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EightBit posted:I know that airline pilots are trained to trust their instruments over their senses, but if you're flying at night at FL400, aren't you above clouds? Can't you loving see that you have the nose pointed way up? AF447 was in a storm weren't they?
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Jan 27, 2014 06:06
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Bob A Feet posted:Yeah, the pilots in AF447 probably could've done that, but the time they had to trouble shoot was minimal (The article said they struck the water at something like -11k fpm). The rush of trouble shooting the problem combined with the lack of stall warning that they were used to probably meant they didn't realize they had the nose up so far. Not to mention it was trimmed up in that position so they may not have felt the control pressure (or whatever artificial system it uses) to keep it there. Hang on, did the autopilot pitch the aircraft nose-up and stall itself automatically before the crew could figure out what the gently caress or did the aircraft give a stall warning and the crew "corrective" action hosed the plane? As in, if the crew ignored the alarms, would the plane have continued to fly straight and level? "ohfuckohfuckohfuck we've got no airspeed and the nose has just dropped by 30 degrees" "tell the CVR you love your kids" or "ohfuckohfuckohfuck we've got no airspeed" "hang on, throttles haven't moved, engines are working fine and attitude is unchanged" "fuckit, just pull the breaker on the alarm and we'll fly using the GPS" EightBit posted:I know that airline pilots are trained to trust their instruments over their senses, but if you're flying at night at FL400, aren't you above clouds? Can't you loving see that you have the nose pointed way up? I think it would still be very hard to see the horizon if you've only got starlight to guide you. I'd guess even the cockpit lights would be enough to prevent you seeing the horizon and it would have to be completely blacked out for a solid 20 minutes to have even a remote chance of VFR-ing at night. I've never tried it though. Captain Postal fucked around with this message at 06:19 on Jan 27, 2014 |
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Jan 27, 2014 06:16
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None of the above, the autopilot disconnected when the airspeed indication wasn't working and then the pilots put the plane nose up while trying to compensate for turbulence, stalling it. The loss of the airspeed indicator made the stall warning somewhat intermittent and the plane was in "alternate law" mode changing the handling characteristics and losing the stall prevention. Furthermore counter-intuitively the stall warning would go off when the pilot would pull back on the stick instead of pressing it forward as the angle of attack would affect if the computer determined the sensor data to be valid, etc. http://en.wikipedia.org/wiki/Air_France_Flight_447 It's frustrating reading after the fact knowing that different actions could have led to a very different outcome, but, sadly, what happened has happened and can't be changed.
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Jan 27, 2014 06:40
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If impact was around -1100fps, I'm sure there's an overload of poo poo going on to pay attention to, but someone's stomach has to be doing somersaults and/or a bottle of water on the flight deck is a pretty steep angle.
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Jan 27, 2014 07:29
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SeaborneClink posted:If impact was around -1100fps, I'm sure there's an overload of poo poo going on to pay attention to, but someone's stomach has to be doing somersaults and/or a bottle of water on the flight deck is a pretty steep angle. New FAR25 reg: all aircraft must have a $2.50 2-axis spirit level in the cockpit. Buy one from the terminal camera store 
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Jan 27, 2014 07:38
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EightBit posted:I know that airline pilots are trained to trust their instruments over their senses, but if you're flying at night at FL400, aren't you above clouds? Can't you loving see that you have the nose pointed way up? From what I saw there was nothing wrong with attitude reading. The pitot may have iced and screwed up airspeed, but the plane was reporting it's nose up attitude the whole time. What gets me here is the sidestick configuration and unlike the yokes in a Boeing that you can see and feel your copilot has pulled back on, you've got no idea what your buddy is doing. It's like the whole time the three of them are talking, increasingly frantically, about what the gently caress is going on and why is the plane stalling while one guy is pulling back on the stick while he's talking to the others about it.. and noone knows. Then you get that janky way the stall warning worked, that because it was getting bad data when the pilot took his hand off the sidestick the stall warning would come on, when he'd pull back the computer would decide the data was bad and the stall warning would stop. Which may have been interpreted as you're correcting the stall by going nose up, but when in any aircraft do you point the nose up to correct a stall? Isn't there multiple ways to get airspeed? There is a pitot on each side, right, one feeds into copilot controls and one into pilot. Was there no way to ascertain airspeed, once you've decided you're getting some bad data and that combined with altitude (which was working) and attitude tells you you're falling? Tony Montana fucked around with this message at 10:12 on Jan 27, 2014 |
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Jan 27, 2014 10:08
