|
reply to Count Niemantznarr:
yes whilst in testing recovery by an experienced test pilot can be done but in practise a number of tridents and other aircraft have been lost in a `super stall`; ASN Aircraft accident Hawker Siddeley HS-121 Trident 1C G-ARPY Felthorpe ASN Aircraft accident Hawker Siddeley HS-121 Trident 1C G-ARPI Staines ASN Aircraft accident Canadair CRJ100 (CL-600-2B19) C-FCRJ Byers, KS |
I agree we've gone as far as we can with what we know.However,training issues havent really surfaced.Full stalls are trained in flight school.In airlines,only the approach to stall is trained and minimum altitude loss is always emphasized.This might lead to a dangerous mindset for newish pilots;the altitude loss is as important as recovery.Significant altitude loss is a dead cert at altitude.High altitude upset recovery also rarely trained.Other training issues that I can think of;crews anxiety over busting altitude when facing speed loss at altitude.Crews have been known to wait for ATC clearance before descending.Turn off airway and DESCEND IMMEDIATELY.The use of weather radar has been addressed but they knew there was weather up ahead.Tilt,gain and brightness control are possible traps.Captain's rest already discussed.
Combine the gaps in training with airline-endorsed automation reliance and the peculiarities of the Airbus and you have enough ammunition to establish a strong case for pilot error with strong and genuine mitigating circs. |
Rananim:
Turn off airway and DESCEND IMMEDIATELY Although the turn off airway is the ICAO method, in this case it could have resulted in increased disorientation. Wings level was critical until a safe, stable configuration was assured. |
The BEA report tell us that the THS remained at 13% nose up including during the nose down stick input The Perpignan A320 report says something quite critical - the THS only moves once the elevators are driven beyond neutral. It's not enough just to push the stick forward, the elevators have to go past the neutral setting. I don't know if the A330 works the same way. But that would explain why the THS stayed put despite nose-down stick. |
Too much to read but if all else fails turn all ADIRS off. Make direct law happen and fly it like a cessna. Stick forward and centered. Fulll power. Wings level and recover. Otherwise 80%and 2.5 nose up. Airline industry no training for UAs or chamber (depress) runs. What a joke. Don't be near rec max (coffin corner). And go around the weather. 100 mm plus who gives a !!!!. ATC are advisory only. Do what you need too do. No one one on the ground will save you. You are the pilot. If not, get out of the cockpit and let the big bIg boys (well trained ie Sully) do it for you. The moral of the story is don't fly into thumderstorms! Any questions?
One hint Power plus Attitude equals performance. Descend and get some CLs |
....but the VC10's were frequently flown at 43,000 feet with a little help from the droops.... I look forward to some sane comments once the report has been fully released. Meanwhile, I hope that pilots will be encouraged to learn more about their aeroplanes and systems rather than becoming dumbed-down auto flight system and ECAM monitors. |
Too much to read but if all else fails turn all ADIRS off. Make direct law happen and fly it like a cessna. Stick forward and centered. Fulll power. Wings level and recover. Otherwise 80%and 2.5 nose up. Airline industry no training for UAs or chamber (depress) runs. What a joke. Don't be near rec max (coffin corner). And go around the weather. 100 mm plus who gives a !!!!. ATC are advisory only. Do what you need too do. No one one on the ground will save you. You are the pilot. If not, get out of the cockpit and let the big bIg boys (well trained ie Sully) do it for you. The moral of the story is don't fly into thumderstorms! Any questions? I agree with your solutions, but I would point out that civilian airline pilots trained in the 50s, 60s, 70s, and possibly 80s, were trained well. They had 'airmanship'. I have flown with many ex-forces pilots who were bordering on useless. I think some of them had only kept their jobs because they were, in UK parlance, 'civil servants'. Please don't presume to be superior - you (possibly) are not.:) |
Hi, MRGTC, I got my training in the military. If I may ...
