ditchman Posted March 20, 2019 Report Share Posted March 20, 2019 (edited) Just heard on the news ...almost a throw-a-way comment...........first reports must be coming from the black box thingy recorder "moments before the Boeing crashed...the crew were frantically searching the manuals, to disable the computor...to stop the aircraft from diving" that is just so awful.....such a preventable accident.................why isnt there some sort of chicken switch....on such a complicated piece of equipment why is there such a reliance on computors.....i know on some military aircraft if the computor failed the plane would just drop out of the sky....... im not anti technology...........but i think that is so wrong... i suppose you could say the same about F1.......at least on modern cars they go into limp home mode...and the steering and brakes still work.. Edited March 20, 2019 by ditchman Quote Link to comment Share on other sites More sharing options...
walshie Posted March 20, 2019 Report Share Posted March 20, 2019 They suspected something like that before it happened. There's an angle of attack sensor on the wing apparently and if it senses the plane is climbing too steeply it drops the nose to stop it stalling. As you say, there should be a manual override because we all know computers can and do go wrong. Quote Link to comment Share on other sites More sharing options...
chrisjpainter Posted March 20, 2019 Report Share Posted March 20, 2019 4 minutes ago, walshie said: They suspected something like that before it happened. There's an angle of attack sensor on the wing apparently and if it senses the plane is climbing too steeply it drops the nose to stop it stalling. As you say, there should be a manual override because we all know computers can and do go wrong. Yup. This new 737 Max-8 has two sensors that are designed to do just that, one on each side. There is manual override, but it's not just the flick of a switch. Radio 4 had a chap from a company that specialises in plane crash analysis, who said having just two sensors is far too few to be responsible for something so serious as wing angle. There was also meant to be a software update that came in after that first crash. If it was done on this aircraft, it clearly had no effect. Quote Link to comment Share on other sites More sharing options...
figgy Posted March 21, 2019 Report Share Posted March 21, 2019 Ditchy modern fighter aircraft couldn't fly without computers. The most skilled pilots couldn't put enough input to fly them. At least they have ejection to call on should the worst happen. Quote Link to comment Share on other sites More sharing options...
TIGHTCHOKE Posted March 21, 2019 Report Share Posted March 21, 2019 (edited) Both of the 737 Max crashes seem to have a similar problem, aircraft diving under computer control, last week there was a story going round that the auto-pilot had not been tested fully. Many years ago one of the Airbus development aircraft crashed while landing under computer control and the aircrew were unable to over-ride/disengage the computers and return to human controlled flight. There are loads of items available on the internet that detail some of the problems. Edited March 21, 2019 by TIGHTCHOKE Additional information. Quote Link to comment Share on other sites More sharing options...
oowee Posted March 21, 2019 Report Share Posted March 21, 2019 Insufficient training on the over ride system. There was a pilot on radio a couple of weeks back talking about how they rehearsed the over ride procedure before each flight. Looks like there has also been a software update too. Quote Link to comment Share on other sites More sharing options...
JohnfromUK Posted March 21, 2019 Report Share Posted March 21, 2019 8 minutes ago, oowee said: Looks like there has also been a software update too. I thought they were still working on a software update (one of the reasons given for the 'grounding" order). Perhaps there has been one update - and another in the pipeline? Testing and 'proving' updates is very difficult - as you have to be 100% sure there are no 'side effects'. Quote Link to comment Share on other sites More sharing options...
Raja Clavata Posted March 21, 2019 Report Share Posted March 21, 2019 My understanding is that although there are two sensors the system is currently configured to respond to either sensor indicating a stall condition so if one indicates a stall erroneously the "corrective" action is initiated as a kind of fail safe. Stall sensors have always been problematic particularly from a product liability perspective, even those that do not involve software. The issue here does appear to be the software and the lack of training / awareness of the feature by relatively inexperienced crews. The software patch is long coming and delayed apparently due to the US government being shut down by the Trump administration. Quote Link to comment Share on other sites More sharing options...
TIGHTCHOKE Posted March 21, 2019 Report Share Posted March 21, 2019 2 minutes ago, Raja Clavata said: My understanding is that although there are two sensors the system is currently configured to respond to either sensor indicating a stall condition so if one indicates a stall erroneously the "corrective" action is initiated as a kind of fail safe. Stall sensors have always been problematic particularly from a product liability perspective, even those that do not involve software. The issue here does appear to be the software and the lack of training / awareness of the feature by relatively inexperienced crews. The software patch is long coming and delayed apparently due to the US government being shut down by the Trump administration. Yes indeed, BUT the stall sensors should be an advisory tool for the aircrew, not a problem that they cannot over-ride. Quote Link to comment Share on other sites More sharing options...
