Comments on: The Qantas nosedive – what happened http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/ Life, Culture and Politics from BrisVegas Tue, 14 Feb 2012 07:10:43 +0000 hourly 1 http://wordpress.org/?v=3.3 By: Nabakov http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211167 Nabakov Sun, 19 Oct 2008 17:29:19 +0000 http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211167 Fortunately Airbus have already tested their fly by wire system to <a href="http://au.youtube.com/watch?v=-kHa3WNerjU" rel="nofollow">destruction</a>. Now I wanna see Boeing do the same with the 787 Dreamliner and its Melbourne-cooked cutting-edge composite flight control surfaces. Fortunately Airbus have already tested their fly by wire system to destruction.

Now I wanna see Boeing do the same with the 787 Dreamliner and its Melbourne-cooked cutting-edge composite flight control surfaces.

]]> By: FDB http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211166 FDB Sun, 19 Oct 2008 07:56:07 +0000 http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211166 "The idea of having redundancy both between <b>actual deciding units</i> and the software or systems implemented has been explored and found mostly to be unsatisfactory." Are you referring to the humans present? If not I think you've missed my point, which came from Cap'n Tom's description of bariers to to overriding autopilot. What I'm thinking of is a simple check that what the human is trying to do (contra what the computer says should happen) is not OBVIOUSLY group suicide (or 9/11 for that matter). This condition being satisfied, control is transferred to 'manual' (I do understand that it's not truly manual). I'm not suggesting anything that would replace existing systems, which have been shown to work extremely well compared with 'manual' systems, but a referee system for situations like these that happen once every decade or so. “The idea of having redundancy both between actual deciding units and the software or systems implemented has been explored and found mostly to be unsatisfactory.”

Are you referring to the humans present? If not I think you’ve missed my point, which came from Cap’n Tom’s description of bariers to to overriding autopilot. What I’m thinking of is a simple check that what the human is trying to do (contra what the computer says should happen) is not OBVIOUSLY group suicide (or 9/11 for that matter). This condition being satisfied, control is transferred to ‘manual’ (I do understand that it’s not truly manual).

I’m not suggesting anything that would replace existing systems, which have been shown to work extremely well compared with ‘manual’ systems, but a referee system for situations like these that happen once every decade or so.

]]> By: Robert Merkel http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211165 Robert Merkel Sat, 18 Oct 2008 21:27:05 +0000 http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211165 Jacques: ah, yes, N-version programming. Your summary of the situation is basically correct. Jacques: ah, yes, N-version programming. Your summary of the situation is basically correct.

]]> By: Jacques Chester http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211164 Jacques Chester Sat, 18 Oct 2008 16:24:45 +0000 http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211164 <blockquote>Do we need an entirely separate and almost always redundant system to resolve conflict in control between humans and the computer? A simpler, cruder version of the altitude/attitude sensors, that can be an automatic umpire if flesh and chips disagree?</blockquote> This just moves your risk to another area. Aerospace code is probably the most reliable in the world, because the consequences of failure are so dire. Boeing and Airbus spend serious money and effort on making sure it's as safe as possible; but even so mistakes get made. Aviation has had disasters caused by various sorts of systemic, procedural or engineering failures since the very beginning. The idea of having redundancy both between actual deciding units and the software or systems implemented has been explored and found mostly to be unsatisfactory. Boeing did a very large study and found that having multiple independent implementations of a critical piece of software did not reduce the number of bugs; rather they found that each group tended to make bugs in the same complex areas of work.

Do we need an entirely separate and almost always redundant system to resolve conflict in control between humans and the computer? A simpler, cruder version of the altitude/attitude sensors, that can be an automatic umpire if flesh and chips disagree?

This just moves your risk to another area.

Aerospace code is probably the most reliable in the world, because the consequences of failure are so dire. Boeing and Airbus spend serious money and effort on making sure it’s as safe as possible; but even so mistakes get made. Aviation has had disasters caused by various sorts of systemic, procedural or engineering failures since the very beginning.

The idea of having redundancy both between actual deciding units and the software or systems implemented has been explored and found mostly to be unsatisfactory. Boeing did a very large study and found that having multiple independent implementations of a critical piece of software did not reduce the number of bugs; rather they found that each group tended to make bugs in the same complex areas of work.

]]> By: Jack Hackett http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211163 Jack Hackett Sat, 18 Oct 2008 04:40:39 +0000 http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211163 Thanks for the analogy to driving around a roundabout. Capt. Tom. Any I am glad you are a Capt., not a Major, Major Tom had to communicate with ground control with disastrous consequences for him. To be serious though I approach every flight as my last. I buckle up and stay so unless in the loo. I listen to the flight instructions and check my exit. I assume it will crash and being of a fatalistic bent, it doesn't bother me. Some say I am safer in a plane than driving to the airport, but in the latter case I have some control over the management of disaster than I do in a plane. And it does concern me that pilots have so little control over adverse computer events. Then again I have had a taxi driver from the Urals smelling strongly of alcohol and with needle marks on his forearms drive me to Eagle Farm airport, and I survived that. Jack Hackett Thanks for the analogy to driving around a roundabout. Capt. Tom. Any I am glad you are a Capt., not a Major, Major Tom had to communicate with ground control with disastrous consequences for him.

To be serious though I approach every flight as my last. I buckle up and stay so unless in the loo. I listen to the flight instructions and check my exit. I assume it will crash and being of a fatalistic bent, it doesn’t bother me.