Too much to read but if all else fails turn all ADIRS off. Make direct law happen and fly it like a cessna. Stick forward and centered. Full power. Wings level and recover. Otherwise 80%and 2.5 nose up. If stalled, nose up and power may or may not get me out of it, depends on what I was doing when I stalled, and how close to critical AoA I am. I'd suggest dropping the nose, wings level, until flying again, and then adjust power and attitude to regain level flight. As to Power and attitude. You can go back to this crash, the discussions on this forum, since about 02 June 2009, and find "fly power and attitude" as advice being the running refrain from the Greek Chorus. Descend and get some CLs In the military, they taught us that you go over, around, or through the bottom third of (If you had no way out and could not find a place to land) thunderstorms. Descending into one when way up in the sky ... no, they didn't teach us, and I am pretty sure they didn't teach you that. Cheers. |
BEagle. Do some research or at least speak to a military VC10 driver ........ |
Deliberate partial panel not much fun without a turn indicator......
|
captainsmiffy:
Reminds me of an old Monty Python sketch "No, not much fun in Stalingrad." No, not much fun in the goo, in and around CBs in partial panel, or worse ... :uhoh: |
I have followed this thread from the start and some posts suggest that the problem with AF447 (and in many other incidents) may have been caused by an ice blocked pitot-tube. But my question is, Airbus must clearly have tested what a blocked pitot tube would tell the computers to do at that flight level and with that speed? Why is it that I always get the feeling that the FBW software always freaks out when the tubes are blocked and putting the crew in "what the heck is it doing now" mode. There have been so many incidents and crashes in the past by this IAS measuring device so I cannot understand why this still is a problem?
I know that IAS and GroundSpeed are totally different things as the aircraft can be flying in heavy headwind etc, but getting an indication of a sudden drop in IAS from 275 kt to 60 kt must definately be verifiable with GPS data in combination of the known headwind prior to the drop and in that way give the pilots a reading that they have NOT lost the speeds. There must be another way to measure the aircraft's speed through the wind than just putting the trust in 3 heated tubes that seem to clog more often that wanted. |
Full backstick & full power almost all the way down.
Is it possible that all the PF saw was the altimeter unwinding at a rapid rate & held full back stick & full power to recover, saying to himself that the computer won't let the aircraft stall? Isn't that the EGPWS & windshear recovery technique as well? |
QF72 style ADIRU failure = nose up
The QF72 incident and the earlier QF71 could have been fresh in the minds of the AF447 crew. I recall that the QF72 ADIRU fail caused false warnings of over speed, stall, underspeed, AoA. The QF72 A330 was cruising at mid day in good weather and the erronous flight instrument readings and warnings were immediately obvious and corrected.
As noted by the BEA there were some significant differences between the computer fail of AF447 and QF72. However there was some overlap in symptoms. The point is that ADIRU malfunction should have been a known issue to the AF crew and they presumably would have had corrective procedures. Unfortunately the ADIRU fail procedures were inappropriate/exacerbating to their true predicament of pitot icing. It would explain the counter-intuitive behaviour of the pilots apparently ignoring the flight instuments and stall warnings and pulling the nose up. |
..........No more information would reveal whatever we don't yet know, .......... I can't believe two guys would sit there and only pass the few sparse comments that have been released, knowing what they said ( if only m***de ! ) would help understand what might have been going on on their heads and why they then took the actions that they did. We are being treated as mushrooms at the moment, and vested interests may well prevail to sit on the full story,releasing only that which suits them - liability issues will be raising their ugly heads already, and it would be naive to think otherwise. But then I'm a cynic. |
The FAA Stall Recovery Procedure:
http://xa.yimg.com/kq/groups/1048360...0Procedure.pdf Addopted by Airbus Industrie (if link doesn't work, please copy past it to your browser). |
Read the latest Airbus Safety First magazine here for an extended discussion about the new stalling procedure:
http://www.ukfsc.co.uk/files/Safety%...ary%202011.pdf |
The FAA Stall Recovery Procedure: http://xa.yimg.com/kq/groups/1048360...0Procedure.pdf Addopted by Airbus Industrie |
ExSp, why don't they release more information about what they know? The CVR will explain a lot of what happened. They seem to be reluctant to release a lot of results of the CVR and FDR. Eventually I guess they will have to release it. Until then all we can do is speculate about the little released. They have it all now and probably are laughing at our speculations.
|
A pilot needs to be taught this ......? How about CONDITIONED REFLEX? :rolleyes: |
Graybeard : The flight you are referring to was operated as TW841. It was not NWA.
|
SMOC
The forum post was on 1 June. The article referenced in it is dated 1/06/11. Here is the link from #1242: #1242 (permalink) JamesT73J Join Date: Oct 2003 Location: Hampshire, UK Posts: 159 According to flight global, automatic stab trim should have been inhibited when alpha > 30 degrees - Stalled AF447 did not switch to abnormal attitude law but it was not. Finally, here is the initial text copied from the FlightGlobal article: DATE:01/06/11 SOURCE:Air Transport Intelligence news Stalled AF447 did not switch to abnormal attitude law By David Kaminski-Morrow http://aka-cdn-ns.adtech.de/apps/404...2Id5/158271971 http://adserver.adtech.de/adserv%7C3...rp=[group] Investigation into the accident sequence of Air France flight AF447 has revealed that the Airbus A330 did not enter the abnormal attitude law after it stalled, despite it |
Thanks ExLeftSeat. As a politician would say, "I misremembered; I misspoke; it happened Northwest of New York" etc. I'll go back and fix it.
