DozyWannabe No - the PDF links contain the "at take off" and "phases after take-off" actions. It is the latter I have quoted. One does not maintain altitude by maintaining backpressure on the stick/yoke - if the aircraft is trimmed correctly then no direct input is required. Actually i think the procedure "reduce pitch" refers better to situations, where the aircraft is not entering the stall due to decaying airspeed in straight and level flight, but due to loading the aircraft while maneuvering, like initiating a turn or a climb (we called that accelerated stall). Reducing pitch (for avoiding stall) in straight and level flight would be better expressed by stick / SS push forward until stall warning stops and would cover the other situation as well. Lyman has half of my point. |
Originally Posted by RetiredF4
(Post 7447882)
You assume, that one trims into stall, therefore no backpressure is needed when speed decays? Or you are talking about an aircraft, where autotrim is keeping the aircraft trimmed into the stall?
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"DozyWannabe" - That was based on the channel 4 program.
Now I have not checked the official transcript, channel 4 translated this from French, so I do not know of the accuracy of this. I would assume they would use original transcript/translation. |
They used a combination of the BEA transcript and Otelli's from what I could tell. I watched it and must confess I can't remember words to that effect, but if I can find it on 4oD still, I'll have another look later in the week.
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DozyWannabe Because no matter how you get into the stall warning regime, pulling back is almost exclusively the wrong thing to do. But.. One does not maintain altitude by maintaining backpressure on the stick/yoke - if the aircraft is trimmed correctly then no direct input is required. I give you credit that it was not intended though. |
@franzl - No problem.
Note that the first action in the Stall Warning list is to set thrust to TOGA, which will give you a nose-up tendency anyway. In that case, maintaining altitude would be better served by pushing the stick ND. |
Checked the BEA transcript, nothing there, however it was mentioned on the Channel 4 program, so not sure if this is their "imagination"
I recently completed TR on A320, and we did do some stall practice, and was told first action now was stick ND - and than after TOGA! I was told this was something that had recently been changed. |
Originally Posted by truckflyer
(Post 7448011)
I recently completed TR on A320, and we did do some stall practice, and was told first action now was stick ND - and than after TOGA!
I was told this was something that had recently been changed. |
Actually you should not even use TOGA now, progressively increase thrust as required, after ND with the stick, to get you out of the stall.
It does seem in the start they believed the instruments, than they came to a stage of disbelief! Did the PF have a panic attack, holding the stick back without being aware what he was doing? As these stories are told, documentaries made, it is difficult to know what is the exact events, as sometimes things are omitted or added for effect of "entertainment" or creating a story! But the main focus what I have heard from other pilots that I know personally, friends of mine, is that the captain should never have left the cockpit for his rest at the time he did. All I spoke to said they would never have done that! |
truckflyer:
If you have the stomach for it, you'll see about every angle possible of the debate on this accident covered in fine detail in the discussions that began here in JUne of 2009, shortly after the aircraft was lost. Any number of pilots who have actually flown the ITCZ routes do not agree with your point on where rest is, yet others do. Best wishes on the reading, there is some good info and some good commentary, surrounded by no small amount of chaff. |
There are disturbing similarities between the drama of the Titanic and AF447
Popular "best machines" that human kind can construct (high technology concepts) Titanic Reputed as unsinkable because protections (watertight doors) AF447 Reputed as "can't stall" because protections Titanic: 1-They know (have warnings) of many ice and icebergs in the vicinity 2-They know (seamanship) that it's necessary to reduce speed 3-Captain Smith is not in the wheelhouse AF447: 1-They know they will crossing the ITCZ 2-They know (airmanship) that they can't climb safely 3-Captain Dubois is not in the flight deck Titanic: 1-They will put lookouts for ice 2-They will increase speed ! 3-They will not fully understand what happen (the severity of damages) and a officer will give orders for open hull gangway doors for embark passengers in the half-loaded lifeboats AF447: 1-They will set their weather radar for better detection of dangerous areas 2-They will climb ! 3-they will not fully understand what happen and take bad decisions Epilogue: Wrecks will be discovered after long and difficult research Their discovery will help to understand more or less what happened but there are still shadows The tragedy of the Titanic had results that some laws concerning maritime safety, construction and conduct of vessels have been modified It is certainly true with regard to the world of aviation |
Stall recovery training is a very interesting field of unintended consequences. We all learn stall recovery during basic training in docile aircraft relatively close to the ground. We are taught 'minimum height loss' which when practiced numerous times over a short period becomes in many pilots' minds 'no height loss'. To a degree this makes sense for the close to th ground case where there is not a lot of room underneath to recover.
But most of us end up in aircraft that fly well above the ground and hence we can safely trade height for speed. But even when we do stall training in a type rating course iris not enough to overwrite the earlier learning. So much for the problem, what about a solution? Why not include stall recovery in basic training where the student cannot use power? ie they must lower the nose and trade height to speed. This caters for cases such as severe icing when full power has already been applied and for the future high altitude case where full power and nose up is not appropriate. |
Lose no altitude, maintain back pressure. Thrust increase. Control may be compromised if TOGA is applied as this can generate a powerful pitch/thrust couple which can exceed elevator authority if the aircraft has auto-trimmed to the point of the stall. Pilots are also having to be reminded that 'minimum loss of height' may be undesirable as there may be occasions when the stall occurred because the aircraft was at excessive altitude for its weight. A positive manner, disciplined flight deck procedures, sound training and attentive monitoring are needed - none of which were evident in the AF447 accident. Why not include stall recovery in basic training where the student cannot use power? Notwithstanding an entirely adequate 'Unreliable air speed' QRH procedure, I do think that all large aircraft should be fitted with independent AoA gauges. |
Apologies if I have missed this in the welter of OOZLUM bird flocking, but do we know if AB have now addressed the logic for the stall warning 'inhibit' below 60kts?
