. The airbus is 100% fly-by-wire. When everything is working correctly The airbus allows a pilot an envelope of operation. But it will not allow a pilot to stray outside that envelope. When sensor data is erroneous the envelope is erroneous.
To give you an understanding of this: at the altitude the airbus is flying their is a 25 knot windw between Stall and super-sonic, both of which are fatal if you happen to be in a thunderstorm. So the pilot has almost no controll. He can hardly turn the plane because that would require more thrust than the engines could provide and maintain the 25 knot range. If the instruments reading the air density, air speed and air pressure malfunction or the computer miscalcualtes the pilot is screwed.
My father, god rest his sole, was a lead designer on boeing flight systems and instrumental on it's philosophy. Interestingly he hated computers and loved world war 2. WWII was when designers got lots of feedback on how to design because they made so many errors and planes were pushed to their limits. They did so many post mortems that they learned the process of error free design.
Laugh if you will, but all those software design processes you were taught and all thoe iso compliance rules were not invented by computer scientists. They were borrowed from the airplane industry. There are methods to engineering that work and they learned these by error.
In any case, it was not until the 757 and 767 that boeing had the cahones to build al plane without fully mechanical controls from the cockpit. and even then they let the pilot over ride the computers. By the way there is not one computer. There are 3, and they vote. if one of them disagrees, the other two vote him off the island. They don't trust computers.
This however is changing. Even during my father's tenure they were envious of the weight savings that Airbus was getting with it's fly by wire approach. TO stay competative boeing has had to go that way too.
Re:On top of that (Score:5, Informative)
What you claim, is I think in extreme doubt. The airbus is 100% fly-by-wire. When everything is working correctly The airbus allows a pilot an envelope of operation. But it will not allow a pilot to stray outside that envelope. When sensor data is erroneous the envelope is erroneous.
If you read any of the ACARS data that has been released you would see that you claim is false. The autopilot disengaged, and when the ADIRU faulted, the plain went into ALTERNATE law which does not offer the same envelope protection as normal, because the computer knows that its own inputs can't be trusted. Fly by wire has got nothing to do with it. When it knows the envelope data is erroneous it downgrades its protection. This has got nothing to do with what a Boeing plane will let you do versus Airbus.
Anyway it will take the black boxes to confirm what happened. Anything before that is pure speculation.
Re:On top of that (Score:5, Informative)
What you claim, is I think in extreme doubt. The airbus is 100% fly-by-wire. When everything is working correctly The airbus allows a pilot an envelope of operation. But it will not allow a pilot to stray outside that envelope. When sensor data is erroneous the envelope is erroneous.
Not quite sure. Airbus airplanes have three distinct FBW modes, called "laws." Depending on how you count, there are three or more of them. In Normal Law, it is as you say. The airplane won't let you go into a mach tuck, won't let you stall out by going too slow, won't let you apply the rudder too hard, has strong yaw dampering, etc.
When things go wrong, the control laws are designed to degrade gracefully. To my knowledge, the airbus does not give pilots the choice of flight laws, which is what you are complaining about. If multiple systems fail, the system goes into "alternate law" which provides speed safety and yaw dampering only. Note that in alternate law, any changes that the computer requests can be overriden by the pilot. If ADR systems fail, the speed safety, rudder travel limiter, etc. are also disabled. This means that the plane is being flown pretty much in "direct law" but with yaw dampering.
Additionally, in alternate law, if the plane enters an unusual attitude, flight laws degrade further.
If additional failures occur, the plane reverts to "direct law" which is supposed to be an equivalent to mechanical control over the airplane. In direct law, some manual/mechanical backup systems are actually used.
If all FBW systems fail, there are limited mechanical backups to the rudder and elevators.
Sourse: http://www.airbusdriver.net/airbus_fltlaws.htm [airbusdriver.net]
Re:On top of that (Score:4, Funny)
What happened to your dad's foot?
Re: 25 knot window... (Score:4, Insightful)
So.... are we saying that a human pilot should be allowed to fly a plane in a 25 knot window?
I hope not.
Let's not forget ... (Score:5, Insightful)
It was a "battle hardened" human who flew the 'plane into the middle of a massive thundercloud in the first place.
Re:Irresponsible headline, summary (Score:4, Funny)
Gosh, that was such a terribly worded article summary I can't decide if the author is a regular 'editor' of /. or just a typical reflection of the poor taste and low competence of the /. editors.
Dunno, but the editor was kdawson. :-D
99% of the audience is unqualified (Score:5, Informative)
More accurately, there are very few people on Slashdot who have any fracking clue how a fly-by-wire system works. It's evident from the comments; just like everything else, people go spouting off and making claims about what they think things are like based on just a tiny bit of knowledge and their own prejudices, rather than looking at the facts and finding out what things actually are.
(Full disclosure: My day job is developing and testing a new FBW system, and I took an entire course dedicated to this in college.)
FBW systems are not the autopilot. They are not autonomous AIs, they do not make their own decisions, they do not just arbitrarily "decide" to go do something against the pilots' wishes. FBW systems are, in essence, little more than simple feedback control loops, similar to the familiar PDI controllers we all remember from control theory classes. All they do is compare the current state (pitch/yaw/roll angle and rate) with the one commanded through the stick, and try to make the two match by moving the control surfaces. The biggest difference is the presence of limiters which will prevent the aircraft from exceeding certain parameters (usually G load and angle of attack). That's it. That's all there is to a fly-by-wire system. It's just a controller.
In fact, let's compare a "traditional" manual system with a (simplified) FBW one from the pilot's perspective. In a traditional system, the stick/yoke in the cockpit is directly mechanically connected to the control surfaces through pushrods, bellcranks, cables, pulleys, etc. A given deflection of the stick will always result in the same deflection of the surface. For our purposes, we'll assume it's roughly linear, so Dsurface = K * Dstick. Now, let's look at the airplane as a whole. A given deflection of a control surface will not always achieve the same result--at low speeds, you need more deflection for a given response than you do at high speed. The net effect is that, at low speeds, the pilot needs to make large deflections of the stick make a given maneuver. At high speeds, he only needs to move the stick a little bit. It's kind of like your car--the steering gets more sensitive the faster you go; you wouldn't use the same inputs on the freeway as you do in a parking lot. Matching the desired response with the control input is the pilot's job--he's the feedback loop connecting control surfaces with the desired flight path.
