Investigators Suspect Computers Doomed Air France Jet 403
DesScorp writes "Investigators working with the wreckage of Air France flight 447 believe the aircraft suffered cascading system failures with the on-board computers, eliminating the automation the aircraft needed to stay aloft. 'Relying on backup instruments, the Air France pilots apparently struggled to restart flight-management computers even as their plane may have begun breaking up from excessive speed,' reports the Wall Street Journal. Computer malfunctions may not be an isolated incident on the Airbus A330, as the NTSB is now investigating two other flights 'in which airspeed and altitude indications in the cockpits of Airbus A330 aircraft may have malfunctioned.'"
Suspect?.... (Score:2, Interesting)
Re:Suspect?.... (Score:4, Insightful)
I dunno, the NTSB usually drags their feet before stating anything. They usually don't make statements about suspicion of what may have happened without specific evidence. This seems like an unusual announcement from them, not their usual style. I wonder if they are compelled to state a truth that they fell won't be properly addressed otherwise. After all, Airbus is built in Europe not the US.
Personally I wonder if they were compelled to state a suspicion that might otherwise not benefit business interests in the US. After all, Boeing is built in the US not Europe.
See how these stupid slurs work in both directions?
Re:Suspect?.... (Score:5, Informative)
I think you both are thinking of the FAA. The whole purpose of the NTSB is to research and investigate civil transportation accidents. They then present their conclusions and recommendations to the regulating authority in that industry. For the airline industry, the FAA then has to implement any recommendations. For the most part, the FAA does not always implement all the recommendations due to cost, business concerns, practicality, national concerns, politics, etc.
In this case, the black boxes have not been recovered and it might be very difficult to pinpoint a cause without them. But the NTSB knows of similar cases that may have occurred in the US that did not lead to accidents. If there job wasn't to ensure that the fleet of aircraft in the US is safe, they may just sit on their asses and do nothing. But it is their job to ensure safety so they will investigate whether this might have led a situation similar to the Air France flight. They will probably share their data with Air France, the Brazilian authorities, Airbus, the FAA, etc when the investigation is concluded.
Re:Suspect?.... (Score:4, Insightful)
The NTSB is the national transportation safety board. The criticism isn't that they shouldn't share their conclusions, it's that they may be politically/economically motivated to "share" mere suspicions which are detrimental to a foreign aircraft manufacturer.
Re: (Score:2, Insightful)
Re:Suspect?.... (Score:4, Insightful)
They just investigate and report which is what you want in an investigative body.
What the NTSB doesn't normally do is report unsubstantiated rumor to newspapers about investigations they have no direct jurisdiction over. While their job is certainly to get to the truth of why a plane crashed, in the absence of good evidence they can spin their version whichever way they choose. Unsurprisingly they have chosen to tell the story in a way that is detrimental to the design philosophy of the A330, just as European investigators would tend to blame Boeing if a 767 crashed and no reliable evidence was available as to why it crashed. Being dedicated to the pursuit of truth and being political are not at all mutually exclusive you know.
Re: (Score:3, Insightful)
Except there's no good evidence here to show that the NTSB is in any way being political; the statement isn't political in and of itself, and there's no evidence that there was any political pressure anywhere being applied.
Here's the facts: other organizations investigating the Air France crash have pointed to possible airspeed malfunctions as a contributing cause. Meanwhile, the NTSB has looked into similar matters and has announced it's looking into two completely separate cases in which it appears that t
Re:Suspect?.... (Score:5, Informative)
Re:Suspect?.... (Score:4, Interesting)
In this case, the black boxes have not been recovered
And at 26 days elapsed time since the crash, its pingers batteries are probably gone to the battery graveyard, never to be seen or heard from again. I doubt by now if it could be heard 100 yards away even by Alvin. One of the ways to save money is by not replacing those batteries on a fixed schedule. And I wouldn't be surprised to have the NTSB admit they can't find that maintenance log either.
I hate to say it, but the detective work to see what happened may well depend on similar instances the pilots managed to handle & restore control.
The comments so far re windows would seem to be a bit premature since even windows can have month + uptimes if the programs it is asked to run are clean. Flight certified software is generally tested till it can handle anything without a people killing failure.
That might surprise some to hear me say that since I'm a fairly famous anti-windows person, given that the only windows install here (XP on my laptop) was nuked and Mandriva-2009.1 installed a couple of months ago & everything else has been some flavor of linux since 1998.
The thing that burns me is that Airbus knows about the problem with the frozen pitot tubes, but didn't insist they be replaced with the retrofit kit at the first overnight stop. So CEO's did what CEO's do best, maximized profits by keeping the engines spooled up & flying. "This" was something that could be handled at scheduled maintenance times in their minds. The question about that for this flight is probably never going to be answered given the black box hasn't been found and likely won't be. But they have at least 2 other flights where only quick action by the pilots saved the day, & they should be acting on it as we read this, not waiting for the NTSB to pronounce guilt before they cut checks. That lack of action should be criminally prosecutable IMO.
--
Cheers, Gene
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Re: (Score:3, Insightful)
Good observation.
The NTSB made an unexpected announcement on the B777 crash in LHR due probably to ice slurrie
in the fuel with uncalled for blame shifting just before the primary investigators in the UK
did their public announcement.
The NTSB going for partisan announcements is a very bad sign directly connected to
Boeing being in dire straits these days. So any published findings of the NTSB
may be completely worthless.
G!
MACC
Re:Suspect?.... (Score:4, Informative)
Actually, the NTSB should be involved in this investigation. I think you can get up to 5 organizations joining to investigate a crash.
1) Country of Origin (Brazil)
2) Country of Destination (France)
3) Country of Carrier (France)
4) Country of Airframe Manufacturer (France/Germany/EU)
5) Country of Engine Manufacturer (US)
Notice that #5 was US. The engines on the plane in question were GE.
Re:Suspect?.... (Score:5, Insightful)
The articles are pure FUD, and the summary is worse. The A330 doesn't need computers to "stay aloft" any more than your PSU needs an OS to power your motherboard. The rest of the functionality is pure gravy.
