Computers in Aircraft
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Computers in Aircraft
The aircraft is relatively new, and computers are.. well... computers... so it's highly unlikely that this is a result of poor maintenance.
Windows crashes, Blue screen of death. Most IT people shrug their shoulders and say, give it a reboot. Everyone seems to be very accepting that computers can at times (some frequently) fail for UNKNOWN reasons, and yet everyday millions of people naively walk onto aircraft that have computers controlling their very lives....
I just dont get how people can be satisfied with that level of service from a product.
On the lighter side, see below for further explanation.
MS-DOS Airline
Everybody pushes the airplane until it glides, then they jump on and let the plane coast until it crashes again, then they push again jump on again, and so on.
Mac Airline
All the stewards, stewardesses, captains, baggage handlers, and ticket agents look the same, act the same, and talk the same. Every time you ask questions about details, you are told you don't need to know, don't want to know, and would you please return to your seat and marvel at the image quality of the in-flight movie.
OS/2 Airline
To board the plane, you have your ticket stamped ten different times by standing in ten different lines. Then you fill our a form showing where you want to sit and whether the plane should look and feel like an ocean liner, a passenger train or a bus. If you succeed in getting on the plane and the plane succeeds in taking off the ground, you have a wonderful trip...except for the time when the rudder and flaps get frozen in position, in which case you will just have time to say your prayers and get in crash position.
Windows 95 Airline
The airport terminal is nice and colorful, with friendly stewards and stewardesses, and easy access to the plane. After the plane arrives, 6 months late, you have a completely uneventful takeoff... then, once in the air the plane blows up without any warning whatsoever.
Windows NT Airline
All the passengers carry their seats out onto the tarmac, placing the chairs in the outline of a plane. They all sit down, flap their arms and make jet swooshing sounds as if they are really flying.
Windows XPAirline
The airplane is very pretty, and each passenger gets to choose their own colour and pattern for the paintwork, and their own favourite engine noise. Unfortunately the plane is so heavy and so slow that it is unable to get airbourne,and crashes at the end of the runway. When parked in the hangar, unresolved security bugs in the planes doors AND windows AND luggage-bay AND engines AND wings AND body panels allow theives to break in and steal all the seats.
Unix Airline
Each passenger brings a piece of the airplane and a box of tools to the airport. They gather on the tarmac, arguing constantly about what kind of plane they want to build and how to put it together. Eventually, they build several different aircraft, but give them all the same name. Some passengers actually reach their destinations. All passengers believe they got there.
BEOS Airline
There is no airplane. The passengers gather and shout for an airplane, then wait and wait and wait and wait. A bunch of people come, each carrying one piece of the plane with them. These people all go out on the runway and put the plane together piece by piece, arguing constantly about what kind of plane they're building. The plane finally takes off, leaving the passengers on the ground waiting and waiting and waiting and waiting. After the plane lands, the pilot telephones the passengers at the departing airport to inform them that they have arrived.
Newton Airline
After buying your ticket 18 months in advance, you finally get to board the plane. Upon boarding the plane you are asked your name. After 46 times, the crew member recognizes your name and then you are allowed to take your seat. As you are getting ready to take your seat, the steward announces that you have to repeat the boarding process because they are out of room and need to recount to make sure they can take more passengers.
VMS Airline
The passengers all gather in the hangar, watching hundreds of technicians check the flight systems on this immense, luxury aircraft. This plane has at least 10 engines and seats over 1,000 passengers. All the passengers scramble aboard, as do the necessary complement of 200 technicians. The pilot takes his place up in the glass cockpit. He guns the engines, only to realise that the plane is too big to get through the hangar doors.
Linux Airline
Disgruntled employees of all the other OS airlines decide to start their own airline. They build the planes, ticket counters, and pave the runways themselves. They charge a small fee to cover the cost of printing the ticket, but you can also download and print the ticket yourself for free. When you board the plane, you are given a seat, four bolts, a wrench and a copy of the seat-HOWTO.html. Once settled, the fully adjustable seat is very comfortable, the plane leaves and arrives on time without a single problem, the in-flight meal is wonderful. You try to tell customers of the other airlines about the great trip, but all they can say is, "You had to do what with the seat?"
<edit spelling>
Last edited by Dogimed; 19th Sep 2008 at 01:44.