|
bubbers44
...... why don't they release more information about what they know? Bet your bottom dollar lawyers and insurance assessors are keeping a close eye on it all and doubtless advising what should and what should not be released until they are ready for the full story - and with it the apportionment of blame - to be released. but then ... just as some burglars fall over and beat themselves up whilst resisting arrest, who knows exactly how much of the CVR was preserved whilst at the bottom of the Atlantic, and available when the boxes were opened ? but then I'm a cynic. |
Do you guys get to hand fly IMC at cruise flight levels or is it just too stall-prone? Just a curious question.
Ikeep wondering what I would have done. stall alarms leads to (immediate....thought never ever ever ignore this..) -same power ( ie minimum change in known cruise settings as your speed indicator has just dropped out) -a little immediate gentle nose down alteration in elevator pitch ( you would have memorised the pitch attitude and AoA in cruise before bed every night in preparation for this precise moment...)..anything to make the stall warning go quiet and get some airover the wings -wings level - and an immediate check of the autotrim setting (as it seems thats the Airbus elephant in the room if theres no elevator authority and you're nose high +++ and descending at 10,000 fpm!) sound like good initial steps to me, and .. -fly it first and foremost on meticulous instrument scan, and worry about all the alarms and noise later ( stall warning excepted of course) -gradual turn away from track and storm if one has to -dont worry about altitude loss as its the best friend you have - in fact lose 10 000 feet very gradually and you'll feel even better about the stall risk im sure I only fly a Duchess. |
Do you guys get to hand fly IMC at cruise flight levels |
or is it just too stall-prone? |
Thank you for the Information - then it must have made the sudden alteration in the situation seem all the more challenging for the poor pilots - having to hand fly in circumstances not previously familiarised , with no speed indication , in IMC/Storm conditions.
|
According to flight global, automatic stab trim should have been inhibited when alpha > 30 degrees |
Originally Posted by learner001
Tip of the iceberg...?
From pointers to drums... From dynamics to numbers... Tiny observations large outcome... When I started flying ‘digital’ I missed and preferred the ‘old’ familiar dynamic moving pointers on the Airspeed indicators and Altimeters, rather than the relatively ‘dumb’ moving number-tapes and/or drums on the flight displays. And my ‘emotion’ is not limited to Airspeed indicators and Altimeters only. Of course, as with all sort of changes, I was told that I “just have to get used to it!” OK... Fair enough... But, although I am getting more and more used to ‘flying digital’ by now, on occasion, I really sense the lack of instant dynamic ‘speed and altitude situational awareness’ that the ‘old’ analogue Airspeed indicators and Altimeters with their moving pointers will give us more or less instantly. Looking at the tapes I have to figure out: Are the changes going up or down? Moving Fast or slow? Is it an increase or a decrease? What’s the trend? Things, that I would instantly be aware of with the analogue indicators. With digital indicators, however, I need more of my brain capacity to ‘translate’ the sheer changing of numbers on the rolling tapes (or drums) into dynamics. Oh, yes... We’ve got the ‘speed trend arrow’ to sort the speed thing out... Haven’t we... But, then again, isn’t this turning the things upside down? In every new aeroplane that our company receives, even the ‘last resort’ analogue standby instruments have been replaced by a single digital display. Man tries a lot of things to improve safety. On the other hand, in my opinion, these efforts are broken down again, unnoticed. As for hindsight typing behind the computer: Most of our daily flying ends at a couple of hundred feet going out and starts again at a couple of hundred feet coming in... Almost every flight we are being flown, mostly by the comfort of automation, very near to the ‘coffin corner’... The ‘gap’ being smaller one time than the other. I wonder how many of us really actively realise this... At high altitude in the very thin air, especially in turbulence at night, a cockpit can turn into a relative ‘hell’ very abruptly if the Autopilot kicks off... (LOL most probably from many in here...) Controls will be very sloppy in conventional aircraft. In FBW aircraft this will be even more (un) noticeable, as there is different or no direct feedback. In both cases, while you’re shaking, you need to handle the controls like being a Swiss watch maker. And you are now manually manoeuvring within this tiny confined little gap... If you’re lucky you may have done it may be a couple of times. Even ‘minutes’ would do a great deal of benefit already... But it is something we hardly actually ever do...! Are we stupid, then? We train constantly for all sorts of situations... Or could here be a training deficiency? If you have/were never trained in hand flying close to the ‘edges’ of an envelope (or even outside an envelope), or if you have never actually been hand flying close to the ‘outside’ of an envelope, chances are that you won’t even notice that you’re going out... Whilst thinking you’re ‘hanging in there’... And so far, so good... How much ‘flight time’ were our unfortunate colleagues granted to log in their logbooks on actual hand flying the plane in that tiny little gap, before they all of a sudden were forced and committed to do so in a very, very narrow gap. Whilst probably shaking, vibrating and being bombarded with all sorts of alarms going off... So, whilst trying to analyse, I have learnt to always remain respectful and very humble and do a great deal of effort to see the whole picture... 29th May 2011 at 21:03. Well said Sir, well said! |
i'm not a pilot, know nothing about flying.