All these hysterical articles about computer failures always forget that the computers are a BONUS, and it is quite frankly becoming less and less insane to start believing in anti-Europe propaganda. It may indeed be true that pilots are becoming too accustomed to their presence, but in the meantime their high uptime has saved more lives from pilot error than the resulting complacency will ever cost.
This case is especially ridiculous, because modern computer controlled aircraft will actually handle sensor failures BETTER than ones without them. Had the Air France plane had the most up to date equipment, the computers would have used other sensors to estimate a safe range of approximate speeds and provided the pilots with a fast/slow indicator. It's even possible that this is exactly what happened, but something else went wrong.
Even if the computers just shut themselves down, it was still the sensor info that was invalid, so how would a plane without computers have fared any better?
It's also complete bullshit to say that the pilots can't override the computers. In normal flight, the computers *aid* the pilots. For example, avoiding a collision is easier in an Airbus, because pilots can just pull the stick back hard and the computers will automatically give the best possible climb performance, closer to the stall speed than a Boeing pilot would ever dare to go. Meanwhile, the pilot can look out the window instead of at an instrument panel!
This is what happened with the "infamous" crash into the forest. The pilot was too low and slow, and when he did pull up, the aircraft didn't "let him" because even maximum performance wasn't enough and the plane would have dropped like a stone had it been a Boeing. The computers probably saved everyone who did walk away from that crash!
IF the computers actually malfunction, they will turn themselves off. If they don't, the pilots can turn them off manually.
Re: (Score:2, Interesting)
This sounds like it may be a combination of faulty sensors (pitot tubes), crashing computers, newer pilots being more oriented to automated flying than manual flying, and cost saving training cut backs on what to do when things go wrong.
Re:Suspect?.... (Score:5, Funny)
>>Are you seriously suggesting that a person can judge speed 35000 ft over the ocean, at night in a storm by looking out the window?
Well, I might not know if it can be done in airplane, but I have a decent speed feeling when I'm driving, given I have multiple frames of reference. But I would think pilot's would have the same skills also.
Right. It's just the same thing really. That's why car analogies work so well after all.
And of course the pilots could have rolled down a window and stuck out a wet finger to judge the speed of the wind... But the thunderstorm made it too risky (wet finger you see ?).
Re:Suspect?.... (Score:4, Informative)
Coffin corner does not refer to a simple underspeed/overspeed condition. Limiting factor for speed at high altitude is Mach number, not IAS. Exceeding Mcrit leads to shockwave formation on the leading edge of the wing. This moves the centre of pressure rearwards and causes an uncontrollable nose-down pitching moment known as Mach Tuck.
It is this that can cause speeds to rise to the point where they're damaging to the airframe.
At coffin corner, slowing down will give pre-stall buffet, while speeding up gives mach buffet, the precursor to mach tuck. It's almost impossible to tell the difference between the two. Additionally, given the high TAS even small control inputs can have very rapid and extreme effects. It is exceptionally difficult to hand-fly an airliner at high altitude, especially without the benefit of automatic trim.
Re: (Score:3, Insightful)
Now find a safe runway, cover all your windows with heavy black plastic, disconnect your speedometer and try and accurately maintain 60km/h +- 3km/h over the length of the runway. Ten bucks says you park it in a fence a third of the way down.
That's the situation the pilots were in. No points of reference at all.
Re:Suspect?.... (Score:5, Funny)
The actions of the computer? How did the computer make the problem worse?
Here's the chain of events in an A330:
1. Computer in control
2. Sensors fail
3. Computer: "sorry dudes, you're on your own"
4. Pilots in control
5. Pilots: "Fuck"
Here's the same for a B767:
1. Pilots in control
2. Sensors fail
3. Pilots: "Fuck"
Re:Except... (Score:5, Insightful)
No, you're completely wrong. First of all, hydraulics move the control surfaces on all large aircraft. Nothing else has enough power while being light enough.
Old aircraft controlled the hydraulics with mechanical cables, newer ones with electrical cables (Boeing too). The computers in question are not needed for electrical signaling to the hydraulics systems.
The damage required to make the aircraft completely unflyable would be so severe it would affect any aircraft, and it has nothing to do with how well the computers are working.
When the computers went bye-bye, the pilots had complete control of the aircraft, as designed. Furthermore, the computers didn't malfunction - they turned themselves off because they couldn't trust the damaged sensors, but *neither could the pilots*. To characterize this as a computer problem just because they shut down is stupid and dishonest.
Re: (Score:3, Interesting)
You're right and wrong. If you had said that the primary flight computers are optional, you'd be right, but the computers are most certainly not optional in the Airbus FBW design according to the pilots on PPRuNe and several other sources that I consider highly reliable.
The Airbus design requires at least one of the five flight control computers to be working even for direct law (what most people would call "full manual" control). In the event that the three primary computers are down, either of the two s
Re: (Score:3, Insightful)
And nobody is arguing that the fly by wire system is what failed here.
Re: (Score:3, Insightful)
The thing is, these airplanes don't have a "computer override". There's no function that cuts in, takes away control from the pilots, and decides on its own to do what it wants. There are things called "limiters", which prevent the aircraft from exceeding certain well-defined parameters, but those are pretty rigidly defined mathematically within the control laws of the system, and not some "fuzzy" limit determined at the whim of a computer.
In my experience working on fly-by-wire systems, and from my perso
The Wall Street Journal story is misleading, IMO. (Score:5, Insightful)
Air France didn't begin replacing the malfunctioning pitot tubes in the Airbus until April 2009, and the tubes were not replaced yet in the crashed aircraft. The computers were not at fault apparently; there is no reason to suspect a computer malfunction.
Notice that the Wall Street Journal article, Computer Failures Are Probed in Jet Crash [wsj.com], says exactly that: "... seemingly beginning with malfunctioning airspeed sensors..." The "airspeed sensors" are the pitot tubes, which in the Airbus have been known for many years to collect ice in unusual conditions, and to stop giving reliable data.
The computers did what they were programmed to do, apparently. They stopped operating when they calculated that the data was bad. At that point the pilots needed to fly the plane themselves. However, the aircraft was operating in what is known in the aircraft industry as the coffin corner" [wikipedia.org]. There was apparently no way a human could fly the aircraft safely at the speeds necessary to get the craft to France in time, since in a severe thunderstorm the airspeed could not be known accurately enough to prevent overstressing the aircraft.
