AF447
Thread Starter
ahHAH.... "There has been an industry wide change in emphasis (all a/c types) in recent years where before a consideration was to minimise height loss whereas now the priority is to aggressively break the stall then recover, as the new emphasis actually results in less height loss." That makes perfect sense. If "Minimized height loss" was the goal, how to judge that? Especially when near the deck, even in the sim? Pucker ttime.This suggests to me that Approach to Stall on short final was done in Normal Law?? Wouldn't high altitude Stall Warning be "break the Stall? Many thanks, Locked door
Last edited by Concours77; 28th Mar 2023 at 20:17.
Don’t misunderstand, the priority was always to reduce AOA and increase thrust to end the stall and fly away. Previously the guidance was to recover the descent as soon as flying speed was achieved whereas now the guidance is to delay the recovery until the aircraft is really moving as some pilots were trying to recover too early causing a secondary stall.
The priority is, and always was, get the nose down and get the thrust on. What the AF pilots did is inexplicable.
What flight control law the stall training was done in is irrelevant, as the recovery is done inside the flight control envelope unless it is mishandled, in which case the training would be done again until it was done right. I suspect most training is done in alternate law as you can’t fly a recovery until the first sign of a stall, and you can’t achieve the first sign of a stall in normal law.
The priority is, and always was, get the nose down and get the thrust on. What the AF pilots did is inexplicable.
What flight control law the stall training was done in is irrelevant, as the recovery is done inside the flight control envelope unless it is mishandled, in which case the training would be done again until it was done right. I suspect most training is done in alternate law as you can’t fly a recovery until the first sign of a stall, and you can’t achieve the first sign of a stall in normal law.
Thread Starter
Locked door
"The priority is, and always was, get the nose down and get the thrust on. What the AF pilots did is inexplicable." So what we're left with is, were AB aircraft in Normal Law when practicing Approach to Stall down low? Training is important here, I think, the possibility for startle/confusion is clear, at least to this non big rig pilot ...
And..."I suspect most training is done in alternate law as you can’t fly a recovery until the first sign of a stall, and you can’t achieve the first sign of a stall in normal law." So, clearly PF AF447 knew the STALLWARN was legit, and he had to know they were in some type of AlternateLaw....which also means he knew AoA was a load factor request, and Roll was in DIRECTLAW...Thanks for your patience Ld
And..."I suspect most training is done in alternate law as you can’t fly a recovery until the first sign of a stall, and you can’t achieve the first sign of a stall in normal law." So, clearly PF AF447 knew the STALLWARN was legit, and he had to know they were in some type of AlternateLaw....which also means he knew AoA was a load factor request, and Roll was in DIRECTLAW...Thanks for your patience Ld
Last edited by Concours77; 28th Mar 2023 at 20:12.
And..."I suspect most training is done in alternate law as you can’t fly a recovery until the first sign of a stall, and you can’t achieve the first sign of a stall in normal law." So, clearly PF AF447 knew the STALLWARN was legit, and he had to know they were in some type of AlternateLaw....which also means he knew AoA was a load factor request, and Roll was in DIRECTLAW...Thanks for your patience Ld
I suspect he heard the 'You can't stall' and in the heat of the moment either didn't recall the 'in Normal law' part - and/or he never comprehended they were not in Normal control law. Further, he either didn't hear the "Stall Stall", or didn't comprehend it.
To me, this is a danger in telling pilots that you can't stall an aircraft unless it is in fact physically impossible to stall it (there are a few aircraft designs where the basic design precludes being able to get it into stall - I think the 'Verieze' falls into the catagory) - because in a startle/panic situation they may not recall any provisos to the 'can't'.
Join Date: Mar 2006
Location: USA
Posts: 2,523
Likes: 0
Received 0 Likes
on
0 Posts
Actually, I'm pretty much convinced that the PF did not know he was stalled - it's simply inconceivable to me that a trained pilot who thinks they are in a stall would continue to hold full back pressure for several minutes while the altimeter unwound to zero.