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Tony Montana posted:From what I saw there was nothing wrong with attitude reading. The pitot may have iced and screwed up airspeed, but the plane was reporting it's nose up attitude the whole time. What gets me here is the sidestick configuration and unlike the yokes in a Boeing that you can see and feel your copilot has pulled back on, you've got no idea what your buddy is doing. I agree with you about the stall warning BUT: I'd speculate that it comes down to technological limitations when the aircraft was designed. You have an angle of attack sensor that will send an input into your stall warning system, but at some point, because it's a mechanical sensor and can break or get jammed or just stop working, it needs to say "I am out of range of normal operation, disregard my input". I just don't think the software engineering was there with the ifs and ands to say if you are reporting beyond normal operating range, I still want to know what you are reading, compare it with everything else, and decide whether that beyond normal is actually valid, and if you are reporting intermittently, I will model your reading based on your previous rates and scales of movement to determine actual angle of attack. I don't even think modern software is up to the task. As for airspeed, you've got 3 pitot sources, 1,2, and standby. If they're all iced up, you've got no airspeed data. You'd probably also have an ice detection message, which should clue you in "hey, we're iced up, and we have no airspeed, maybe the pitots are iced up too". Again this is pure speculation, but I just don't think a lot of transport pilots these days in a lot of countries cut their teeth flying dodgy old poo poo where iced pitots, water filled pitots, and and general air data sketchiness is more a possibility. They might do a few 'loss of airspeed' scenarios in the sim, and then spend 2000 hours flying their modern reliable aircraft with absolutely nothing going wrong. I don't think a lot of pilots out there actually have the experience to know what a loss of air data actually manifests as.
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Jan 27, 2014 10:46
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At the time of the accident, Airbus was already working on a way for crews to cope with full loss of air data. This is what it looks like:  It uses GPS and intertial data only to provide the crew with altitude and AOA data, and was first introduced in the A380. Unfortunately, it arrived too late to prevent AF447. Tony Montana knows what's up: the sad fact is that in a B777 with conventional yokes and no autotrim it probably wouldn't have happened. e:Better image Linedance posted:
Tsuru fucked around with this message at 11:03 on Jan 27, 2014 |
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Jan 27, 2014 10:47
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Tsuru posted:At the time of the accident, Airbus was already working on a way for crews to cope with full loss of air data. You know, this is always implied with that incident, and while I don't disagree, I don't wholly agree either. In the Boeing, you'd still need the pilot-not-flying to notice, with everything else going on, that his stick has moved back slightly, and then attribute it to the other pilot (why would the other pilot be pulling back on the stick? That doesn't make sense. It must just be *yet another aircraft variable in this complex scenario*), and then question the pilot flying whether he is pulling back on the stick and if that is appropriate. Of course in a perfect world it would work like that, but in a perfect world they would have been well rested and alert, and wouldn't have chosen to fly through the supercell to save a few minutes and a few hundred kilos of fuel either.
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Jan 27, 2014 11:01
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I'm not discounting overload, I'm certainly not trying to armchair fly and said they should have done this or that. It just says on Wiki they had 20k hours of experience on that flight deck between them. When you're unable to use the autopilot because it's disengaged and you're flying by hand, we think we are in a stall condition, I would have though in a Boeing someone would have said 'hey, you're pulling back on the stick!'
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Jan 27, 2014 11:05
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Linedance posted:You know, this is always implied with that incident, and while I don't disagree, I don't wholly agree either. In the Boeing, you'd still need the pilot-not-flying to notice, with everything else going on, that his stick has moved back slightly, and then attribute it to the other pilot (why would the other pilot be pulling back on the stick? That doesn't make sense. It must just be *yet another aircraft variable in this complex scenario*), and then question the pilot flying whether he is pulling back on the stick and if that is appropriate. Of course in a perfect world it would work like that, but in a perfect world they would have been well rested and alert, and wouldn't have chosen to fly through the supercell to save a few minutes and a few hundred kilos of fuel either. Tsuru fucked around with this message at 11:11 on Jan 27, 2014 |
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Jan 27, 2014 11:07
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Tony Montana posted:It just says on Wiki they had 20k hours of experience on that flight deck between them. it actually says the senior pilot (who was asleep in the crew rest) had 11k hours, 1.5k on type, and the two pilots in the flight deck at the have 9k hours between them, without specifying how much on type. I'd guess it's less than 1000 hours on type each, and it wouldn't surprise me if it was less than 500 hours. Even if they'd spent 4500 hours each flying exclusively Airbus products, I doubt they would have ever encountered anything like this scenario before, and probably have only ever seen Alternate Law and Direct Law in the sim.