The Wall Street Journal apparently has NO new information. Here is a quote from the article: "The Air France crash could become the first since the 1980s in which U.S. and European investigators try to piece together a probable cause in a high-profile crash without the help of information from at least one of the plane's black boxes -- the digital recorders containing detailed flight data and cockpit conversations from the flight." There is apparently NO honest reason for the Wall Street Journal to publish an article now, claiming "Computer Failures".
Quote from a June 25, 2009 Aviation Week article, EASA: No Action Soon On A330 Pitot Tubes [aviationweek.com] published three days ago: "The pitot tubes have come under fire in the wake of the crash of AF447 because the accident aircraft, an A330-200, broadcast maintenance messages just before all contact was lost, indicating inconsistent speed information and potential problems with the pitot tube."
Should the Wall Street Journal be trusted for financial information? Apparently the publication did NOTHING to stop the present corruption in the financial departments of the U.S. government. Warren Buffett very publically called derivatives "financial weapons of mass destruction" [bbc.co.uk] beginning in 2002. The corruption was caused by the removal of laws designed to prevent fraud, at the beginning of George W. Bush's first term.
Apparently the Wall Street Journal always serves the profit of its advertisers and others in the U.S. financial industry. If publishing the article at this time and in the way it did indicates anything other than ignorance, it could be theorized that someone connected with the publication has investments in Air France or Airbus Industries.
Other similar incidents concerning the Airbus 330 are being investigated, according to a June 25, 2009 Associated Press news release, US panel probes 2 incidents involving Airbus A330s [nola.com]. The Wall Street Journal has access to the Associated Press, obviously. Why did it publish its misleading article two days later, which appears to blame the "computers"? The REAL story is apparently that apparently such incidents with the Airbus are common.
Here
Re:The Wall Street Journal story is misleading, IM (Score:5, Insightful)
tl;dr version:
On two occasions I have been asked, 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?' I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question.
--Charles Babbage
Re: (Score:3, Interesting)
You seem to know what you're talking about, so I'll ask you. The airframe that I maintain uses all heated air data sensors. They don't just get warm; they are a serious hazard when the plane has just landed or the sensors are being tested. I am curious since I have not worked on commercial liners, but aren't heated probes de rigeur on airframes that fly above a certain altitude?
Or was this an error of the heating system, or what?
Just curious.
-b
Re: (Score:2)
> I dunno, the NTSB usually drags their feet before stating anything.
> They usually don't make statements about suspicion of what may have
> happened without specific evidence.
The United States' NTSB conducts extremely thorough and detailed investigations, with careful intermediate releases of information and preliminary conclusions prior to the issuance of a complete final report. It very deliberately does not leap to conclusions since first impressions and quick conclusions are often wrong. It m
Re: (Score:3, Interesting)
But can't land your plane in a river if it'll save your life.
Automation (Score:5, Insightful)
"The fancier they make the plumbing, the easier it is to stop up the drain." -Scotty
Re: (Score:2, Interesting)
"The fancier they make the plumbing, the easier it is to stop up the drain." -Scotty
An excellent quote, but it doesn't really the problem. For years, aircraft manufacturers have had a philosophical debate over who should be in ultimate control of the aircraft. Boeing says that the pilot should be in direct control of the aircraft, and the computer should assist the pilot. However, many NTSB reports conclude with "pilot error" as the cause of accidents. Therefore, Airbus puts the computer in direct control and the pilot directs the computer on what to do. This was a controversial move,
Re: (Score:2)
It is claimed that although on Airbus aircraft the computer usually prevents the pilot from doing anything stupid, the pilots can still override the computers if necessary. And furthermore, Boeing has apparently adopted similar computer controls as well.
Re:Automation (Score:5, Insightful)
For years, aircraft manufacturers have had a philosophical debate over who should be in ultimate control of the aircraft. Boeing says that the pilot should be in direct control of the aircraft, and the computer should assist the pilot.
Oft repeated nonsense. The ultimate control of an Airbus, during fault conditions, is Direct Law, where the pilot control inputs are transmitted unmodified to the control surfaces, providing a direct relationship between sidestick and control surface.
http://www.airbusdriver.net/airbus_fltlaws.htm
Re: (Score:3, Interesting)
That's too vague to be useful...
Looking at the chart, from 2000-2008, the number of "mechanical failure" crashes exceeds those of simple "pilot error". In other decades, the distribution has been similarly very close.
http://www.planecrashinfo.com/cause.htm [planecrashinfo.com]
I wouldn't quite say that. Airbus is pretty notorious for issues like 10lbs of force being the minim
Re:Automation (Score:4, Insightful)
Sounds nice, but statistically the truth is exactly the opposite here. Over the years, planes have become increasingly safe and reliable with more technology (complexity), accident rates have steadily declined. And even today, the highest-tech aircraft are the safest ones - the big new ones flown by major airlines. Colgan Air 3407 [npr.org] wouldn't have crashed if the pilot hadn't been allowed to nose-up in response to a stall - a patently stupid thing to, which the A330 prevents [slashdot.org] according to another post in this thread.
Meanwhile, on the other side, we have the argument that this Air France A330 crash was due to a software failure that forced the crew to fly without the autopilot. This is theory is highly speculative, yet even if true, all it means is the autopilot is not directly to blame because it wasn't operable during the crash, i.e. humans were in control. So I don't understand the anti-automation spin on this story at all.
Re: (Score:3, Interesting)
Once, just for amusement, I counted up all the Boeing and Airbus crashes over a given period of time (I forget how long it was, but it was long enough for the effect of chance to balance out). Airbus and Boeing had a near-enough identical number of crashes. (I think Boeing had one crash more over the period I looked.)
Since then, I've kept a tally of what planes crash. The two corporations have remained at a dead heat. (No pun intended. Or maybe it was.) Whatever superiority one has in one area is totally ca
Unintended effects (Score:2, Interesting)
Re: (Score:2)
Ironic - sure. Personally I'll wait for the final report.