A FBW system, on the other hand, doesn't have mechanical connections between stick and surface. Instead, the stick uses force or deflection sensors to read the pilot's input. That input is fed to the FCC, which then sends signals to the actuators on the control surfaces. Instead of commanding a given control surface deflection, the pilot's input will usually command something else, eg. roll rate or G load. Rather than varying according to speed and aircraft position, this will be constant--in other words, the command for 20 deg/sec will be the same at really low speeds as it will at high speeds. Basically, the pilot is telling the aircraft "do this", and the FCC figures out how to achieve that by moving the surfaces.
A FBW system will also often have limiters, which prevent the aircraft from exceeding certain parameters. Most common are angle-of-attack and G limiters. Angle of attack (AOA) is the relative angle of the aircraft to the oncoming air. Imagine sticking your hand out the window of your car, palm downwards. As you slowly rotate your hand so your palm faces forwards, notice that your hand wants to go up--you're making lift, and the angle of your palm to the airflow is your hand's AOA. Notice, though, that once you rotate too far, you stop generating lift--that's a stall. On a wing, the amount of lift generated is roughly linearly proportional to AOA, at least up to a point. Past that critical AOA, the air stops flowing smoothly over the top of the wing and gets all jumbled, causing a loss of lift. That's what a stall is.
Re:Irresponsible headline, summary (Score:4, Interesting)
That's pretty much what Boeing has done. The computers can fly the planes all day long. When something isn't right, the pilot can override the system simply by flying the plane like normal.
Now with the terrain following radar, this isn't a situation a pilot would be wanting to override the computer on. well, unless the plane nose dives and the computer proves/indicates it is unreliable. Then you have a choice, let the computer crash you or let the pilot attempt to not crash you. Only with Boeing is that possible, with airbus, regardless of the situation, the computer takes precedence.
A well trained pilot would know when to trust the computers and when not to. They would also know how to maneuver and react in situations. It's like the pilot that landed his plane in the river after losing an engine to birds. I don't think a computer would have taken that option and not only would it have been likely that all the passengers would have been killed, but bystanders as the planes computer attempted to correct and eventually goes down in a populated street.
Re:Irresponsible headline, summary (Score:5, Insightful)
well, unless the plane nose dives and the computer proves/indicates it is unreliable.
Good point. Disclaimer: I am a former Air Force avionics tech, F-15 TISS. Military fighters and civillian airliners are different beasts but I understand that the F-15 had a quad-redundant (trivia: the transporters in Star Trek: TNG have quad-redundant buffers) flight control computer.
Google searches reveal that Airbus' flight control computers are pentuple-redundant (two primary and three secondary flight control computers).
Another factor to take into consideration is that not all airline pilots are experienced. I don't like to dichotomize (like the poor summary of the article, dammit KDawson) but a pilot's first storm could bring hardening experience or crushing defeat.
Re:Irresponsible headline, summary (Score:5, Informative)
It's like the pilot that landed his plane in the river after losing an engine to birds. I don't think a computer would have taken that option and not only would it have been likely that all the passengers would have been killed, but bystanders as the planes computer attempted to correct and eventually goes down in a populated street.
For the record, it was an Airbus A320 (a full FBW aircraft) that was flown into the Hudson [wikipedia.org].
Stop trolling (Score:5, Informative)
the simple fact is we think this particular French Airbus crashed do to design failure, specificity computer related and not human failure and this only strengthens the case for humans to still be able to fully operate complex machines.
The autopilot disengaged at 23:10, 4 minutes before the last automated messages indicating failing cabin pressure were sent by the plane.
Re:Irresponsible headline, summary (Score:5, Insightful)
I would argue that "simple fact". IMHO any pilot who decides to fly directly into a large thunderstorm when going over it is a viable alternative has already committed pilot error, the computer probably let him fly further before crashing than he would have solo.
I would rather trust my life to a computer whose bugs can be ironed out and which will always perform the same way in a situation than a pilot who may or may not have gotten enough sleep, be drunk, or somehow be distracted. I've seen enough car crashes to know that humans are not the godlike infallible beings that the anti-computer controlled planes group seems to be preaching. Pilot error was blamed for almost 80% of crashes in '04...why would you want to trust your life to something that statistics alone dictate to be more likely to crash?
Re:Irresponsible headline, summary (Score:4, Insightful)
>"When something isn't right..." ...that part being "stabilizing controls damaged", followed three minutes later by "system that monitors speed, altitude and direction, main flight computer and wing spoilers all failed". And ... for some reason neither the pilot nor the co-pilot managed to send a radio message during that time.
ref [yahoo.com]
Yep. I reckon an American pilot in a Boeing could have just flipped a switch and fixed all that. They'd all be relaxing with cold ones as we speak.
Re:Irresponsible headline, summary (Score:4, Insightful)
>"we don't know if the Brazilian crash has anything to do with this."
Well, looking at the automated messages sent by the computer (nb. we didn't hear anything from either the 'infallible' pilot or copilot) I'd say it was damage to the plane, not computer error.
>I'd like to see a computer know to, and successfully land in the Hudson though!
Computers don't take decisions on *where* to fly, only how to set the controls. It was a human who flew into the middle of a giant thundercloud, not a computer.
And, errrr the Hudson landing thing was done in an Airbus. Somehow the pilot managed to steer and land an Airbus with no engines even though the computers were fighting him and obstructing his every move.
Or maybe they weren't.
Re:Irresponsible headline, summary (Score:4, Funny)
And, errrr the Hudson landing thing was done in an Airbus. Somehow the pilot managed to steer and land an Airbus with no engines even though the computers were fighting him and obstructing his every move.
Yeah, but if it had been a Boeing, the landing would have been smooth, and he would have reached port on his own.
Re:Irresponsible headline, summary (Score:5, Interesting)
In other fields such as medical diagnosis, allowing doctors to override the algorithm has been shown to decrease overall accuracy. Sure, sometimes they override a computer mistake, but more often they override the truth with their own mistakes: (cite [74.125.155.132])
Re:Irresponsible headline, summary (Score:5, Informative)
"Only with Boeing is that possible, with airbus, regardless of the situation, the computer takes precedence."
"It's like the pilot that landed his plane in the river after losing an engine to birds."
In that instance, the plane WAS an Airbus. The summary saying that Airbus doesn't have control overrides is imply lying. It's not true. All Airbus aircraft allows pilots to override computer control. You're right though, if that flight HAD been controlled by computer, then it would have crashed - not because of computer error but because it's simply not possible to plan that scenario. Even if you could program a computer to look for water landings in such an instance, and give it detailed waterway charts, it couldn't know if there was a ferry there or not, possibly killing everyone on board AND everyone on the ferry. Its simply impossible to allow for all scenarios. This is where having the option of human override is good - and thats why all planes allow it.