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'Dogimed' enjoyable post & somewhat relevant!
This thread has me having to tell you lot out there something funny.
I was the other day paxing back to ML Fm Syd on a virgin( ahhh those where the days
) & I noticed a professional looking woman tapping away madly on her lap top very fast & during her typing the thing crashed big time!, she was most p*ssed off I can tell. Good job she wasn't plugged into the A/c flight computers or we would have had that blue screen of death!
Computers afterall tell us nothing we don't already know,(if they did then I'd be rich with the Lotto numbers known in advance) they just put what info has been fed into it all together so as we don't have to crunch the numbers ourselves, even we as human 'crash' sometimes!
CW
This thread has me having to tell you lot out there something funny.
I was the other day paxing back to ML Fm Syd on a virgin( ahhh those where the days
) & I noticed a professional looking woman tapping away madly on her lap top very fast & during her typing the thing crashed big time!, she was most p*ssed off I can tell. Good job she wasn't plugged into the A/c flight computers or we would have had that blue screen of death! Computers afterall tell us nothing we don't already know,(if they did then I'd be rich with the Lotto numbers known in advance) they just put what info has been fed into it all together so as we don't have to crunch the numbers ourselves, even we as human 'crash' sometimes!CW
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Is it worth pointing out (to those that might be genuinely concerned) that 'mission critical' systems are
- more heavily tested
- running on much more proven, well tested, less stressed hardware
- employ techniques like multiple independant systems, cross checking and voting out any units whose results don't compare well with others in the set.
- don't have idiot users installing goodness only knows what crap off the interweb on them.
And a whole host of other stuff I don't know about?
Nah.. enjoy the humour
But really, such systems are a specialist subject, and a million miles away from your corporate laptop.
- more heavily tested
- running on much more proven, well tested, less stressed hardware
- employ techniques like multiple independant systems, cross checking and voting out any units whose results don't compare well with others in the set.
- don't have idiot users installing goodness only knows what crap off the interweb on them.
And a whole host of other stuff I don't know about?
Nah.. enjoy the humour
But really, such systems are a specialist subject, and a million miles away from your corporate laptop.
'140' have tears in my eyes tnxs to that link!! So true!Join Date: Mar 2006
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I don't think computers themselves are the problem per se.
Mark1234 has highlighted a number of very good points.
Computers will do EXACTLY as they are told, no more no less.
Programmers have had a saying for a while: "Garbage in, garbage out", meaning that if the code that goes into a computer is rubbish, then the output will be rubbish.
The weak links in the chain are the programmers, managers, bean counters etc. who are liable to stop the coding before it is truly finished, and then rely on patches and updates to address problems generally only after they have been reported by people who have found them.
In aviation where supposedly the primary mandate is safety, you would expect that an end product be much more complete than say a computer that is designed for home use.
But in the commercial world, to completely debug software can take a ridiculous amount of time (and money). Generally, it takes 10% of the time and budget to do 90% of the work. Consequently, it's the fine tuning and debugging that takes the bulk of the time and budget.
Add to that the fact that some errors and problems will not become apparent until the software and hardware has been integrated into the complex system it was designed for (AKA an aircraft), in an operational environment. Any amount of stress testing is liable to miss certain situations or configurations which cause errors, unless you spend massive amounts of time testing. Sometimes this can only ever really be done "on the fly" in an operational environment.
I trust computers for the most part, but I don't necessarily trust the beancounters who rationalise the cost cutting which inevitably leads to an incomplete product being launched.
Microsoft Windows? Don't get me started.....
Mark1234 has highlighted a number of very good points.
Computers will do EXACTLY as they are told, no more no less.
Programmers have had a saying for a while: "Garbage in, garbage out", meaning that if the code that goes into a computer is rubbish, then the output will be rubbish.
The weak links in the chain are the programmers, managers, bean counters etc. who are liable to stop the coding before it is truly finished, and then rely on patches and updates to address problems generally only after they have been reported by people who have found them.
In aviation where supposedly the primary mandate is safety, you would expect that an end product be much more complete than say a computer that is designed for home use.
But in the commercial world, to completely debug software can take a ridiculous amount of time (and money). Generally, it takes 10% of the time and budget to do 90% of the work. Consequently, it's the fine tuning and debugging that takes the bulk of the time and budget.