But looking at safety statistics it seems those systems, at the least, don't make things worse, overall. And in the long term they might only become better (systems improving, tricking down to smaller and smaller planes)
Also, those rumors might have something to do with litigation craze in some parts of the world. It's much more convenient to allow 100 accidents due due to "unfortunate circumstances/force majeure" (harder to point out the blame...or t
Re:Unintended effects (Score:5, Interesting)
Nah. This is all about designing to handle faults you can imagine, and failing to handle faults you can't. Imagining roll-over or stalls are easy. Imagining everything that could go wrong in a wind storm, probably not so much.
Two things (Score:5, Interesting)
Second, the US announcement of the two computer failures, neither of which caused an accident, presumably has nothing at all to do with Boeing's recent embarrassment over continuing delays and cancellations to the Dreamliner, and a desire to damage Airbus?
Re:Two things (Score:5, Insightful)
Flights are getting more and more automated. It used to be up to the pilot to take off and land, and the autopilot would fly the bit in the middle in good conditions. Now the autopilot takes off and lands too. The pilot is there in case of emergencies. But I would still wager that a computer would statistically be better than a human overall, otherwise the airlines wouldn't deploy this.
This case is of a plane travelling at such high speed and altitude that it only has a tiny window of opportunity between breaking up, stalling, or falling into the tempest below. If the computer systems keeping it in that window fail, then the pilot has little chance of actually fixing things. The alternative is to fly a lot more conservatively, with bigger margins of error. That would mean flying slower, and at lower altitude. Which means longer flights, that burn more fuel, hence cost more.
Re: (Score:2)
Well, the plane won't just fall out of the sky if they slow down a little - they should have erred on the side of slowing down and losing some alititude.
However, that isn't without issues if they don't resolve the problem quickly. At lower altitude they burn more fuel - which means there is a good chance they'll need to divert. That's better than disintegrating over an ocean, but it has risks of its own if you're 3 hours away from land.
Re: (Score:2)
Airbus has taken enough damage from their delays with the A400M - Boing hardly needs to heap on. Not to mention that your conspiracy-theory train of thought it beyond absurd.
The revolution has started` (Score:2, Funny)
Re: (Score:2)
So the trains in DC collided because even while the human operator tried applying the breaks the computer overrode the engineer and kept the train moving at a good speed.
Actually the brakes were on for 400 metres before the crash.
R2 SHUT DOWN ALL THE TRASH COMPACTORS ON THE ... (Score:5, Insightful)
Did the flight computer failure mode fail to (dis)engage? I've heard about the manual control levels that an Airbus flight system degrades through. It looks like the computer wouldn't get out of the way soon enough, so the flight crew kicked it in the head.
They received the airplane in a un-recoverable, un-flyable, disintegrating condition from mach turbulence destroying lift and ultimately the aircraft. (coffin corner [wikipedia.org])
Cascading failures generally occur from a synergy of multiple causes. In this case:
- A narrow flight envelope due to altitude and varying wind-speed in the storm. (had they climbed, trying to avoid the storm?)
- Pilot over-reliance on automated flight assist in marginal conditions.
- Failure of physical airspeed instruments due to severe icing from a massive updraft.
- Increased thrust from engines ingesting water contained in the 100mph updraft. (coffin corner!)
- Altitude increase from 100 mph updraft. (coffin corner!)
- Inappropriate computer control responses, destabilizing flight dynamics, leading to overspeed and unrecoverable loss of lift (mach stall).
- Turbulence and chaos of a severe storm masking the initial flight computer deviations.
Aerospace systems are made by humans, but... (Score:5, Interesting)
...the way aerospace (life critical and specialized or specific field oriented) software is created, it is highly bug free, quite the opposite of feature creep bloat you see everywhere else, but even at the code level there is avoidance of function calls that can introduce another level of abstraction and complexity and contribute to bugs and failure. It is in this way that using the process of elimination we can come to some conclusions about where error is or can most certainly exist, philosophy.
On a hardware level, we have redundant backups and check system....
As such there is one area that neither software nor hardware has but only as a secondary or implimentation of, position.
Human error in concepts, beliefs, philosophies, abstraction definition variation, etc... That which exist before the hardware and software and often what hardware and software creation is inspired by, directed by, guide lined by, etc..
If the philosophy base is wrong then its limitations will manifest through the software and hardware created under such a philosophy and eventually show the limitations, via failure to perform.
There are plenty examples of human philosophy errors, such as how it wasn't until the early 1990's that the Catholic Church exonerated Galileo over his observation the earth revolved around the sun.
The Atlanta Centennial park bombing where the 911 system failed because no-one gave the park an address..... or is the philosophy of programming a 911 system to require an address the error? Or is it a good thing that all things needing 911 are at an address?
My pet peeve of the computer industry, the button on the front of the computer marked with a 0 & 1 symbol(s), yet over engineering has resulted in the meaning of those symbols to be more than "off & on" and this went further in removing the hard on off switch so that when the software based power switch failed, you have to physically unplug the computer from the wall, or take teh battery out.
The correct philosophy for such a switch would be a multi position switch, which the consumer doesn't have to know more than is obvious... And ultimately the motivating philosophy behind the software switch is that of creating an OS that needs a shutdown sequence and time for it. When you think of this "0&1" switch, what better representation of distorting the most basic and fundamental concept of computers with overcomplexifabulocation can there possible be?
Software and hardware is not where the error lies in this Air France tragedy, even if there is failure or limitations found there in hardware and software, but the failure is in not providing a manual override. And if the technology has been made to complex for manual control.... then let grandma crawl under the desk to unplug the damn computer....shut it down until the real problem is fixed.
BTW, due to the competitive commercial nature of aerospace software development tools, there is a level of incompatibility between them and as such there is also motive for playing the lockin game regardless of any "unforseen" risk to others. Perhaps there is a place for open source software here!!!
Don't bow down to the stone image (Stone = computer hardware - Image = software) of the beast of man, for the beast is error prone and his image can be no better. Instead take a closer look at the code.... with many eyes.....
Re:Aerospace systems are made by humans, but... (Score:5, Interesting)
Good points.
I will also point out though that systems should be simple to operate, hence Apple for example would never think of having more than two positions for an on/off switch: but in order to achieve that, the system has to be engineered to be truly robust. (I am not saying that Apple equipment is.)