However, if computers had control, then many other flights which have crashed killing all on board would have been avoided. Plane crashes are virtually always either a) mechanical error or damage (such as the Hudson landing), b) weather/micro-burst related (such as Air France), or c) pilot error - either making the wrong decision, misinterpreting the information the computer was giving them, or blatantly ignoring the advice of the computer and resulting in a plane crash. There are very few incidents (if any) where computer control of an aircraft has led to its crash.
You seem to have bought into the summary, thinking that Airbus planes don't allow manual control. I assure you, thats not the case, as seen in the Airbus A320 on the Hudson River landing. It is unfortunate though, that in computer vs human scenarios, the vast majority of the time humans make the mistakes, not the computers. As discussed in many places here the Buffalo flight where the computer started diving and the human overrode it - people will say he's an idiot but the fact is the pilots flying all planes are just as capable of making similar mistakes, no matter how good their training. Computers can't make such a mistake, unless programmed incorrectly.
Re:Irresponsible headline, summary (Score:5, Insightful)
A well trained pilot would know when to trust the computers and when not to. They would also know how to maneuver and react in situations. It's like the pilot that landed his plane in the river after losing an engine to birds. I don't think a computer would have taken that option and not only would it have been likely that all the passengers would have been killed, but bystanders as the planes computer attempted to correct and eventually goes down in a populated street.
This comment looks sensible on the face of it, but I have to disagree with you. I have a pilot license and am familiar with the process of flying. I've never flown a fly-by-wire aircraft, but I've automated a radio broadcast desk - which might not look like it's relevant, but it taught me that "knowing when to trust the computer" is not an obvious state, not in a radio station and I seriously doubt in a cockpit.
For me the final "aha moment" came when the computer was attempting to tell me something useful, but because I was concentrating on a completely different aspect of interacting with it, I completely missed the information. In my case it caused a few seconds of dead air on a radio station, nothing life threatening, but not human obvious either.
The challenge is not "when to trust a computer and when not to" - the challenge is "how do you get the information that the computer is using to the human in such a way that they can manage that input stream in a timely fashion. Stick shakers are an example of making use of an extra input channel.
Accidents in planes are rarely just one thing going wrong, they generally are a whole string of things. A computer in the mix just exacerbates the issue.
Re:Irresponsible headline, summary (Score:5, Insightful)
Every time I see a Wikipedia article flagged for containing "weasel words" I think "God, give me a break, even 'weasel word' is a weasel word", but this summary should be held up as a shining example to all of exactly what a weasel word is and how much they can slant the entire tone.
Re:Irresponsible headline, summary (Score:5, Informative)
Airbus autoflight is not the demon that Boeing and the press would like you to believe. They keep rehashing old shit like the Habsheim Chainsaw and reiterating the same tired talking points without considering that the software is vastly superior now than it was in 1988. In any event, THE SYSTEM WILL NOT FIGHT THE PILOTS.
Let me restate that again, just in case you missed it - THE SYSTEM WILL NOT FIGHT THE PILOTS. The system just gives me the best the airplane can do at the moment without me having to stop and consider my conditions.
If I as the pilot deflect the stick left, if the autopilot is engaged, it will be disengaged for me. The load factor is considered and the airplane will begin a maximum-rate roll in the direction I deflected the stick. I keep holding the stick and the airplane will keep rolling up to the limiter. That's when Normal Law is active. If we're in Alternate or Direct law, there is no roll limit and I can roll the airplane onto its back and crash it if I desire.
The same thing applies to hauling the stick back. If I haul the stick back, I get maximum-rate climb, and if I forget to push the throttles the computer will do that for me too when I hit alpha floor. That means instead of trying to fly the airplane and avoid the other airplane or granite cloud or whatever it was outside that I am trying to not hit, I can just concentrate on avoiding the whatever and the airplane will manage everything else.
I never have to "disengage the computer" to get the airplane to do something. I just move the controls and the airplane follows. If I recenter my controls the airplane will DO WHATEVER *I* ORDERED LAST. It -WILL NOT- go back to whatever it was doing before until I tell it that it can do that.
Let's say I get a TCAS. The offending traffic is dead ahead and I can't see him. All I do is haul the stick back (or shove it forward depending on the TCAS instructions) and then INSTEAD OF LOOKING INSIDE THE AIRPLANE AT MY SPEED/THRUST SETTING/ETC, I can direct my attention OUTSIDE OF THE AIRCRAFT TO SEARCH FOR THE CONFLICTING TRAFFIC. This will give me a far better chance to determine whether or not the other guy is doing what TCAS told HIM to do and avoid him if necessary than if I have to divide my attention between the airplane and outside. The airplane will kill the thrust or whatever it needs to do to avoid overspeed. The other pilot can be looking outside as well, so we have two sets of eyes looking for (and ideally seeing) the other airplane and working to avoid him.
Now, when shit hits the fan and things break - Airbus has MULTIPLE REDUNDANT SYSTEMS that continually cross-check each other as the flight goes on. If there is a discrepancy in data, the affected system IS DISABLED. The airplane will NEVER follow erroneous sensor data unless it sees the SAME ERRONEOUS DATA on BOTH SIDES SIMULTANEOUSLY, *AND* THAT ERRONEOUS DATA MATCHES HEURISTICS.
When certain important systems fail the computer WILL NOT simply use the other computer since it now has no means to cross-check it. What I get instead is a CONTROL LAW REVERSION. That is, the airplane takes the protection logic OUT OF THE LOOP ENTIRELY, since it can't provide protection with faulty data. There are three layers of reversion until you get to DIRECT LAW, which is "737 Mode". The system reverts automatically in response to the data it sees.
Re:Irresponsible headline, summary (Score:5, Funny)
Re:Irresponsible headline, summary (Score:4, Insightful)
It fails #1 because in Normal Law there is no protection against allowing the airplane to fly into the ground. The computer knows its height above terrain (radar altimeter) and will provide warnings, but it won't stop descending. Of course, they could patch that in...
There is also the case of allowing the aircraft to run out of fuel. Maybe program it to find the nearest suitable airport and set up an autoland? This would be an interesting experiment.
That's just off the top of my head. Laws two and three are fine since the computer won't generate commands of its own accord anyway (the humans DID input the flight plan and FMS parameters, after all) and doesn't have weapons with which to kill people, but the "inaction" part of rule 1 is a bear.
Re:Irresponsible headline, summary (Score:4, Insightful)
The pilot must always have the option of manual override. *PERIOD*
Well, that depends. Do the humans or the computers have a proven history of fucking up more often?