Add to that the fact that some errors and problems will not become apparent until the software and hardware has been integrated into the complex system it was designed for (AKA an aircraft), in an operational environment. Any amount of stress testing is liable to miss certain situations or configurations which cause errors, unless you spend massive amounts of time testing. Sometimes this can only ever really be done "on the fly" in an operational environment.
I trust computers for the most part, but I don't necessarily trust the beancounters who rationalise the cost cutting which inevitably leads to an incomplete product being launched.
Microsoft Windows? Don't get me started.....
This one is urban myth but still worth a laugh....
At a recent computer expo (COMDEX), Bill Gates reportedly compared the computer industry with the auto industry and stated, "If GM had kept up with the technology like the computer industry has, we would all be driving $25.00 cars that got 1,000 miles to the gallon."
In response to Bill's comments, General Motors issued a press release stating, "If GM had developed technology like Microsoft, we would all be driving cars with the following characteristics:
In response to Bill's comments, General Motors issued a press release stating, "If GM had developed technology like Microsoft, we would all be driving cars with the following characteristics:
- For no reason whatsoever, your car would crash twice a day.
- Every time they painted new lines on the road, you would have to buy a new car.
- Occasionally your car would die on the freeway for no reason. You would have to pull over to the side of the road, close all of the windows, shut off the car, restart it, and reopen the windows before you could continue. For some reason you would simply accept this.
- Occasionally, executing a maneuver such as a left turn would cause your car to shut down and refuse to restart, in which case you would have to reinstall the engine.
- Only one person at a time could use the car unless you bought "CarNT," but then you would have to buy more seats.
- Macintosh would make a car that was powered by the sun, was reliable, five times as fast and twice as easy to drive -- but it would only run on five percent of the roads.
- The oil, water temperature and alternator warning lights would all be replaced by a single "general protection fault" warning light.
- The airbag system would ask, "Are you sure?" before deploying.
- Occasionally, for no reason whatsoever, your car would lock you out and refuse to let you in until you simultaneously lifted the door handle, turned the key and grabbed hold of the antenna.
- GM would require all car buyers to also purchase a deluxe set of Rand McNally Road maps (now a GM subsidiary), even though they neither need nor want them. Attempting to delete this option would immediately cause the car's performance to diminish by 50 percent or more. Moreover, GM would become a target for investigation by the Justice Department.
- Every time GM introduced a new car, car buyers would have to learn to drive all over again because none of the controls would operate in the same manner as the old car.
- You'd have to press the "start" button to turn the engine off.
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Rather scary really...
Unless they start telling lies to each other...Ref QF recent incident.
Dog
Computers will do EXACTLY as they are told, no more no less.
Dog
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Correction:
Computers will THEORETICALLY do what they are told to do. Silicon is not 100% reliable and chips do degrade and fail. Not very much if they are high grade as in aviation (mostly), but they are still subject to aging and heat stresses, electrical surges and spikes, etc. Even the simple switching on and off causes stresses to an electrical circuit.
The two major problems with computer reliability:
Humans program them. As the systems get more complex, so does the software required to run it. The variables needed to be tested increase exponentially and there comes a point where the testing for all possibilities becomes impossible or so prohibitively expensive that it is put into extremely unlikely category of failure and simply not done. Only the engineers may ever know what the potential faults are.
I call them 'undocumented features'.
The second is that computers have deep and dark souls. With many systems, the startup diagnostic is a compromise between testing functionality and time. To thoroughly test a hardware set on boot up could take minutes, even hours. We get frustrated when the GPS isn't on instantly, right? Thus one will never know if a particular RAM chip is not quite remembering everything or a particular transistor or transistor set is giving the correct output.
Overenthusiastic reliance on computers is quite unwise, IMHO.
sc
Computers will THEORETICALLY do what they are told to do. Silicon is not 100% reliable and chips do degrade and fail. Not very much if they are high grade as in aviation (mostly), but they are still subject to aging and heat stresses, electrical surges and spikes, etc. Even the simple switching on and off causes stresses to an electrical circuit.
The two major problems with computer reliability:
Humans program them. As the systems get more complex, so does the software required to run it. The variables needed to be tested increase exponentially and there comes a point where the testing for all possibilities becomes impossible or so prohibitively expensive that it is put into extremely unlikely category of failure and simply not done. Only the engineers may ever know what the potential faults are.