Some say I am safer in a plane than driving to the airport, but in the latter case I have some control over the management of disaster than I do in a plane.

And it does concern me that pilots have so little control over adverse computer events.

Then again I have had a taxi driver from the Urals smelling strongly of alcohol and with needle marks on his forearms drive me to Eagle Farm airport, and I survived that.

Jack Hackett

]]> By: Colonel of Truth http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211162 Colonel of Truth Fri, 17 Oct 2008 14:02:53 +0000 http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211162 A little OT but I must take issue with comments about Qantas service. I'm just back from a Brisbane-Barcelona cattle class trip on a QF/BA codeshare. First time I've flown QF internationally for ~20 years and what a pleasant surprise. Seat pitch, cabin crew attitude/service, cleanliness, cockpit information, toilet availability all great. Even the food was better than edible. And the little touches made a difference (frequent water topups in flight, hot towels, a time line on the menu so one knew what would happen when). I was happy to give QF a pat in a passenger survey. Pity it seems not to trickle down to all QF domestic flights, although some are good. But don't ask about BA; 'excruciating' is putting it kindly. A little OT but I must take issue with comments about Qantas service. I’m just back from a Brisbane-Barcelona cattle class trip on a QF/BA codeshare. First time I’ve flown QF internationally for ~20 years and what a pleasant surprise. Seat pitch, cabin crew attitude/service, cleanliness, cockpit information, toilet availability all great. Even the food was better than edible. And the little touches made a difference (frequent water topups in flight, hot towels, a time line on the menu so one knew what would happen when). I was happy to give QF a pat in a passenger survey. Pity it seems not to trickle down to all QF domestic flights, although some are good. But don’t ask about BA; ‘excruciating’ is putting it kindly.

]]> By: RumRebellious http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211161 RumRebellious Fri, 17 Oct 2008 03:23:30 +0000 http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211161 Ouch Joe2 @31! Just curious, is there any truth to the conspiracy that Lufthansa completely replaced their on-board flight navigation systems in the 1990's because they discovered they could be controlled remotely? Ouch Joe2 @31! Just curious, is there any truth to the conspiracy that Lufthansa completely replaced their on-board flight navigation systems in the 1990′s because they discovered they could be controlled remotely?

]]> By: steveh http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211160 steveh Fri, 17 Oct 2008 02:01:15 +0000 http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211160 Hi Robert, Thanks to you and Tom for the info, I must admit I was a bit surprised that the limits on controllability would allow such a dramatic command at this stage of flight (that said I don't have the figures for rotational rates). Another problem is the crew can end up spending a fair amount of time attempting to diagnose what-the-hell is going on. The Adam Air accident (PK-KKW) shows how this can get to an extreme point - albeit with poor maintenance practices thrown in. One large factor is the limitation on what error messages are/n't displayed. In lab instrumentation it's fine to have a tome showing every error code under the sun, but for time-critical applications it has to be limited. From my reading of accident reports (not an LAME mind you!) it seems that sensor failures aren't unknown and the software limits what is displayed. If a "redundancy breakthrough" occurs then there may be no indication - thus leading to the good old "disconnect everything and go to primary instruments". Tom - my limited understanding is that the automation can be quite difficult to disconnect on the modern aircraft - is this true? Hi Robert,
Thanks to you and Tom for the info, I must admit I was a bit surprised that the limits on controllability would allow such a dramatic command at this stage of flight (that said I don’t have the figures for rotational rates).
Another problem is the crew can end up spending a fair amount of time attempting to diagnose what-the-hell is going on. The Adam Air accident (PK-KKW) shows how this can get to an extreme point – albeit with poor maintenance practices thrown in.
One large factor is the limitation on what error messages are/n’t displayed.
In lab instrumentation it’s fine to have a tome showing every error code under the sun, but for time-critical applications it has to be limited. From my reading of accident reports (not an LAME mind you!) it seems that sensor failures aren’t unknown and the software limits what is displayed. If a “redundancy breakthrough” occurs then there may be no indication – thus leading to the good old “disconnect everything and go to primary instruments”.
Tom – my limited understanding is that the automation can be quite difficult to disconnect on the modern aircraft – is this true?

]]> By: FDB http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211159 FDB Thu, 16 Oct 2008 23:47:11 +0000 http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211159 Do we need an entirely separate and almost always redundant system to resolve conflict in control between humans and the computer? A simpler, cruder version of the altitude/attitude sensors, that can be an automatic umpire if flesh and chips disagree? Do we need an entirely separate and almost always redundant system to resolve conflict in control between humans and the computer? A simpler, cruder version of the altitude/attitude sensors, that can be an automatic umpire if flesh and chips disagree?

]]> By: Robert Merkel http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211158 Robert Merkel Thu, 16 Oct 2008 22:18:43 +0000 http://larvatusprodeo.net/2008/10/15/the-qantas-nosedive-what-happened/#comment-211158 Tom, thanks for your comments. I suppose - as the computer guy here - my counterpoint to the concern about fly-by-wire is that controlled flights into terrain - that is, a functioning aircraft being flown into the ground under pilot control - happen on a yearly or so basis. Tom, thanks for your comments. I suppose – as the computer guy here – my counterpoint to the concern about fly-by-wire is that controlled flights into terrain – that is, a functioning aircraft being flown into the ground under pilot control – happen on a yearly or so basis.

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