Sure, the computer could malfunction. But how frequent is this compared to situations where it does something unexpected and the pilot thinks it's malfunctioning when it actually isn't, and that "something unexpected" is actually needed to keep the plane in the air?
Re: (Score:3, Insightful)
When you then put those human-designed systems in complete control, you risk the hidden design flaws and software logic errors coming out to play at some of the most inopportune times - basically bounds testing but with real human lives in the balance.
Re: (Score:3, Interesting)
My step-brother is a commercial pilot (mostly small hop, but working his way up to big jets), he never was a military pilot (though he was military), but he also didn't hop into piloting a jet straight from a sim either. He had to have a huge amount of actual flight hours before they even let him into a cockpit of a commercial jet. And another largish number of hours before they'd let him co-pilot. Etc..
People flying large passenger jets are skilled and experienced, military or not.
Actually, when everyon
Re:Irresponsible headline, summary (Score:5, Informative)
He was given the adulation because water landings are notoriously difficult to pull off, with the number of successful ditches so low that the procedures are still essentially educated guesswork. A random swell that catches a wingtip or engine nacelle can cause a plane to flip or to break open. Hit too steeply -- something that again can change with a swell -- and the plane may decelerate fast enough that injuries or death occur.
All planes come with a checklist for ditching in the water. Few pilots come away from actually using them unscathed.
Re:Irresponsible headline, summary (Score:5, Interesting)
Re:Irresponsible headline, summary (Score:4, Funny)
Re:Irresponsible headline, summary (Score:5, Funny)
Next up: how this crash is actually the fault of RIAA and Airbus should have used Linux.
Wow. I've been reading Slashdot long enough that I know exactly what arguments could be made to advance those two statements.
Re:Irresponsible headline, summary (Score:5, Informative)
Yes, it is an annoying debate tactic [wikipedia.org] but weak and relatively easy to recognize. Diligent readers can recognize this though, and the glaring errors often come painfully to light in the discussions.
Anyway, the Airbus systems have multiple levels of computer massaging of the pilot's input, called different "flight laws." Read up about it here:
Airbus flight laws [airbusdriver.net]
In the most direct law, yes, the system will still not allow you to do things like rip the rudder off the airplane [wikipedia.org] (A300 was not FBW) or clearly overstress the aircraft and destroy the wings. This is a good thing -- of course, there is perhaps some imaginary situation where it would be better to destroy the aircraft to ameliorate some aspect of an impending crash, however, the vast majority (all ever recorded in an actual crash?) of inputs that can destroy aircraft are not intentional nor required. Also, the 'direct law' will allow a pilot to potentially overstress the aircraft in the event of computer failure or discordant input.
The role of conflicting pilot input is also well thought out (described in the link), and the airbus designers were aware of these (pseudo)philosophical objections to excessive computer control. I do not think there is much of a conflict among people familiar with the operation and implementation.
Re: (Score:3, Insightful)
>I do not think there is much of a conflict among people familiar with the operation and implementation.
Yes, but this is slashdot where kiddies quote Ayn Rand and Ron Paul for instant +5 insightful and quote generalizations about Americans vs Europeans which would make the worst 80s hack comedian blush. Sadly, there's probably a good thread to be made about computer controls in avionics, but instead we get flamebait from the slashdot editors at the get go.
Re: (Score:3, Interesting)
Re:Irresponsible headline, summary (Score:5, Funny)
This is the danger of communism. Obviously, on a Boeing, Tom Cruise would have guided the plane to safety with PURE AMERICAN FREEDOM(TM).
Oh fuck off.
And (Score:3, Funny)
Re:Irresponsible headline, summary (Score:4, Informative)
Huh. Funny that the Wikipedia article on Fuel dumping [wikipedia.org] even shows a picture of a "Fuel dumping point of an Airbus A340-311"...
Here's another quote from that article:
"Longer-range twin jets such as the Boeing 767 and 777 and the Airbus A300, A310, and A330 may or may not have fuel dump systems, depending upon how the aircraft was ordered, since on some aircraft they are a customer option. Three- and four-engine jets like the Lockheed L-1011, McDonnell Douglas DC-10 / MD-11, Boeing 747 and Airbus A340 usually have difficulty meeting the requirements of FAR 25.119 near maximum structural takeoff weight, so most of those have jettison systems. A Boeing 757 has no fuel dump capability as its maximum landing weight is similar to the maximum take-off weight."
Get your facts straight, Mr. Boeing-Name-Tag.
Re:Irresponsible headline, summary (Score:5, Insightful)
And remember that the recent plane crash in NY was caused by human error: the autopilot responded to the ice buildup by diving to maintain speed, the pilot 'corrected' what he though was an error and the plane fell to the ground like a stone.
The truth is, modern computers can be much much better pilots than 95% of the pilots out there. I don't think the autopilot would have even attempted the landing in the Hudson river, here the pilot was clearly one of the top pilots that I want on every single I fly. Also I'm pretty sure that good pilot was not overworked and was well rested before his flight. Whatever good training you have humans will always make mistakes and they get worse with fatigue. The computer does not get tired, or emotional.
So with an average pilot, I think the autopilot is much more trustable. In case of exceptional emergency, a true outstanding pilot might pull it off where the computer will not. I'm not sure the data (if it exists) favor the humans though.
Re:Irresponsible headline, summary (Score:5, Interesting)
From everything I've read the landing in the hudson seems like a fluke. Apparently landing in water is far more dangerous than landing on land. Granted, with lots of buildings all around him I'm not sure the pilot had a lot of options.
I did take some exception to the term "battle-hardened" - a fair percentage of pilots who go through serious air emergencies end up dead, and since so few emergencies happen few pilots are experienced with them. On the other hand, the flight computer has the experience of every simulated and real emergency any plane has ever been through. Sure, humans can practice in the simulator as well, but the reality is that costs mean that no individual gets that much time in the simulator. Due to the magic of software when one flight computer knows how to handle some situation, they all do.
I suspect the Boeing design reflects the American legal system. If the plane goes down and it is the pilot's fault, you can sue the pilot. Maybe you can even sue the airline who trained him. On the other hand, if the plane goes down and the pilot had no control then you can sue the aircraft manufacturer. Never mind that the design saves lives - better to allow thousands to die at somebody else's hands than one to die at your own. Gotta love the tort system.
For the same reason we'll allow tens of thousands to die every year in auto accidents due to driver error but we'd never consider automating driving because maybe somebody might die every year or two due to a computer error.