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Jan 27, 2014 11:12
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Tsuru posted:One of the things that happened to AF447 and which I already briefly alluded to in this very thread, is that the autotrim system trimmed the THS fully up because the PF kept pulling up. With the rearward cruise CG and alternate law still being active, this created an aircraft which appeared statically and dynamically stable ("feels normal") in pitch at extreme AOA. The 777 and 787 can't do this, since 1) it would require manual input to the trim switches and 2) they won't allow you to move the trim speed below a certain value. I can see why each company does it their way, but I have to agree that the Boeing implementation (manual trim for manual flight) is the better option. You can look at stab trim as a sort of pilot convenience, but whereas in Airbus, pilot convenience means "here, let me do that for you", in Boeing this particular pilot convenience means "we put the trim switches next to your thumb so you don't have to reach anywhere". Having big black and white stripy wheels in the Airbus that move to let you know your stab is trimming seems like it should be enough, but I'm not a pilot and I can see how it could be confusing, when they're always moving when trimming, to make that leap to question "hang on, why is the stab trimming now?"
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Jan 27, 2014 11:40
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ausgezeichnet posted:Falcon 7x Stuff I forgot to say thanks for the information. Thanks. I'll probably never fly on a business jet of any kind, but that doesn't keep me from drooling over them.
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Jan 27, 2014 12:03
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ausgezeichnet posted:The rich guy I fly for has had about enough of the reliability problems and recently put a deposit down on a Gulfstream 650. I find this a little hard to comprehend. I was having diner with a former Asia pacific Airbus sales manager and he told me about a conversation he had at a cocktail function. He met a business man and they got to talk about planes and the business man said in passing that he had a G-V and a Citation-X and was looking to buy something newer, so this sales director was thinking $$$, and "this should be an easy sell". I mean, the business man could have bought an A320 business jet for the same price as the G-V, the A320 is much larger on the inside, much more luxurious, more head room, longer range, more payload... it's better in every measurable way (except fuel price, but if you own TWO business jets, you probably don't give a gently caress about the cost of fuel), but this business man absolutely refused to consider the A320 or BBJ, simply because he was worried that when he took off or came in to land, someone driving past on the highway might confuse his flying palace for a Ryan Air flight... This customer attitude is the major motivator driving sales for the BizJet market, and what keeps them in production God the things I would do to have that sort of money to throw around. Captain Postal fucked around with this message at 12:23 on Jan 27, 2014 |
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Jan 27, 2014 12:19
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Not that long ago a friend that is a flight instructor was in my car, we were going past the airport and he said 'duck in here, I wanna show you something'. Weaved around and through some gates and eventually to a hanger, inched back the door and inside was a brand new, freshly painted Learjet. I'd seen them before and we all know what they look like, but it being right there and looking so new.. it was one of the most beautiful things I've ever seen in my life and it inspired silent homage. \/\/\/ edit: the iced pitot kicked them into alternate law, meaning the plane will now accept inputs that will kill it. The ice cleared within 30 seconds, but here is where things get really scary as it's lack of understanding the systems. The computer when sensing AOA is extreme (nose up like gently caress) will consider it's airspeed data invalid (because the plane isn't supposed to climb like that) and not issue stall warnings. So when he took his hand off, the AOA would sometimes drop below the extreme level in the computer and the computer would look at it's data and issue the stall warning. I guess because that's what made it go away last time, he'd pull back again and the warning would stop because the computer would go over it's AOA threshold again. It all started with a sharp yank back on the stick when the autopilot went off at the start, while he rolled the craft left and right and he was getting used to manually flying it. So yeah, from 35,000 there is nothing wrong with the plane, engines are 100% and 40 degrees AOA. Airspeed would have told you that you're certainly not climbing an the altimeter would have confirmed you're falling. You push the stick forward and that would have been it. That's why I was talking about experience on the flight deck, they knew this and stress/overload/brainfart somehow clouded the judgement. With a connected control column and two pilots with it right in front of them, perhaps that would have triggered one to question the inputs. Tony Montana fucked around with this message at 13:04 on Jan 27, 2014 |