It used to be that equipment had well-defined states, but nowadays everything is programmed using procedural code, and nothing works right anymore.
Electrical engineers are trained in how to design things that really work: they assume asynchronous behavior and concurrency from the outset, and they have design methodologies to create a system that has well-defined states. Procedural code has indeterminate states, unless one uses design paradigms that pair those states, and simulation to test the design. Programmers don't use these techniques: generally speaking, procedural code is hacked together, and so we have laptops OSs that freeze, cellphones that lock up, and airplanes that crash.
The software that exists today is by and large all crap. Procedural programming is appropriate for business apps, but for a reliable real-time system you need an asynchronous design methodology, and you need to prove correctness for critical functions. This is not always done, in aerospace and even for spacecraft software.
Today's programmers don't even have a culture any longer that espouses design and design verification, as opposed to hacking together "code". In their purported quest for "clean code" they have culturally inculcated an obsolete and broken approach.
Re: (Score:2)
Your comments are close to two decades over. Today its all objects which defers the issues yet another step away from reality.
I agree with your other comments.
Any problem in computer science can be solved with one additional layer of indirection. But that usually will create another problem. -- David Wheeler (of ILLIAC fame, not the others)
Re: (Score:2)
Re:Aerospace systems are made by humans, but... (Score:4, Insightful)
What a hideous and offensive generalisation: "everything is programmed using procedural code, and nothing works right anymore." That may be how *some* programmers work, but I give a sh*t, and I write concurrent (and more generally concurrency-safe) code all the time. And I can do that procedurally or by graph reduction or however you like.
As to: "Electrical engineers are trained in how to design things that really work"; do you have any snooty views about all EE grads being better people than all CS grads for example? My first interest was electronics but I don't see a halo.
Any other bigotry about "natural rhythm" or "education shrivelling the uterus".
I must be new here: I expect better reasoned objectivity from someone apparently able to type with reasonable spelling and grammar.
Rgds
Damon
Re: (Score:2)
Re: (Score:2)
While I agree with some of what you say - I don't buy it fully.
Ok, I'm making a smartphone. It should have a simple on-off button - not a 3-way toggle where you get data corruption if you switch it to the 3rd position. It should be hard to bypass the proper shutdown routine (removing the battery counts). So, then the counterproposal is - get rid of the need to do a proper shutdown. Sure, we can do that - no write cache and everything is transaction isolated so that corruptions are impossible. Now the t
Overheard at the Annual Bug of the Year Awards (Score:2)
"So you're nominated because you crashed Word 2007 three times in 20 minutes? Pussy.
Held to a higher standard (Score:2)
This post reminded me of an article [fastcompany.com] that was written a couple years ago about the people who program the space shuttle. I couldn't find a link to it, but I recall a similar article about the software on the Boeing 777; essentially the pilots are sitting in front of a computer screen that they can bring up any piece of data about the airplane, and how these systems must all co-exist without interfering in any way with the flight systems, etc. Pretty interesting reads.
Frankly, the pressure in such an environm
A good Investigation Report (Score:4, Interesting)
I read both the articles posted. They do not qualify as the best investigation reports. They seem to be building "What if" scenarios from all data that is available. Other A330 failures (no recent crashes reported) and Other places where ice in Pitot tubes led to failure (The Wikipedia article has a lot of information on this and planes which had problems notably, the X31 [wikipedia.org].) The investigators are clearly under pressure to say what they have found and they are unable to report "nothing" to the press. With no luck in recovering the Black Box, the investigators (like they talk about Pilots not good at flying aircraft without the aid of in-flight safety systems) have to do it the old forensic way (reminds me of Crichton's Airframe). That is going to take time and the press, the Aircraft companies using A330s are impatient to know why.
Clearly no recent theory has come close to deducing the true reason for the crash. As I remember the first news item that appeared on the AF447 was that the plane "vanished" [cnn.com] from Radar and was sought for by the Brazilian Air Force before the crash site was positively identified. The last exchanges between the Pilot and the Aircraft tower followed by an automated message from the aircraft [wn.com] remain the main clues apart from the debris in this horrific accident.
A330 -- No Margin for Error (Score:4, Interesting)
There are a couple of aspects about the A330 problems that amaze me:
1. How can an airplane be allowed to carry passengers when the margin to airframe disintegration is so narrow? I can understand falling out of the sky if it stalls, but to be able to tear the airplane apart in level flight? What happened to margin of safety in airframe construction -- or is that whole concept now obsolete?
2. If the airplane can send fault messages home, why don't blackbox data streams get sent as well? At least that way there would be some situation info available as opposed to none.
3. In some ways reliance on flight computers is like reliance on spreadsheets or calculators -- if you do not understand what is going on and are not capable of doing it yourself then you cannot tell if the software is correct. Essentially, if the computer says it is so then it is, and you either survive or not.
Re: (Score:2, Insightful)
There are a couple of aspects about the A330 problems that amaze me:
1. How can an airplane be allowed to carry passengers when the margin to airframe disintegration is so narrow? I can understand falling out of the sky if it stalls, but to be able to tear the airplane apart in level flight? What happened to margin of safety in airframe construction -- or is that whole concept now obsolete?
2. If the airplane can send fault messages home, why don't blackbox data streams get sent as well? At least that way there would be some situation info available as opposed to none.
3. In some ways reliance on flight computers is like reliance on spreadsheets or calculators -- if you do not understand what is going on and are not capable of doing it yourself then you cannot tell if the software is correct. Essentially, if the computer says it is so then it is, and you either survive or not.
1. Don't underestimate the power of wind shear. This plane may have been flying straight and level from the grounds point of view (we don't know that), but it was flying in the middle of a storm according to news accounts, likely experiencing some extreme wind forces.
2. The amount of telemetry and logging data generated by any aerospace system (air or space) is humongous, and even with an aircraft (as opposed to low data rate spacecraft), to large to transmit in real-time. In this case, the system did aut
Re:A330 -- No Margin for Error (Score:5, Informative)
There are certification bodies in the US, Europe and many other countries that define what that margin is. The greater the margin the heavier the plane will be, the more fuel it will need and the less load it will be able to carry. So your question really is asking if all these certification bodies are idiots. They are not and are definitely better at it than your armchair speculation. Simple evidence is looking at the rate of crashes and fatalities over time despite the increasing amount of air travel.