Re:Irresponsible headline, summary (Score:5, Insightful)
On the other hand, the flight computer has the experience of every simulated and real emergency any plane has ever been through. Sure, humans can practice in the simulator as well, but the reality is that costs mean that no individual gets that much time in the simulator
What utter nonsense! All the computer has is a set of heuristics derived from various situations that have been selected by its human programmers to represent the set of scenarios likely to be encountered. The heuristics aren't perfect. The choices made by the programmers aren't perfect. The computer has no magic database of all accidents that you describe. How the FUCK does this lame bullshit get modded up?
Due to the magic of software when one flight computer knows how to handle some situation, they all do.
Are you even paying attention to what you're typing? You're trying to be clever by using the term "magic" to encompass all the knowledge the computers encapsulate, but you've done so in such a way that it makes you sound like a fool who believes there's literally something magical about the software.
Computers can ONLY do what they're programmed to do. If the situation encountered is not one that was planned for and tested, the computer can make stupid nonsensical judgements that no human of sound mind would ever contemplate making. There's no sophisticated AI flying the computer that understands the context of the flight (even if there are "AI" components in the flight programming).
Re:Irresponsible headline, summary (Score:5, Insightful)
Bloggers need to say stupid shit like that in order to drive traffic via provocation. kdawson, you should be ashamed of yourself for posting this tripe.
Re:Irresponsible headline, summary (Score:4, Interesting)
Agreed. Second paragraph: "It's been well established that Air France Flight 447 went down because on-board computers received conflicting information from sensors on the outside of the plane." Does this come from CNN or the wild speculation on airliners.net? It certainly doesn't come from accident investigators, who really have no idea yet what happened. What was cause and what was effect has not been at all established.
As to the point: Airbus does have alternate laws and direct law, when situations warrant it. Basically the logic, reading the technical briefs linked off airliners.net, is that if the computer isn't sure what's going on, it puts up big warning signs telling the pilot they're in control. Depending on what sensors and information is missing or contradictory, different protections get disabled, with corresponding indicators displaying warnings. It wouldn't surprise me if there wasn't a way to override the systems in the first place and place the plane into alternate or direct laws. The author quotes no technical documentation whatsoever and just says "Boeing" and "Airbus" which is a ridiculously broad brush.
The blogger is, in short, presenting wild speculation and misleading generalizations as fact, and rewarded by the /. community with healthy ad revenue and page views.
Re:Irresponsible headline, summary (Score:5, Insightful)
I'm sorry, I didn't think TFS actually presented one side as better than the other. Maybe it's because I work in aerospace and take more things as given than you, but to me tfs raised a very interesting philosophical question. The summary even says that it's not a design flaw- it's a philosophical divide.
I know several people who HATE flying because- even though they understand intellectually that flying is much safer than driving- the idea of falling to earth, out of control, with many seconds or even minutes to be aware of the terrible situation is much worse than feeling able to control their path in a car.
I myself feel like I've outgrown that feeling. I've literally entrusted my life to other people so many times that when I get on a plane the idea of dying or crashing doesn't even cross my mind. It is a conscious flipping of a mental switch: I am not in control. This plane is being flown by someone who also does not want to die and that person knows what they're doing.
And on the other hand I've read enough after-action briefs of computer glitches crashing planes that I don't entirely trust computers to fly. Yes, they have faster response times, yes they can look out for the airplane better than a human. Usually. Usually, they can do those things better than a human. Why WOULDN'T you allow a human into that chain of control? If the computer is going nose down into a mountain because of a frozen AOA probe, the pilot should just sit there and start praying? If the computer starts shutting down engines because of faulty fuel indicators, the pilot should just sit back and say, "Hey, we took off 45 minutes ago with 5000 gallons of fuel and barring an open fuel cap, there's no way we're actually out, but whatever, I'll accept a cold death in the north atlantic if it saves the engines from a potential flameout"?
Here's where I sit: Computers should fly planes. Humans should solve problems. Computers are not perfect; if they were, we wouldn't need IT or pilots or astronauts or mathematicians. Someday when AI is improved and flight control computers absolutely do not cause stupid accidents, then I'll allow and empty cockpit.
What I propose is a compromise, just like the american company, and it has nothing to do with john wayne or ayn rand or any other stupid emotionally-weighted crap.
Hi, my name is ben, and it's my job to keep people from dying in airplanes, and I'm in favor of pilot intervention to avert crisis.
Any typos were the computer's fault ;)
-b
Not irresponsible but wrong (Score:4, Insightful)
However the snippet is wrong in that it is extremely surprising given the comparison between US and European cars where the situation is completely reversed. Drive a US car and the damn thing won't let you start the engine without a manual having to have BOTH the clutch depressed AND be in neutral which is plain stupid since either is sufficient and I usually just depressed the clutch to start the engine. Not to mention the number of times the stupid thing pings at you: put your keys in the ignition without turning on the engine *PING, PING, PING*, turn off the engine but down't take your keys out fast enough *PING, PING, PING*, put some luggage on the passenger seat *PING, PING, PING* (no seatbelt!), driver not yet irritated enough *PING, PING, PING*. Of course it also pings at you if you leave your lights on, which is useful, but by this time most people have reached under the dashboard and forcibly removed the device which goes *PING* in order to retain their sanity. This makes it about as useful as those stupid dialogue boxes that ask you "Are you sure you want to do that?".
So given this experience I am extremely surprised that it is the opposite way around with aeroplanes.
Re: (Score:3, Funny)
it is clear to me that the Air France crash was caused by icicles forming on the propellors, making them get stuck.
You forgot one thing. The pilot's bible states that before the pilot puts the plane into a steep nosedive they should send a co-pilot or flight attendant out on the wing to try to spin the propellers themselves to break the ice.
Nosediving should only be done as a last resort.
Troll detection sensor failure (Score:5, Funny)
You are clueless and do not belong in a cockpit (not that I believe for a second that you actually are a pilot)
That 'whoosh' you hear is the failure of the parent poster's troll detection system. The troll detection system maintains level posting attitude for turbulent articles. CmdrTaco speculates that a similar troll sensor failure resulted in catastrophic Karma loss that may have contributed to the crash of Flight 447. Slashdot recommends that future posters be immediately retrofitted with properly functioning troll sensors.
Re: (Score:3, Funny)
Re:Irresponsible headline, summary (Score:4, Interesting)
you can thank all the shitty pilots in the US airways on the breaking of the pilots union.
that union had some STANDARDS for who they would let fly.
What the heck is 'battle tested' supposed to mean? (Score:5, Insightful)
What a dumb phrase. Do you only want former airforce pilots who've actually seen combat flying commercial planes? How exactly is that going to keep you up in the air in a civilian airliner experiencing an electronic or mechanical malfunction?