I call them 'undocumented features'.
The second is that computers have deep and dark souls. With many systems, the startup diagnostic is a compromise between testing functionality and time. To thoroughly test a hardware set on boot up could take minutes, even hours. We get frustrated when the GPS isn't on instantly, right? Thus one will never know if a particular RAM chip is not quite remembering everything or a particular transistor or transistor set is giving the correct output.
Overenthusiastic reliance on computers is quite unwise, IMHO.
sc
It would be a very brave regulatory authority that certified the first pilotless passenger aeroplane. As a few others have highlighted, it is the testing of the software that is time consuming and costly. As someone once told me, you can only test for what you have specified. What this means is that you can't test the software for unintended consequences, or to paraphrase Donald Rumsfeld, you can test for known knowns but you can't test for known unknowns. This applies to the inital software installed in an aircraft computer (not just the FMS but all the computers that drive the thing) but to all subsequent software upgrades. The only way "glitches" become known knowns is through operational experience.
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Once upon a time planes sported only one engine, only one pilot. This was acceptable when aviation was geting off the ground so to speak, but they crashed. Then came along planes with more than one engine & more than one pilot. A second pilot, a flight engineer, a navigator & even a radio operator all needed on the day for safe flight etc, presumably, but they still crashed. Introduce modern aviation where we now have FBW, multiple redundancies of every critical system, we still have 2X pilots but handling a far more complexe craft than ever first imagined by our aviation forefathers, these too still crash. Computers in planes are just part of the aviation advancement, who knows where it will go from here. Pilot-less craft flying outside the stratosphere? Probably but am sure they too will have 'crashes'.
I guess what I am getting at here is that computers don't prevent anything, they enhance it (safety & running costs etc) but they will never prevent accidents. In fact they (computers) enhance/create problems/accidents just by there very nature of having the pilot out of the loop so much these days. As we have read/seen in modern times not to mention recently this is definetly the case (the A320 into the trees is a classic case). It's more to move more people than ever before to the far corners of the world with as little cost as possible is why we have computers controlling A/C.
Progress, not always a good thing!
CW
I guess what I am getting at here is that computers don't prevent anything, they enhance it (safety & running costs etc) but they will never prevent accidents. In fact they (computers) enhance/create problems/accidents just by there very nature of having the pilot out of the loop so much these days. As we have read/seen in modern times not to mention recently this is definetly the case (the A320 into the trees is a classic case). It's more to move more people than ever before to the far corners of the world with as little cost as possible is why we have computers controlling A/C.
Progress, not always a good thing!
CW
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Capt Wally,
What a great post... ...
I am not looking at computers preventing a crash, nor assisting pilots with provision of information, or control of unstable craft. I am looking at computers controling the LOGIC of a flight. (ie: ooh, if we do this it will stall, I dont want it to stall so I wont allow it. <BANG> Plane hits mountain)
Computers take the logic of safety and protection of aircraft as opposed to safety and protection of people at the expense of the aircraft.
Dog
What a great post... ...
I am not looking at computers preventing a crash, nor assisting pilots with provision of information, or control of unstable craft. I am looking at computers controling the LOGIC of a flight. (ie: ooh, if we do this it will stall, I dont want it to stall so I wont allow it. <BANG> Plane hits mountain)
Computers take the logic of safety and protection of aircraft as opposed to safety and protection of people at the expense of the aircraft.
Dog
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Agreed - great post.
I'd argue (as would I suspect many designers) that protecting the aircraft IS protecting the passengers, but the computer does what it's programmed to. By my understanding, by the time the FBW said NO, the airbus was already too low and slow - FBW or not it was going into the trees.
Alternatively, there is no protection, I do this, we stall.... and <BANG> Plane hits mountain... just as terminally!
I'm not particularly pro FBW. I'm just mildly irritated by the continual comparison to cheap mass produced to a budget desktop software. It's a bit like saying 'my scooter broke down so we shouldn't use engines in aeroplanes'.
Actually, I think the point was in Dogimed's first post:
Those reasons are perfectly capable of being known, it's just not economically viable to answer them - would you pay 3x as much for an office suite that didn't crash? How about if it was flying your plane?