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NOOO!!!
(I don't know how to say it louder). Please tell me that's not true, no one has ever said such a folly: Quote: Lose no altitude, maintain back pressure. Thrust increase. That nonsense has now been canned - it was some FAA Examiners' idiocy which was totally wrong. Both Airbus and Boeing have now had to rewrite their stall recovery procedures to ensure that the emphasis is on reducing AoA. 'Unload for control' was once a well-known maxim; sadly that seems to have been forgotten by many. Control may be compromised if TOGA is applied as this can generate a powerful pitch/thrust couple which can exceed elevator authority if the aircraft has auto-trimmed to the point of the stall. I think I have to stop teaching old stuff to my students and burn out all my manuals! |
Roger, the stall training and stall recovery training that I taught as a flight instructor did not have "minimum altitude loss" as a criterion, but there was a time when the approach turn stall training did have some attempts to "quantify" what number of feet lost was a criterion for success. I typically argued that if you teach good technique and good procedures, you will recover with minimum practical altitude loss. (Uh, and I was right about that).
I won't bore you with the various battles I fought over that, but do agree with you that stall training at altitude has numerous benefits, particularly when you teach it as a power independent training maneuver. |
Originally Posted by fustall
This was the start of the problem,how did Airbus get away with fitting inferior pitot tubes with inferior heating elements?
Originally Posted by Lonewolf 50
they made the assumption that stall warnings that they were receiving were spurious.
Originally Posted by Lonewolf50
I am not convinced that a 5 degree nose up pitch held ad infinitum would do other than slowly fly them into a stall, or slowly fly them to their service ceiling.
Originally Posted by jcjeant
why Airbus (in the first place) fitted those particular brand and patent (Thales) Pitot tubes ?
Originally Posted by Lyman
I disagree, utterly. you would enlarge your understanding manifold once hearing evidence that is unfortunately unavailable to you, or to the public.
The CVR tells BEA everything, they tell us next to nothing. It is quite possible the CVR will find its way into the public domain. If available to you, would you listen? Or would you cover you ears, satisfied with a 'story'...
Originally Posted by truckflyer
Furthermore to Airbus pilots, when did Unreliable Airspeed become a memory item?
Originally Posted by truckflyer
should they have been aware of these procedures.
Originally Posted by truckflyer
From what the TV program showed, however much is correct there I don't know, but it does seem like the PF (RHS) locked/jammed the controls for to long time!
Originally Posted by Lonewolf 50
Typically, airlines do not do actual stall training in the aircraft (valid risk and cost reasons),
Originally Posted by lonewolf50
That sort of training is apparently not done.
Originally Posted by Lyman
Lose no altitude
Originally Posted by Retired f4
Or you are talking about an aircraft, where autotrim is keeping the aircraft trimmed into the stall?
Originally Posted by BEagle
That nonsense has now been canned - it was some FAA Examiners' idiocy which was totally wrong. Both Airbus and Boeing have now had to rewrite their stall recovery procedures to ensure that the emphasis is on reducing AoA. 'Unload for control' was once a well-known maxim; sadly that seems to have been forgotten by many.
It hasn't been canned. It's just folks around still can't tell the difference between approach to stall recovery and stall recovery. Unsurprising if one can't tell the difference between the stall warning and stall.
Originally Posted by BEagle
Control may be compromised if TOGA is applied as this can generate a powerful pitch/thrust couple which can exceed elevator authority if the aircraft has auto-trimmed to the point of the stall.
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It is not nonsense. It hasn't been canned. It's just folks around still can't tell the difference between approach to stall recovery and stall recovery. Unsurprising if one can't tell the difference between the stall warning and stall. So what. If autopilot autotrimed, manual trim is available. If FBW autotrimed, stick forward causes trim to roll in the opposite direction. |
Hi,
clandestino ...yet some managed not to crash their 330/340s even without the training. Anyways I will not take the chance to jump without parachute := |
So much for the problem, what about a solution? Why not include stall recovery in basic training where the student cannot use power? ie they must lower the nose and trade height to speed. My honest opinion is that we are seeing the results (in a wide sense) of the continuing spread of high levels of automation, including FBW and envelope protection. Statistically, flying is becoming safer but when accidents do occur, they trend towards the "what's it doing now?!" and/or failure to intervene when the automation has become unreliable. I don't see much in the immediate future that's going to change this. Airline pilots who fly "conventional" airframes or light aircraft outside work get much more exposure to AoA, airframe performance and feedback; those whose only real handling experience outside of initial training is five or ten minutes in the sim every six months cannot be expected to have the same level of awareness or respond quickly in the appropriate manner when the computers give up and dump the whole thing in their laps. This is not a criticism of those pilots - we haven't yet got to a Matrix-style "I know Kung-Fu" as applied to aeroplanes, so there is little or no learnt/reflex behaviour to draw on in a problem situation. You can read the manuals as often as you like but nothing prepares you for the reality like continual practice. The statisticians have probably worked out that overall it's better to have the odd AF447 when the automation can't cope than to rely on humans for the rest of the time... |
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