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Jan 27, 2014 12:22
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Linedance posted:You know, this is always implied with that incident, and while I don't disagree, I don't wholly agree either. In the Boeing, you'd still need the pilot-not-flying to notice, The AB PIC pulled the stick all the way back because he had confidence that the FCS wouldn't allow him to stall. And it wouldn't, in normal law, because Airbus reasons. But because of the faulty airspeed data, the FCS reverted to alternate law, which does allow the pilot to stall the airplane, and he failed to recognize that and didn't know how to fly an airplane at high altitude so he ignored the repeated stall warnings and killed everyone by being a dumbshit. The ice in the pitot cleared. He was getting good airspeed data. Because of a momentary fault, he flew a perfectly functioning airplane into the loving ocean. You can talk about specific UI decisions all day long but a combination of UI and training that leads a pilot to believe "These stall warnings and stick-shakers that are going off are all bullshit, I *have* this motherfucker" is Dumb. The captain, who'd been napping at the back, gets back into the cockpit before they hit and Dumbass says something to the effect of "I don't know what's going on, I've been pulling the stick back all the way this entire time and we're still losing altitude." Captain basically facepalms right before they impact. Phanatic fucked around with this message at 12:30 on Jan 27, 2014 |
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Jan 27, 2014 12:28
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Came closer than I would have liked to a stall due to pitot icing in IMC, scared the poo poo out of me. edit: no story and no opinion on those Air France guys, just wanted to add that that poo poo is terrifying
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Jan 27, 2014 13:51
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So, I'm going to avoid flying in an Airbus any time soon.
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Jan 27, 2014 14:13
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Going off probability of a crash vice a normal, successful flight, you'd probably be better off just avoiding Air France, and even then the odds of it mattering are somewhere in the win-the-lottery range.
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Jan 27, 2014 14:15
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Speaking of crashes, I'm a sucker for Mayday (aka Air Crash Investigation). Not having anything beyond an interest in aviation, how does it rate in accuracy?
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Jan 27, 2014 14:29
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Illuminati by Nature posted:Speaking of crashes, I'm a sucker for Mayday (aka Air Crash Investigation). Not having anything beyond an interest in aviation, how does it rate in accuracy? I love it, but it's got to be the UK version and not the US. Can't handle the US announcer and that 'repeat the same thing over and over every 30 seconds' that US shows do a lot of. They way over sensationalize as well. The UK one is a straight up doco, so you can go and check the records of what they're reporting on and it all lines up.
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Jan 27, 2014 14:47
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A tigermoth had to make an emergency landing on a beach south of Melbourne this afternoon. Public holiday too, so pretty busy beach from the sounds of it. There is a video in the link: http://au.news.yahoo.com/a/21090301/bi-plane-lands-on-barwon-heads-beach/ quote:Holiday makers have run for safety when a vintage bi-plane made an emergency landing on a crowded beach at Barwon Heads.
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Jan 27, 2014 14:51
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Snowdens Secret posted:Going off probability of a crash vice a normal, successful flight, you'd probably be better off just avoiding Air France, and even then the odds of it mattering are somewhere in the win-the-lottery range. Just avoid air france anyways.
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Jan 27, 2014 15:05
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Please Fly On Boeing Airplanes, at least until I get a new job
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Jan 27, 2014 16:48
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EightBit posted:So, I'm going to avoid flying in an Airbus any time soon. Will you be avoiding automobiles too?
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Jan 27, 2014 18:22
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I'm about to board an A320 for a 5.5 hour flight! If I notice any unusual attitudes I'll be sure to ring my FA button. Also, the captain better leave channel 9 on.
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Jan 27, 2014 18:25
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Cocoa Crispies posted:Will you be avoiding automobiles too? I guess AF447 is kinda the airplane equivalent of the accelerator getting stuck on the floor mat of your Camry.