MirokuMK70 Posted March 21, 2019 Report Share Posted March 21, 2019 I think its fair to assume that boeing will be facing some hefty lawsuits from the families of every person on those 2 planes.... Quote Link to comment Share on other sites More sharing options...
Raja Clavata Posted March 21, 2019 Report Share Posted March 21, 2019 24 minutes ago, TIGHTCHOKE said: Yes indeed, BUT the stall sensors should be an advisory tool for the aircrew, not a problem that they cannot over-ride. Agreed, that has always been the case traditionally but I believe the new MCAS system is supposed to be autonomous albeit with manual over-ride (seemingly poorly documented). There is a history of actual stall and / or false stall indications leading to incidents like the Air France 447 flight in 2009 where operator error is attributed to the accident. There is also this "paradox of autonomy" where the use of highly automated systems leads to the dumbing down of the operator. This will be a key factor in "self driving" cars too. I'm in no way sticking up for Boeing or pointing the finger at the aircrews of both these ill-fated flights, it's just as sad chain of events that led to horrific loss of life (twice!). Quote Link to comment Share on other sites More sharing options...
chrisjpainter Posted April 4, 2019 Report Share Posted April 4, 2019 Update: It seems that the pilots did everything they should have done - including the stuff recommended by Boeing, but still the plane refused to come out of nosedive. I wonder where that leaves Boeing. https://www.bbc.co.uk/news/business-47812225 Quote Link to comment Share on other sites More sharing options...
Raja Clavata Posted April 4, 2019 Report Share Posted April 4, 2019 Just now, chrisjpainter said: Update: I wonder where that leaves Boeing. https://www.bbc.co.uk/news/business-47812225 Responsible for 346 deaths I'd say, what a complete farce. Quote Link to comment Share on other sites More sharing options...
TIGHTCHOKE Posted April 4, 2019 Report Share Posted April 4, 2019 3 minutes ago, chrisjpainter said: Update: It seems that the pilots did everything they should have done - including the stuff recommended by Boeing, but still the plane refused to come out of nosedive. I wonder where that leaves Boeing. https://www.bbc.co.uk/news/business-47812225 liable and getting their IT experts to re-write a lot of programming! Quote Link to comment Share on other sites More sharing options...
Raja Clavata Posted April 4, 2019 Report Share Posted April 4, 2019 1 hour ago, TIGHTCHOKE said: liable and getting their IT experts to re-write a lot of programming! It will be interesting to find out what language this software was implemented in Quote Link to comment Share on other sites More sharing options...
TIGHTCHOKE Posted April 4, 2019 Report Share Posted April 4, 2019 Well, either the airframe didn't recognise the commands, the computers didn't issue the correct commands or the autopilot/anti-collision system had no way of being over-ridden by the chaps at the pointy end. Quote Link to comment Share on other sites More sharing options...
Raja Clavata Posted April 4, 2019 Report Share Posted April 4, 2019 28 minutes ago, TIGHTCHOKE said: Well, either the airframe didn't recognise the commands, the computers didn't issue the correct commands or the autopilot/anti-collision system had no way of being over-ridden by the chaps at the pointy end. Indeed but at a lower level I would not be surprised if this doesn't turn out to be an interface issue brought about by this feature being bolted on rather than designed into the overall architecture of the aircraft. I suspect the software language may be C++ but we'll probably never get to know, at least officially. Quote Link to comment Share on other sites More sharing options...
TIGHTCHOKE Posted April 4, 2019 Report Share Posted April 4, 2019 Fair enough. Unlikely to be flying until it is properly addressed. Quote Link to comment Share on other sites More sharing options...
Raja Clavata Posted April 4, 2019 Report Share Posted April 4, 2019 I should caveat what I just said on the basis that it's not proven to be a fundamental design issue in the system, I'm surprised there are only two sensors as normally there would be triple redundancy in a system like this but they may well have it covered. Just now, TIGHTCHOKE said: Unlikely to be flying until it is properly addressed. I wouldn't have got on a 737 MAX after the last crash but since all the affected aircraft are grounded globally I don't think you should be any more concerned about flying than usual. Quote Link to comment Share on other sites More sharing options...
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