I'd argue (as would I suspect many designers) that protecting the aircraft IS protecting the passengers, but the computer does what it's programmed to. By my understanding, by the time the FBW said NO, the airbus was already too low and slow - FBW or not it was going into the trees.
(ie: ooh, if we do this it will stall, I dont want it to stall so I wont allow it. <BANG> Plane hits mountain)
I'm not particularly pro FBW. I'm just mildly irritated by the continual comparison to cheap mass produced to a budget desktop software. It's a bit like saying 'my scooter broke down so we shouldn't use engines in aeroplanes'.
Actually, I think the point was in Dogimed's first post:
Everyone seems to be very accepting that computers can at times (some frequently) fail for UNKNOWN reasons
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Good thread,
re: the comment about ever getting a pilotless aircraft certified-I dont think authorities would ever have to do it. No one will build it because no one in their right mind would fly on one.
Not in my lifetime anyway.
re: the comment about ever getting a pilotless aircraft certified-I dont think authorities would ever have to do it. No one will build it because no one in their right mind would fly on one.
Not in my lifetime anyway.
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Those reasons are perfectly capable of being known, it's just not economically viable to answer them - would you pay 3x as much for an office suite that didn't crash? How about if it was flying your plane?
There is no room for this in aviation, thus the price value comparison is not relevant.
Perhaps the most salient point is that perfect, safe design of an aircraft capable of handling all the variables out there is akin to the perpetual wheel. Designers are still only dealing with the laws of physics and there are too many of them to design a perfect system.
There will never be a perfectly safe aircraft, only a compromise between what we know can happen and what we don't as mentioned earlier. The best and most reliable system we have is the human, IMO, this is the system we should spend a lot more energy on perfecting, training, educating and understanding.
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s_check: I think we agreeing - shrinkwrap is driven by pure greed money is the raison d'etre, and prime concern. Aviation control systems just have to be right.
Pilotless aircraft will happen I'm sure - Emotionally I hope not, I'm a pilot! However a lot of the systems questions are on their way to being answered - look at things like Global Hawk.. Maybe it'll be an end to layovers and such; you turn up and fly your flight from the 'office' never leave the home base. I agree it'll be a long time before that's acceptable to people though.
That said I'm far less convinced that the human is the 'best' system - we have our own quite insidious failure modes, even when multiply redundant... and as for testing
Pilotless aircraft will happen I'm sure - Emotionally I hope not, I'm a pilot! However a lot of the systems questions are on their way to being answered - look at things like Global Hawk.. Maybe it'll be an end to layovers and such; you turn up and fly your flight from the 'office' never leave the home base. I agree it'll be a long time before that's acceptable to people though.
That said I'm far less convinced that the human is the 'best' system - we have our own quite insidious failure modes, even when multiply redundant... and as for testing
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Most IT people shrug their shoulders and say, give it a reboot.
Many years ago now, myself and an Electrician were flown up to Darwin one night to fix/rescue a B767 that had aborted takeoff with a (false) fire warning.
After we had fixed the problem we stayed at the Airport and slept on the Aircraft for a few hours, as there wasn't time to go to a Hotel.
When it was time to prepare the Aircraft for departure, we fired up the APU and dozens and dozens of fault messages came up, most of which we had never even seen before.
We completely depowered the Aircraft, waited a few minutes, then powered it all up again (as you would do with a computer) and NO problems.
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Yes Mark, agree completely, except:
This is the most unfortunate part, that we as humans have neither the understanding nor the capacity (currently) to embrace our own capabilities, place little or no confidence in ourselves and consequently create a blockage to our own evolution. We compensate by creating inferior and fallible systems in order to justify or excuse our lack of progress, laziness, refusal to accept responsibility and our need to have something to blame.
I am not saying we should not develop systems to enable us to fly better, safer, etc. What I am saying is we should not do it at the expense of our own skillset and progress. To err is human, yet to hand control to a machine of our lives is inhuman and foolish.
That said I'm far less convinced that the human is the 'best' system - we have our own quite insidious failure modes, even when multiply redundant... and as for testing
I am not saying we should not develop systems to enable us to fly better, safer, etc. What I am saying is we should not do it at the expense of our own skillset and progress. To err is human, yet to hand control to a machine of our lives is inhuman and foolish.