How come you don't walk around always wearing a bulletproof vest? Why aren't all your house doors, windows and walls armoured? Because there are costs and benefits and they all have to weighted together to come up with something appropriate.
It would not tear apart in simple level flight within the normal speed range. It could be torn apart going too fast (ie beyond the certification limits imposed by those national bodies) but even then would not be in level flight but likely dropping. It was a massive thunderstorm with huge air currents they were going through. This [wikipedia.org] is an example of what planes can survive where the plane looped, parts flew off and the wings got permanently bent. This [youtube.com] is an example of a certification test for wing strength. FAA regulations require that wings survive 1.5 times (150 percent) of the highest aerodynamic load that the jet could ever be expected to encounter during flight for 3 seconds. That applies to all airliners. The pitot tubes keep being mentioned because they tell you how fast you are going relative to the surrounding air. If they iced over then you don't know and going to slow will result in a stall, going fast increases discomfort and going too fast can result in bits of the plane breaking off.
But to be clear it required abnormal circumstances to break apart. Way beyond anything normally or abnormally encountered. If the circumstances happened with any regularity then you would hear about this kind of accident more often.
The fault messages are generally intended for maintenance so that when the plane arrives they can be repaired as quickly as possible and the plane turned around. They also help with long term tracking of wear and tear. Current blackbox recorders record a huge amount of data which would be infeasible to transmit, especially when it has to go via satellite such as when over oceans. Plane crashes are very rare (that is why they make the news) and it is even rarer to not find the blackboxes.
You overestimate the ability of humans. We are long gone from the days of the lonesome hero sweating it with the control stick. A flying plane is a complex mechanism. You have many control surfaces, air pressures and speeds, centre of gravity, fuel consumption, engine abilities, aerodynamics etc all to take into account. A computer program can do all of that so many times better than a human which includes being both more economical and reacting quicker. The people who make planes are not idiots. Ultimately you have to take the underlying tools you use as is. For example I don't see you insis
This is why airbii make pilots nervous. (Score:3, Interesting)
This is why I really want any airplane I'm flying to LISTEN to me, not argue with me... At no point should a computer be able to override pilot input. Also, i want a solid mechanical link between the controls I'm pushing on and the control surfaces on the wings... That way, even if EVERY computer on the plane dies, I can still control the damn thing...
And yes IAAAP... (I Am An Airline Pilot)
Re:This is why airbii make pilots nervous. (Score:4, Insightful)
> Also, i want a solid mechanical link between the controls I'm pushing on and the control
> surfaces on the wings...
You aren't strong enough to control an A330 with your muscles.
Re: (Score:2)
Not really, as many airplan crashes caused by severed hydraulic lines show. And more often than not all three hydraulic lines were cut.
Good luck with that (Score:4, Interesting)
Speculation (Score:5, Insightful)
Until they know what the actual cause is they should avoid speculation because it does absolutely nothing other then fill media headlines with non-sense.
Re: (Score:2)
Last time I checked the air france black box recorder hasn't been located let alone pulled out of the ocean. Without having the black box how can the NTSB be making speculations as to the cause of the downed flight?
Well, considering the NTSB is a part of the US government, it could be in their interest to make speculations that make a foreign plane manufacturer look bad in order to make a domestic manufacturer look more desirable.
Timely as ever, Slashdot (Score:2)
Investigators suspected the computers a good 3 weeks ago, so I'm not sure how this qualifies as news.
No manual control? (Score:3, Interesting)
What about, you know... manual control?
Sure there are no mechanic cables anymore, but a wire controls the low-level hardware.
But at least it has to have just as basic piece of electronics that has no software or big complexity, and that allows you to manually steer the plane.
(No, that is not too hard to do, even on such big jets. You just have to be more careful about quick actions, stalling the plane & co.)
A piece of electronics that is so simple, that the only thing killing it, is an electric shock right into its mainboard.
Electronics failure is never a cause! (Because: What would that be?)
The reason usually is a software error, that electric shock, or some other external source.
Re: (Score:2)
Why are crashes caused by pilot error better than ones caused by software error? Yes, the computers screw up sometimes. If they screw up less often than the pilots would we are better off. Better yet, how about letting the computer fly the plane while the pilot supervises, ready to intervene if the computer goes wrong? Oh. Wait. That's exactly what they do!
Re:No manual control? (Score:4, Insightful)
I did RTFA, and from what i understand of it it was impossible to get a reliable reading from the instruments in the cockpit, because the computers were failing and the airspeed-detector was unreliable (what seemed to be the primary cause of the failing of the computers). Manual control is fine, IF you know your altitude, airspeed etc. Try driving a car with blinded windows and a defective speedometer and an unreliable rev-meter.
I am not a pilot, but even I can understand that for manual control one has to have reliable data on what the plane is doing, which is exactly what was missing in this case (if the theory we are talking about is right).
Design Philosphy (Score:5, Informative)
Scary stuff.
The Wall Street Journal article oversimplifies the problem with the Airbus
design philosophy. In effect; Too Damn Much reliance on the automated flight
control system for basic safety-of-flight.
A prime example?
Rudder hinges.
Airbus has notoriously
http://en.wikipedia.org/wiki/American_Airlines_Flight_587 [wikipedia.org]
underbuilt the rudder hinges on the A300 (and, no doubt, the A330) in the
interest of lightness and efficiency. They have chosen to rely on the
automated flight control system to limit loads on the structure, instead of
building the necessary robustness into that structure.
This is great when flight conditions are all peachy, but in a thunderstorm, at
night, with sensors (iced-up pitot tubes?) that are prone to failure, well
then you have a failure scenario that the designers never built into their
simulations, and the rescue/recovery teams in the south Atlantic find the
rudder 37 miles from the rest of the wreckage.
Forwarded from a colleague (names redacted);
>> This from a friend and NWA pilot I flew the B-757
>> with out of our Tokyo base.........Now obviously on the A-330
>>
>>
>> Well, I'm sure you have all heard of the Air France accident. I fly
>> the same plane, the A330.
