Pragmatic 11A: Cause And Effect Follow-up 1

20 March, 2014


Follow up (Part A) to Cause And Effect with more detail on the Aeroperu crash courtesy of listener Dean Lombard.

Transcript available
This pragmatic follow-up a four episode one cause-and-effect and then Alexander McAllister judging a gun and thanks that so I had an excellent's are a great fireman email from our John by the name of Dean Lombard and one of the great things about the fact that there were some people listening the show is that every now and then you come across somebody who's got a lot more debt in-depth knowledge and experience about the topics that you're talking about and it just so happens that Dean is somewhat of a fan of the disorder aircraft are air crash investigations and he actually has a book are the book itself is called black box is a link to it in the show notes and are it's basically was it was published by Yarm Harper Collins in 1998 and edited by Malcolm MacPherson and what is is that the full title is the blackbox cockpit voice recorder accounts of in-flight accidents and it actually does mention the ER Aero proof our crash that we we mentioned are in the year cause-and-effect domain episode so he's written a very good very good list of a couple of extra details I'd like to read out exits from his emails estimate sensibly to emails are on the subject are so visible regarding the the CVR the conference SI CBO Sir cockpit voice recorder so the CVR transcripts are he says is a very harrowing read at the pilot and co-pilot are completely baffled for getting such contradictory information by getting a stall warning and overspeed warning at the same time even though they are applying the spoilers and had cut the engines back the pilots still believed the overspeed warning above the stick shaker stall warning so this just pausing every second wet when your aircraft without more aircraft are about to stall in other words they're not going fast enough in order actually stay are in the air that you drop out here if you go any slower that that sticks literally shake that concert was brought in a year after decade or two earlier the idea is that before autopilot was really a thing and they are air pilots would sometimes fall asleep you and they would they would ease back on the speed of the plane it would gradually slowdown is about to stall this that the sticks literally then a program to shake so I would shake so that they would wake up the pilot that was the whole idea of the stick shaker Gaelic rumble strips on the side of the road you get exactly got exactly good analogy just like the sort of thing and yet are very effective but the problem was in this case are getting so many contradicted information summit contradicting information that they they ignored the stick shaker is of all of all things I ignore them and it was and he then goes on to say possibly because of the compelling evidence from the airspeed indicator of course the problem was the SP indicator was indicating correctly either so you for ages ago in a safe eight as they believe they had control problems rather than instrument problems because their actions weren't reflected by the instrumentation readings and for a while they had on autopilot which was of course was using incorrect data as its parameters so the control tower was actually getting altitude data from the plane and speed data from the radar so this is one of the things people don't realise is that there is actually a connection in between planes and aircraft towers that where the aircraft hours can actually get information from the computers on board the plane so and they can cross-reference information against radar readings so anyway are long story short the ultimate was reading 9700 fees and that's just been confirmed by air traffic controller what they were doing was they were comparing the value that they were erroneously getting from that the aircraft rather than from the radar which meant that they were essentially reading back the value that they soil here we confirm that in realise possibly be read telling their playback yes and we actually have you at the wrong altitude for really really don't know should really check anything artistry anymore offal yes this is orthotist actually awful see all these things are added up is crazy and terrible anyway the overspeed warning ago continues the overspeed warning was still sounding along with two low terrain and if you watch the reenactments are in the thing it was the air crash investigation and in the reenactment when they remap part of this the of the CVR transcript the list you heard the alarm going off to low terrain to low terrain to low terrain and it's like these pilots try to you what the hell is going on I can't see anything and of course you know at which point you know I hit the water at 300 miles an hour and it's all over so I have to say are a big very big thank you to our Dean for that and some he had a lot more than information are for me and it was some was it was great to re-our get the feedback from someone who is who is who is into that and also has an interest in it I haven't got so far as to buy the book bits are honestly if you are interested in this sort of thing then there is there are books out there not just this particular one is this several of them and are I think a lot of them are done by the same the same guy are Malcolm MacPherson I think is her several books I believe on the subject so why are I think that some that this is an interesting addendum to the to the yard to the episode so thank you very much that feedback and that's all I had´┐Ż
Duration 5 minutes and 36 seconds Direct Download

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Ben Alexander

Ben Alexander

Ben created and runs and Fiat Lux

John Chidgey

John Chidgey

John is an Electrical, Instrumentation and Control Systems Engineer, software developer, podcaster, vocal actor and runs TechDistortion and the Engineered Network. John is a Chartered Professional Engineer in both Electrical Engineering and Information, Telecommunications and Electronics Engineering (ITEE) and a semi-regular conference speaker.

John has produced and appeared on many podcasts including Pragmatic and Causality and is available for hire for Vocal Acting or advertising. He has experience and interest in HMI Design, Alarm Management, Cyber-security and Root Cause Analysis.

You can find him on the Fediverse and on Twitter.