And if what you really mean is experienced pilots, what about some pilot who's been flying for years and has never had an emergency situation and then makes a mistake and then (s)he makes a judgement error in a critical situation? Are you then going to call for the iron calm of a computer rather than a fallible human pilot?
No, the answer is statistics. What's safer and more reliable in the long run? How many crashes have we had due to computer error rather than human error given x hours flown by each?
The very wording of this ridiculous post presupposes an answer. And in the future it is very likely the wrong answer. Sure computers will make errors. But in general people will make them more often, and computers are just going to get better.
And casting this as some kind of bizarre collectivist vs. individualist ideology debate is ridiculous as well. What does towing some ideological line have to do with safely getting to your destination in an airplane?
This Slashdot article is full of simplistic drivel designed to provoke ideologically based knee-jerk responses instead of any kind of reasoned debate.
The linked to text is much, much better, even though offering people a choice is problematic given how the whole non-refundable ticket system and airline logistics systems currently work, not to mention that making a choice at the gate when you get on the plane will throw off your schedule.
Re:What the heck is 'battle tested' supposed to me (Score:5, Funny)
What a dumb phrase. Do you only want former airforce pilots who've actually seen combat flying commercial planes?.
Who wouldnt want to be on a commercial flight where random barrel rolls, climbs and dives occur?
Re:What the heck is 'battle tested' supposed to me (Score:5, Interesting)
It was really something, a view like you would not believe, and if we had not been doing our figure-8s over something that impressive, I would have been really pissed, because my tummy was also doing figure-8s.
Re:What the heck is 'battle tested' supposed to me (Score:5, Interesting)
i read somewhere about a pilot flying an empty cargo plane (large-size jet, iirc) back who put it through a vertical loop (vomit-comet style) just for fun. seriously annoyed the company, as it knocked a few thousand hours off the lifespan of the plane.
Pilots in the airforce do this kind of stuff all the time. My colonel once had a fighter try to steal his landing approach when he was flying an empty cargo plane. Empty those things have tons of lift, so he threw the plane on its side and outturned the fighter to make the landing.
And like those scenes in Top Gun:
When my dad was in Thailand during the Vietnam War, they got a new general in at Kurat AFB, and marshalled the whole base for this formal ceremony. Right in the middle of it, an F-4 pilot buzzed the crowd at a very low altitude (the general on the stage hit the deck). Nobody could figure out who did it ("oh, sorry sir, all the planes were in the hangar that day"), so the guy was never caught. But then again, they didn't try very hard either, since that's the culture in the Air Force.
Re: (Score:3, Interesting)
No, the answer is statistics. What's safer and more reliable in the long run? How many crashes have we had due to computer error rather than human error given x hours flown by each?
Statistics is only the answer if it measures the right thing. At a minimum your suggestion doesn't qualify because computers fly planes on autopilot almost all of the time anyway. Sure there are better statistics to be looking at, I can think of a few myself off the cuff, but better than junk doesn't mean good or useful.
So beware the fallacy that we do know the answer, it may ultimately be that we are simply incapable of measuring the correct variables to make a mathematically sound evaluation.
Re: (Score:3, Insightful)
"Battle tested" may have been used in this context to refer to the long history of human pilots compared to the shorter history of using computers to control aircraft. If it refers to actual combat flight, flying military aircraft teaches one to expect something to br
Re: (Score:3, Informative)
I come from a family of pilots (IANAP), and they all live quite well. The low pay is a known problem, because many pilots do extra duty to make ends meet, but it also has the effect of encouraging only the truly motivated ones to stick around.
Hrmm (Score:5, Funny)
"What are you doing Dave?"
Philosophical Divide (Score:4, Insightful)
Lemme' guess... you're an American.
You only want humans to override the controls (Score:3, Funny)
Pick your poison (Score:5, Insightful)
The Continental flight that crashed in Buffalo on the 12th of February crashed because the inexperienced pilot pulled up when the plane stalled. A computer controlled system might have nosed down to get airspeed and saved 50 lives. Of course I doubt a computer controlled system would be able to make a flawless landing in the Hudson.
Re:Pick your poison (Score:5, Insightful)
I doubt a computer controlled system would be able to make a flawless landing in the Hudson.
Quite so, but your average pilot couldnt either.
Sully was a very experienced glider pilot( Including a CFI instrutor rating, as was the captain of the Gimli glider.
When the engines stop, just hope the pilot is experienced in flying without power
Re: (Score:3, Interesting)
Compare the numbers... (Score:3, Interesting)
...of crashes due to computer error and pilot errors in crashes covered in episodes of Air Crash Investigations (Mayday).
http://en.wikipedia.org/wiki/List_of_Mayday_episodes [wikipedia.org]
Hint: There were no crashes due to computer error.
Experience (Score:3, Insightful)
Re: (Score:3, Insightful)
That's all well and good, but engineers aren't gods. They can't anticipate everything, nor can they design systems that are full proof (AirFrance 447
This isn't a political decision (Score:5, Insightful)
It's not surprising that an American company errs on the side of individual freedom...
Eh? You mean the freedom to work under-paid pilots 14-16 hours a day like Colgan Air? And the FAA let them slide because Colgan had friends in that office? Some of their pilots could make more flipping burgers. Like the pair that were tired, under-paid and not paying attention who turned Continential flight 3407 into a giant lawn dart.
This isn't political. I don't care if it's human, machine or a trained goat. Whatever gets the aircraft down in one piece is what I want managing the control surfaces.
The article is a load of rubbish... (Score:5, Insightful)
American Aircraft don't always have manual overrides, and EU (UK, German, French) aircraft often don't lack it. In fact Airbus is its own company and as such follows its own principles as far as design goes. Right now they're designing their aircraft to be as simple as possible and want to eliminate a lot of the human element.
I don't agree with a lot of the discussions Airbus has made over the years:
- Low strength materials in key areas
- No warning alarm when auto-pilot is disengaged
- Less manual control in case of system failure
But then again Boeing has made some HUGE errors and has updated their 747 thousands of times to fix design flaws. People forget that not only is Boeing an older company but a lot of their aircraft designs are up to 40 years old and have been evolving constantly.
American Vs. EU is complete bs but whatever helps Americans sleep at night.
over-simplistic FUD (Score:3, Insightful)
First, I would say it naive to think that computers are somehow at fault, and that they do not have a net benefit. The main reason to use digital solid state computers is that they often reduce discrete component count, which usually increases reliability. In a system that is supposed to nearly 100% reliability, like an aircraft, component count must be kept to a minimum. That has traditionally mean fly by wire, and the more fly by wire, the better. My understanding is that Airbus reduces complexity significantly assuming a complete fly by wire profile. One could, for instance, install backup hydraulics, which I assume is not done, but this would reduce reliability.