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Jan 27, 2014 18:32
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hobbesmaster posted:I guess AF447 is kinda the airplane equivalent of the accelerator getting stuck on the floor mat of your Camry. I bought a 2012 Camry and holy poo poo was Toyota ever eager for me to understand that if I used non-OEM floor mats I would do so at my own risk, that doing so might cause the car to suddenly speed up on its own and explode and... Like seriously, I think I had to sign two forms, it's in the owner's manual and I think they sent me a letter to remind me afterward. Seriously, you'd think there was an epidemic of out-of-control Toyotas roaming the world's roads, what the gently caress. Does anyone have Airbus vs Boeing accident rate comparisons?
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Jan 27, 2014 18:37
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FrozenVent posted:Does anyone have Airbus vs Boeing accident rate comparisons? I'd imagine it'd be skewed quite a bit by Boeing existing way before Airbus. Even if you do "post-1974 accident rate" there's a lot of older planes and you have to decide if you want to exclude all cases of "pilot error" or not. In any case I'd imagine it'd really come down to "what was flown by the most incompetent airlines".
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Jan 27, 2014 18:54
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wdarkk posted:I'd imagine it'd be skewed quite a bit by Boeing existing way before Airbus. Even if you do "post-1974 accident rate" there's a lot of older planes and you have to decide if you want to exclude all cases of "pilot error" or not. This. Plus the fact that there are a lot more Boeings in the air than Airbus at any given time. What you really need is "System failure resulting in incident per 1000 flight hours of aircraft built after 19XX" to make an apples to apples comparison and I think Airbus would have a marginal number more.
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Jan 27, 2014 19:10
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kmcormick9 posted:What you really need is "System failure resulting in incident per 1000 flight hours of aircraft built after 19XX" to make an apples to apples comparison and I think Airbus would have a marginal number more. Yeah that's what I meant by accident rate - Incidents per xxx hours of operations, since Y date. I know Canada's TSB keeps them for every modes, but I don't think they segregate (publicly anyway) by equipment used.
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Jan 27, 2014 19:12
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FrozenVent posted:Yeah that's what I meant by accident rate - Incidents per xxx hours of operations, since Y date. How do you determine if the incident is the fault of the aircraft design and not the airline being a piece of poo poo and cheaping out on maintenance?
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Jan 27, 2014 19:36
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wdarkk posted:How do you determine if the incident is the fault of the aircraft design and not the airline being a piece of poo poo and cheaping out on maintenance? That's something usually specified in the NSTB (or equivalent) report I'd imagine
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Jan 27, 2014 19:53
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wdarkk posted:How do you determine if the incident is the fault of the aircraft design and not the airline being a piece of poo poo and cheaping out on maintenance? Its very rarely either of those by themselves.. Its usually those things, maintenance or aircraft in a very minor sense, that are accented by the pilot making an error. When the planets line up, bad things can possibly happen.
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Jan 27, 2014 20:22
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American 191 and Alaska 261 are both heartbreaking examples of solely bad maintenance causing a crash.
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Jan 27, 2014 21:18
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Did you all know there is a ton of Air Crash on YouTube? Here is a stack of Season 13, 2013 and they're making another this year (because it's awesome). http://www.youtube.com/playlist?list=PL6-_b3CUyj442TOu8AvI88aI4DY3DxcHw There is heaps more too, from other uploaders 
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Jan 27, 2014 21:34
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So, I'm going to the Netherlands with my band the first week of February and it's my first trip overseas. I'm flying Delta out of DTW and they're putting us on an A330, which'll be my first Airbus. I'm pretty stoked, mostly because I'm easily impressed.
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Jan 27, 2014 21:42
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It's pretty fun - I expect the first few hours of your flight you'll be having a great time. Did you get a window seat? You can learn first-hand how oceans are, in fact, enormous! I've flown Delta intercontinental but I think it was all 747/767. Still, I expect the same advice applies: If you're tall, spring for the legroom upgrade if you can (or the first/business if you're made of money) - it made my oceanic flight tolerable instead of hateful hell death. The significant number of Robert Downey Jr movies on the IFE made it better. ps: if you end up in first/business don't  Psion fucked around with this message at 22:12 on Jan 27, 2014 |
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Jan 27, 2014 21:52
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CroatianAlzheimers posted:So, I'm going to the Netherlands with my band the first week of February and it's my first trip overseas. I'm flying Delta out of DTW and they're putting us on an A330, which'll be my first Airbus. I'm pretty stoked, mostly because I'm easily impressed. Where are you guys playing?
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Jan 27, 2014 22:00
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