>>
>>
>>
>> Yesterday while coming up from Hong Kong to Tokyo , a 1700nm
>> 4hr. flight, we experienced the same problems Air France had while
>> flying thru bad weather.
>> I have a link to the failures that occurred on AF 447. My list is
>> almost the same.
>> http://www.eurocockpit.com/images/acars447.php [eurocockpit.com]
>>
>> The problem I suspect is the pitot tubes ice over and you
>> loose your airspeed indication along with the auto pilot, auto
>> throttles and rudder limit protection. The rudder limit protection
>> keeps you from over stressing the rudder at high speed.
>>
>> Synopsis;
>> Tuesday 23, 2009 10am enroute HKG to NRT. Entering Nara Japan
>> airspace.
>>
>> FL390 mostly clear with occasional isolated areas of rain,
>> clouds tops about FL410.
>> Outside air temperature was -50C TAT -21C (your not supposed to get
>> liquid water at these temps). We did.
>>
>> As we were following other aircraft along our route. We
>> approached a large area of rain below us. Tilting the weather radar
>> down we could see the heavy rain below, displayed in red. At our
>> altitude the radar indicated green or light precipitation, most
>> likely ice crystals we thought.
>>
>> Entering the cloud tops we experienced just light to moderate
>> turbulence. (The winds were around 30kts at altitude.) After about
>> 15 sec. we encountered moderate rain. We thought it odd to have
>> rain streaming up the windshield at this altitude and the sound of
>> the plane getting pelted like an aluminum garage door. It got very
>> warm and humid in the cockpit all of a sudden.
>> Five seconds later the Captains, First Officers, and standby
>> airspeed indicators rolled back to 60kts. The auto pilot and auto
>> throttles disengaged. The Master Warning and Master Caution
>> flashed, and the sounds of chirps and clicks letting us know these
>> things were happening.
>> The Capt. hand flew the plane on the shortest
>> vector out of the rain. The airspeed indicators briefly came back
>> but failed again. The failure lasted for THREE minutes. We flew the
>> recommended 83%N1 power setting. When the airspeed indicators came
>> back. we were within 5 knots of our desired
Re:Design Philosphy (Score:5, Interesting)
Still human error. (Score:3, Insightful)
Like any other part of the plane, the computer is just another instrument designed and manufactured by people. Blame the programmer, the tester, the lack of analysis. The cause of this accident has nothing to do with computers. They just do what we tell them to. Leave them alone.
Re: (Score:3, Insightful)
If you arbitrarily redefine terms, anything can become anything else...
You're really stretching it to the breaking point, however, as any act of god can be written off as humans not making everything so unbelievably robust as to withstand all possible events.
Broke up from flying 'too fast'? (Score:3, Interesting)
Okay. That's just silly.
There is clearly some major pressure to build a presentable story to the public if they're floating ideas like these ones. If the PR is successful, Official Culture will soon include passenger jets which will break up from 'excessive' flying.
A significant air blast from one of the increasingly frequent falling rocks from outer space could easily account for this disaster, and could explain some of the more peculiar details.
--Quoted from this article [sott.net] which digs into the idea of this event being another case of "Is it just me ore do there seem to be a lot more ROCKS FROM SPACE falling around our ears lately?".
-FL
Re: (Score:2, Funny)
And that's why I always go for the isle seat. :)
Re: (Score:2)
We've had some crazy scare-mongering headlines here before, but this one is definitely up there with the best.
It makes me think "I, Robot" or three evil islamonaziliberal Apple IIs gaining sentience.
Maybe "software causes crash" or "automated systems cause crash" but "computers doomed jet"?
Re: (Score:2)
Less than an average day on the road.
Re: (Score:2)
Wordwide? Sure.
In the USA? Nope. (Not that such a simplistic comparison means anything, but at least let us talk about honest facts.)
http://www-fars.nhtsa.dot.gov/Main/index.aspx [dot.gov]
Re:GPS-based air speed (Score:5, Insightful)
Because GPS knows nothing about *airspeed*.
A GPS recorded speed of 100mph, into a 50mph headwind = 150 mph airspeed.
Re: (Score:2)
+ Insightful
However GP said it wouldn't be accurate, just accurate enough. How high do windspeeds get in safe flying weather (assume a headwind) and would that plus whatever error there is in the gps (probably fairly small) be too much for a go/no go system?
Re: (Score:2, Informative)
It is possible that you are at stall speed and moving several hundreds of km per hour in relation to the ground according to your GPS.
The winds are very strong higher up and if you're in a tail wind, the above scenario is very possible.
Re: (Score:2)
Wow. I would have guessed that in or near a storm system but not in nicer weather. Thanks for the knowledge.
Re: (Score:2)
The inertial nav system all ready has those numbers and might even have a good idea of the last known wind speed.
The problem is that at high cruise the stall speed and the Vne (Never Exceed) can be very close as in two digits in km/hr and hte Va (speed to cruse when you hit turbulence) is within single digits of the stall speed.
Comment removed (Score:4, Informative)
Re: (Score:2)
How high do windspeeds get in safe flying weather
How about over 100mph [wikipedia.org] ?
Re: (Score:2, Informative)
Have you thought this out? Why would flying into a headwind speed up the plane? Just sayin'...
It doesn't speed up, it just faces as much air resistance as it would face flying 150 mph with no wind. That's a quite significant value if you want to figure out if your plane is going to break apart or not...
Re:GPS-based air speed (Score:5, Informative)
Both are important.
Too little airspeed = too little lift and a stall (which is very dangerous on something as big as an airliner, though theoretically recoverable at that altitude granted you'll waste quite a bit of fuel and scare the living daylights out of the passengers).
Too much airspeed = shock waves rip the wings right off the plane. They're not fighters and while those wings actually are pretty strong they can only make them so heavy and be able to carry payload.
Re:GPS-based air speed (Score:4, Informative)
A GPS recorded speed of 100mph, into a 50mph headwind = 150 mph airspeed.
Have you thought this out? Why would flying into a headwind speed up the plane? Just sayin'...
Lets say the pilot wants to fly at 500 knots AIS (Indicated Air Speed). They set ground speed to 500 knots with GPS but the air is going the other way to 100 knots. Airspeed is now 600 knots.