i'm curious to know if a large commercial airline has ever been successfully recovered from a deep stall such as occured in this case ? either in test flights, real life or even on a sim ? is it actually possible and if so what altitude would be required? i assume would require a change from tail down via wing down to nose down attitude, and that would be very tricky and unstable, risking spinning or going upside down and using up lots of altitude ?! |
i'm curious to know if a large commercial airline has ever been successfully recovered from a deep stall such as occured in this case ? The answer comes out that the denominator needs to approach zero. |
That would give you a number approaching infinity. Computers do very strange things with denominators that approach zero - like crash.
|
Okay, how about the result is unity. 1/1. Every Stall gets a recovery.
Picky kmd. ;) |
Bearfoil; AF447 didn't recover. My point was that floating point operations in computers with a finite operand length when encountering a divide by zero may do peculiar things and that the interrupt to handle that exception has to be VERY well defined. Cheers.
|
I assume would require a change from tail down via wing down to nose down attitude, and that would be very tricky and unstable, risking spinning or going upside down and using up lots of altitude ?! Best read the few thousand previous posts on all AF447 threads to catch up a bit first, then maybe post. |
I'm studying post graduate aviation medicine at present
There is a physiologic reason why pilots prefer analogue to digital readouts, and why smaller moving number images attract less attention than dials moving. The occipital cortex ( via magnocentral pathways via lateral geniculate nuclei)is hard wired to interpret visually perceived movement as potential danger without reference to "higher centres" interpeteting the visual data. ie if you saw an analogue altimeter unwinding the brain links to potential danger are more immediate, and the same would apply to the VSI in typical analogue form. When its moving tapes of numbers occuppying less visiual space and requiring more intellectual input to interpret , its natural to feel less concerned, and in fact the brain is hard wired to feel less concerned. All of this adds to increased risk at the edge of the flight envelope... |
You are right. The occipital cortex is more sensitive to peripheral field movement (millenia of evolution) compared to changes within the macular areas of the cortex. Engineers and flight deck crew are not taught that which may be why they gravitate toward digital displays until their occipital cortex clashes with their cerebellum. Whence spatial disorientation.
|
Mimpe gets an attaboy:ok:
I'm studying post graduate aviation medicine at present There is a physiologic reason why pilots prefer analogue to digital readouts, and why smaller moving number images attract less attention than dials moving. The occipital cortex ( via magnocentral pathways via lateral geniculate nuclei)is hard wired to interpret visually perceived movement as potential danger without reference to "higher centres" interpeteting the visual data. ie if you saw an analogue altimeter unwinding the brain links to potential danger are more immediate, and the same would apply to the VSI in typical analogue form. When its moving tapes of numbers occuppying less visiual space and requiring more intellectual input to interpret , its natural to feel less concerned, and in fact the brain is hard wired to feel less concerned. All of this adds to increased risk at the edge of the flight envelope... I may be one of those 'dinosaur pilots', but by gosh, I know truth when I see it. Even a moving needle on a digital display doesn't get the mental recognition and attention that the real thing gets. |
The old gravity dependent turn and bank indicator and the magnetic compass rely on forces that are difficult to manipulate by publicists or lawyers. They give you pitch, attitude and yaw but not in 3D with Hollywood star endorsements and stock options so why would anyone even look at them?
|
| All times are GMT. The time now is 22:26. |
Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.