There is not simple solution. Things do not increase security and reliability simply because we feel better. For instance, Many people feel safer in big trucks but many studies have shown that one is safer in a full size sedan. Likewise, one thing that makes a large truck, especially an SUV safe is the electronic stability control, which can countermand any driver instruction. Large planes are already computer controlled. Long haul flying of large planes is in no way a trivial task. I agree with the blog mentioned in the article that people who have no experience have no basis to make any useful comment.
Is summary accurate? (Score:5, Informative)
Summary states:
Boeing planes allow pilots to take over from computers during emergency situations, Airbus planes do not.
According to this link [airbusdriver.net], the Airbus does, in fact, have a manual override mode.
Which would make the argument as presented a moot point.
Re:Is summary accurate? (Score:5, Informative)
That is completely true - the computer in the Airbus can not override the pilot. After the computers overrode the pilot's input at the Paris Air Show, causing the airplane to crash, Airbus added a mode called "direct law" that allows the pilot absolute control over the aircraft. There are several different flight control laws, depending on which of the three redundant flight computers are in operation, and in what mode:
Normal Law - computer prevents pilot from excessive pitch or bank, excessive speed, stall from insufficient speed, excessive load factor, and augments yaw (rudder) control.
Alternate Law - Aids in low and high speed stability, and excessive load factor, as well as yaw damping.
Abnormal Alternate Law - yaw damping and excessive load factor protection only
Direct Law - No protection, pilot can do anything they want
Disclaimer: I am a commercial pilot, but I am not an Airbus pilot. I have studied Airbus systems, and have about 10 hours of A320 (full motion) simulator time.
Re:Is summary accurate? (Score:5, Informative)
In order to get to the manual override mode in an Airbus (IIRC) you have to navigate through several screens on the flight control computer and disable everything via menus. In order to activate the manual override mode on a Boeing plane you just have to move the yoke. In an emergency situation where, for whatever reason, the automated flight controls aren't working or are working improperly the Boeing override implementation is vastly superior to that of the Airbus. Not to say that autopilots and fly-by-wire systems aren't useful, but they aren't infoulable and limiting the pilot's ability to respond to a situation just seems like a really bad idea.
I won't fly with a "Battle Hardened" pilot. (Score:3, Insightful)
Generally airlines stopped hiring ex-military pilots as they tend to crash too often killing hundreds of people at a time.
Military pilots find it hard to change from "Achieve objective; fly hard and kill bad guys" to "Land passengers safely at all costs" mentality.
A huge oversimplification to say that US maker Boeing provides the freedom for pilots to fly. By the same token, you might well say that The US is the most over-regulated country on the planet, so why are pilots allowed to fly it with such freedom?
I think that in general, you are arguably better off when the pilots are connected to the flight surfaces via manual controls. Even if the power and hydraulics go out with enough strength you may move some control surfaces a little - perhaps enough to control a plane in level flight - maybe even land it.
But if FBW shits itself - you are TOAST.
And for every crash caused by pilots not being able to take the control of a plane, there's probably another crash averted by the computer.
The biggest problem of course is that flying a wide-bodied jet is 99.9999999% pure boredom followed by 0.0000000001% when you live or die because of a series of bad circumstances piling on top of each other.
If the hardware fails for any reason (pilots get wrong information) then they can't expect to live for long - especially if the computers are flying it. At least if sensors start failing, humans are flexible enough to know something is wrong, and work around it.
In general, I would prefer to be flying on a wide bodied jet that has the computer fly the entire flight, but with a pilot on board who is exceptionally good at looking at the computer non-stop to decide if it is working right. I expect that pilot to be so good, that he understands the point at which he needs to kick the auto-pilot into touch, and take control of the plane.
See my signature. It's standard, not put here for this post.
Overrides for when computers go mad. (Score:5, Insightful)
As an ex airline pilot and current software developer I would say that an override must be available in any system. Of course computers are much better in quick decision making and collecting all the facts than humans are. In fact with a glass cockpit, the computer knows the data before the pilot does anyway. But there is the occasion that software fucks up. Plain and simple.
From my own personal experience:
1 - Autopilot with suicide attempt
Boeing 737-400 cruising at FL310 everything happy, clear skies. I'm Pilot flying and the captain suggest I have lunch. With the tray on my lap I eat while glancing at the instruments every once in a while. The captain was supposed to have control. So after a particular tasty piece of chicken I look up only to see the horizon at an angle and way too high. I glance across and see the captain reading the news paper. Look at the instruments which indicate a gentle diving turn. The VNav path on the displays indicate nothing out of the ordinary but this Autopilot decided to go for a turn and decent anyway. The whole thing would have only lasted a few seconds but there was absolutely no reason for the computer to do this manouvre. AP disconnect and reconnect sorted it all out.
2 - Lazy plane
Yeah, uh again during my mean and again I had handed control over to the captain while eating. This time at night. Cruising FL330 when auto throttle decides to close the throttles to idle. Auto pilot maintains altitude. WTF to I push the throttles back up. They stay up for a few seconds and yet again move to idle. Got rid of my food and disconnected the auto throttle. Set cruising power manually and checked everything. Nothing wrong. Re-engaged the auto throttle and things were fine.
3 - Dutch roll gone bad
Climbing through 10.000 feet on auto pilot, the plane begins a slight rocking left and right. No more than a few degrees. As we continue to climb the rocking gets worse. 5 deg bank either way. Auto pilot is working hard to compensate or so it seems because the control column moves noticeably. Again my luck to be pf. We thought the Autopilot had gone mad so after strapping ourselves in tightly we disconnected the ap. I tried to hand fly and stabilise but things got out of control rapidly as the plane started to buck left and right well past 10 degrees bank. I was obviously losing control. Nah, let's face it, I had no control and told the captain. He took over and at least was able to not allow it to get worse. Glad I was with this guy because he flicked off the yaw damper that is an automatic control system to stop an aerodynamic effect called Dutch roll. The plane steadied immediately although we were left with the Dutch roll effect but that was not too bad.
So there you go. In all three cases it was not a matter of pilots being better than computers. Overrides are required when the computer goes mad. I always valued having the mechanical controls as a backup in the 737. I travelled in Airbus aircraft and I no longer fly but I would still hesitate to be a servant to a fly by wire system.