Re: (Score:3, Informative)
To confuse things further - you're not actually using indicated airspeed but true airspeed. :)
The indicated airspeed at those altitudes is often on the order of 300 knots when the plane is really travelling around 500 knots relative to the air and 600 relative to the ground.
Put it this way - in space if you're travelling at mach 20-30 the airspeed indicator would probably read zero. When you hit an air molecule you're moving very fast relative to it, but so few hit the sensor that it reads zero. Anywhere
Re:GPS-based air speed (Score:5, Informative)
it doesn't speed up the plane... but the plane is moving 150 mph compared to the air. That's air speed.
Let's reverse it.. A plane must travel so fast to stay in the air.. let's say 130mph to keep things sane. So if you have a plane flying at 140mph with no wind any direction, the plane will stay up. That same plane could slow to 125mph with a 15mph headwind, and still stay up since in effect the plane is "traveling" at 140mph. Now if there was a TAIL wind of 15mph while the plane was flying at 125mph, the effective speed of the plane would only be 110mph and it wouldn't be able to stay up, it would stall.
Re: (Score:3, Insightful)
To go for the car analogy:
Imagine a (large) conveyor 100 miles long, stable enough for you to drive on in your car. Now drive from it's start to it's end in one hour. The distance you traveled is 100 miles, right?
Now imagine that conveyor moving in the opposite direction (i.e. towards you) at 50 mph. To still get from your starting point to your destination in an hour, you're doing 150 mph road speed. The GPS will still report 100 mph, but your car's tachymetre will report 150 mph, the wheels will revolve a
Re: (Score:2)
In fact, in a small plane, sometimes it's possible to fly above the stall speed into the wind but not move at all relative to the ground.
Re:Short version: (Score:5, Insightful)
Yes, because what we really need is pilots who can program in assembly while rewiring the control panel with their toes. Blindfolded. At mach 15.
You've watched one too many holywood flicks. If your computers crap out while airborne, you don't have time to troubleshoot and diagnose. You just follow the preset procedures, and hope that one of them works before you hit the ground.
Re: (Score:3, Funny)
I think you meant "flight computer" rather than autopilot. But yeah, I hear ya. Also, WAY too many drivers these days have problems operating their car when the throttle sensor craps out, the brake-lines bleed dry, and the steering wheel snaps off.
Now Fred Flinstone ... THERE was a REAL driver! Ah, how I long for the Good Old Days ....
Re: (Score:3, Insightful)
I assume these kinds of modern planes can't even fly without a computer anymore.
You're wrong. They can.
Re:well that's terrifying (Score:5, Informative)
http://www.youtube.com/watch?v=P2KygSyVE58 [youtube.com]
Any belief that Airbus pilots are somehow under the communist thumb and that square-jawed Boeing pilots would heave manfully at the controls and save the say is, um, 100% laughable.
FTA: "...the crew apparently shut down or tried to reboot their primary and secondary computer systems."
Where do they get this garbage? Do they make it up based on their experience with Windows ME?
FWIW, Airbus have *five* flight computers (not "primary" and "secondary") and any one of them can fly the 'plane. If they're all gone then the aircraft is already in little bits so no, you wouldn't ever be under the dashboard trying to 'reboot' them instead of flying (whatever 'reboot' means - they're designed to reboot themselves under a watchdog timer).
Re:well that's terrifying (Score:4, Informative)
This video shows an Airbus pilot switching off the flight computers then barrel rolling an A320:
http://www.youtube.com/watch?v=P2KygSyVE58 [youtube.com]
It's a full scale simulator not a real aircraft, you can see the border of the simulator room projection screen outside of the cockpit. Do you really thing that a man performing a barrel roll with a jumbo jet have the time to explain in a relax manner what's happening ?
It's only a demonstration about how the flight computers limit the human command to stay in flight parameters ( and prevent you to attend stupid maneuver like a barrel roll).
Well duh! (Score:3, Funny)
"you can see the border of the simulator room projection screen outside of the cockpit"
Really? I thought it was the pilot *saying* it's a simulator that gave the game away.
Re: (Score:3, Informative)
I think he's flying a simulator, and not risking an actual airplane.
Straw man troll (Score:3, Informative)
This video shows an Airbus pilot switching off the flight computers then barrel rolling an A320: http://www.youtube.com/watch?v=P2KygSyVE58 [youtube.com]
Give me a break. This whole thing was taken in a simulator, which are *programmed* to behave how they think the airplanes will behave, using recorded data from test flights to help. Because they do not test the airframes in extreme attitudes (especially barrel rolls), they have little to no data with which to program the simulator, making demonstrations like this complete nonsense.
At 3:02 into the video you just posted, the pilot admits, "Not a maneuver you'd normally see in an airliner, and in fact you
Re: (Score:3, Insightful)
a) A barrel roll can be a 1g maneuver, as this video shows: http://www.youtube.com/watch?v=Xp2Uc9XvmjY [youtube.com]
Any aircraft can do it if the pilot is good enough.
b) The article is the one pointing the finger at the machines, nowhere do I see it pointing at the piece of meat who decided to fly through the middle of an enormous thundercloud.
>I'm not sure what you were trying to prove. This video doesn't prove anything.
It clearly shows how many computers are on board, it clearly states th
Re:Straw man troll (Score:4, Informative)
Give me a break. This whole thing was taken in a simulator, which are *programmed* to behave how they think the airplanes will behave, using recorded data from test flights to help. Because they do not test the airframes in extreme attitudes (especially barrel rolls), they have little to no data with which to program the simulator, making demonstrations like this complete nonsense.
There are three replies to GP, and they all totally miss the point, including yours.
He wasn't trying to say that you can do a barrel roll in A320.
He was saying that you can turn off computers in A320, and still retain full manual control of the airctaft.
Re: (Score:3, Informative)
No, a handheld GPS would be useless. It can't give you airspeed or attitude. Also, you need line of sight to the satellites. Next time you're on an airliner, try and use a handheld GPS and see how well that works through the skin of the airplane. My Garmin GPSMAP 195 (an actual aviation handheld GPS) cannot always get a satellite fix in a commercial airliner. In an emergency, its not really a big deal where you are or what your groundspeed is. If you don't know your airspeed or attitude (the two thing