Re:Overrides for when computers go mad. (Score:4, Insightful)
Hmm. Sounds like the real problem here is that autopilots are not built to explain their decisions? I mean, what if there was a reason for the auto-pilot to be doing those things that made sense, you just didn't know what they were? Wasn't one of the air disasters mentioned earlier in the discussion where the auto-pilot dived to maintain speed after there was ice on the plane, and the pilot overrode it because he didn't understand why?
something interesting about the airbus (Score:4, Interesting)
it's all electronic control, rather than hydraulic/ pneumatic controls. meaning its more simple, but it's also more rigid: if your computer goes, so goes your aircraft. yeah, they use triple redundant systems, but how many electric surges do you need to take out 3 computer systems in an aluminum tube?
learned from this interesting comment:
http://community.nytimes.com/article/comments/2009/06/02/world/europe/02plane.html?s=3 [nytimes.com]
Re:something interesting about the airbus (Score:4, Informative)
A very badly informed comment though - it's actually so wrong it isn't even wrong.
Boeing use both fly by wire and composites. The B777 is full fly by wire, just like the Airbus (The B777 is a great aircraft - very reliable, with no fatal crashes to date - only one has crashed - no one was seriously hurt - due to fuel contamination). The B787, which is Boeing's next model, is almost *entirely* composite - it's the first airliner to be primarily composite construction. It is due to enter service in 2010 (and has suffered some delays). Oh, and it's fly by wire too, naturally.
Composites are also much stronger than aluminium - it is no accident that high performance gliders have been made from composites since the 1970s - you can't make gliders with such a slender wing as something like any open class glider - huge long 25 meter plus wingspans, with very little chord - with aluminium. The best aluminium gliders were the designs by Richard Schreider in the late 1960s - he brought aluminium to its limits in the design of high performance gliders. Composites also have other advantages - you can make much more efficient shapes with them too.
Boeing vs. Airbus, not US vs. France (Score:5, Insightful)
Re:Boeing vs. Airbus, not US vs. France (Score:4, Informative)
That's a great article by William Langewiesche. Note that he makes the point that Flight 1549 was able to make a smooth engines-out landing in the Hudson because the flight control computers were helping all the way to the water. The computers kept the aircraft just above stall (which is very tough with no engine power) and allowed a slow descent and a slow landing speed (which are competing goals for an aircraft).
right now, nothing is well established (Score:5, Insightful)
Perhaps not the most diplomatic response, but it is true enough.
First, there is absolutely nothing conclusive to say about Air France 447 at this point other than it did indeed crash (thus ruling out alien abduction and time travel). There are no conclusions, or even anything that could really be called a theory, just guesses and hunches ranging from informed to wild-arsed. At this point, nobody can even be certain as to whether the mismatches in indicated airspeed happened before or after the aircraft started to break up. As WAG level example, if lightning had damaged the radome at the nose of the aircraft (has been known to happen), then the three pitot probes could report different velocities not because the probes failed, but rather because to aircraft no longer conforms to the aerodynamic profile the pitot probes are calibrated for.
Also, the difference between Boeing and Airbus is not as stark as the author would like to think. On both manufacturers' most recent aircraft, in normal flight the computers will automatically do a variety of nifty things (like auto-mixing the use aileron/rudder inputs, vertical gust load alleviation, etc, to increase efficiency and comfort) in ways entirely transparent to the crew. The differences are at the extreme limits of the flight control laws. There, if the pilots pull on the controls hard enough, a Boeing plane should accept the input even when the computer thinks the input will cause permanent, or even fatal, damage to the aircraft (it will warn the crew, loudly). An Airbus plane will limit the input so as to avoid such damage (and notify the crew it is doing so). There are legitimate arguments for both configurations, and America vs Europe has nothing to do with it (old dog vs new pup might, if you could go so far as to call Airbus a new pup). At the extreme limits it is not a matter of ingenuity versus information, but more of protecting what you have left right now (an unbroken airplane in danger of crashing), or allowing risks that might let you get to a better place (a damaged, but perhaps un-crashed (for now) airplane).
In either case, by the time a flight crew encounters the philosophical differences between Boeing's and Airbus' respective control laws, they are already frakked, and in a damned if you do, damned if you don't scenario.
In both cases, part of the flight computers programming is there to monitor itself, and its sensors, for failures that would compromise its function. In a situation where the airspeed indicators no longer agree with each other, the computer should automatically reduce any limiting role it has because the computers' input data is no longer reliable. And as current commercial airliners are reasonably stable in the aerodynamic sense, they can continue to fly even in the event of a total computer failure. Look carefully at cockpit pictures of the shiny new Airbus A380 and you will see a small cluster of old fashioned instruments amongst all the flat panel displays. The computer can fail, and of all the things on an airliner, the computer is the item most aware of this.
But which planes crash the most? (Score:5, Insightful)
From where I'm sitting, it seems boeings fall out the sky with more often and with more devastating results than Airbuses - http://news.bbc.co.uk/2/hi/in_depth/2008892.stm [bbc.co.uk]
I particularly liked when the A320 came down in the Hudson how, it was "all thanks to the pilot"...and yes, in part it was, but the minute another airbus falls out the sky and it's fatal this time (as crashes often are) it's clearly because of poor design philosophy?
Meh, this whole thing stinks of US vs EU chest-bashing.
Re:Give the pilot control! (Score:5, Informative)
"If the Gimli Glider or Flight 1549 had been on an Airbus, there would have been a lot of dead people"....
fyi- Flight 1549 was an Airbus A320. Perhaps you would like to rethink your conclusion?
Re: (Score:3, Insightful)
ummmm Flight 1549 was an Airbus 320.
1549 was an Airbus A320. Stop FUDing. (Score:3, Insightful)
If the Gimli Glider or Flight 1549 had been on an Airbus, there would have been a lot of dead people. When something goes wrong, Rule 1 is FLY THE FUCKING PLANE. Well, if the computers fail on an Airbus, good luck flying it!
Flight 1549 was an Airbus A320 [wikipedia.org]. Don't fall for the FUD, any large passenger airliner is going to be designed to be as survivable as possible in the event of power loss. This whole article is just another example of irrational hysteria.
Re:Give the pilot control! (Score:5, Insightful)
Boeing and Airbus have had roughly identical numbers of crashes in recent years. Boeing has had just a fraction more. If one method of flying was better than the other, there would be a difference, right? Since there is no measurable difference, it follows that the differences in a crisis balance out. What is good for one sort of crisis is a disaster in another.
Re:Human limits (Score:4, Informative)
Re: (Score:3, Insightful)
Crossing the street and driving a car are both 'decided risks" too. It's just that infrequent but large scale fatalities generate more paranoia and subsequently bigger headlines than daily individual fatalities.