I suspect he heard the 'You can't stall' and in the heat of the moment either didn't recall the 'in Normal law' part - and/or he never comprehended they were not in Normal control law. Further, he either didn't hear the "Stall Stall", or didn't comprehend it.
To me, this is a danger in telling pilots that you can't stall an aircraft unless it is in fact physically impossible to stall it (there are a few aircraft designs where the basic design precludes being able to get it into stall - I think the 'Verieze' falls into the catagory) - because in a startle/panic situation they may not recall any provisos to the 'can't'.
I suspect he heard the 'You can't stall' and in the heat of the moment either didn't recall the 'in Normal law' part - and/or he never comprehended they were not in Normal control law. Further, he either didn't hear the "Stall Stall", or didn't comprehend it.
To me, this is a danger in telling pilots that you can't stall an aircraft unless it is in fact physically impossible to stall it (there are a few aircraft designs where the basic design precludes being able to get it into stall - I think the 'Verieze' falls into the catagory) - because in a startle/panic situation they may not recall any provisos to the 'can't'.
I also have a theory that he also suffered from automation dependency. He was just trying to keep the FD centered, because he’d never flown without them.
Thread Starter
Aren't the Flight DIrectors "OFF", either automatically, or turned off as a checklist item in UAS? From the CVR. "I have no vario..." (VSI). So if he mistrusts vertical speed, his descent is not acknowledged until 4000 feet: "We better pull, we are at 4000..." Afraid I rely alot on what and how they talk on CVR....it is the only eyewitness account we have. For good or ill, it suggests they (all three) never understood the airplane.. Except at the end of the recording...Captain: "Pitch ten degrees...." Then impact...I have a theory why he said that. He was one of the first at the accident scene...it was a witness statement...
Join Date: Sep 2016
Location: USA
Posts: 803
Likes: 0
Received 0 Likes
on
0 Posts
The FD's disappeared with the data loss, and then reappeared at +6000 fpm. You betcha he was following the FD with soda-straw vision on the one item most burned-in as the main concept of flying the airplane
Thread Starter
Vessbot
Join Date: Jun 2007
Location: Wanderlust
Posts: 3,407
Likes: 0
Received 0 Likes
on
0 Posts
Ever since AF447 happened and till the final report came out and even well after that this subject has been beaten to death with over 30000 posts till it was closed. And we are starting afresh treading the same path again.
Moderator
If it all gets too much of a repetition, we can lock it. However, let's leave it run for a little while to see if it dies a natural death first. If it gets onto generic matters there may be some training and/or learning value ?
Join Date: Jun 2007
Location: Wanderlust
Posts: 3,407
Likes: 0
Received 0 Likes
on
0 Posts
The discussion cannot add much to technology that existed in AF447 because in the past thread it has been thoroughly analysed, questioned, even misquoted and subsequently corrected. What the pilots did and why did they do what they did also has been discussed. The process went on for years. So there was nothing left to learn. Now the only interest should be what has Airbus done to avoid repeat or improve the outcome. With the latest modification it's virtually impossible to repeat 447 because in A350 it deals with it automatically without any pilot intervention and provides alternate speed to fly. In other aircraft like A320/330 it's auto detected and pilot is provided with actions to switch to alternate speed. So UAS now only is an issue with unmodified aircraft or aircraft with older modification where pilot identification of the situation is necessary before using the modified display to fly.
Amen to all the above; the 350 can even utilize the data being fed to the engines as additional back up. And GPS altitude. So, very clever in a Sorbonne kind of way and Airbus has moved on. Hopefully training organizations, airlines and pilots for that matter have as well by adopting regular exposure to UAS scenarios and unreliable airspeed. The 330 checklist for unreliable airspeed is very difficult to simulate, as by definition the very scenarios that you’re trying to emulate are nebulous and subject to change.
So it takes a very good instructor to run those sessions, understand them properly, teach at the same time and, demonstrate the procedures. Not just a question of activating the BUSS, although that does tend to be the final result. I can’t speak to the other Airbus types. And team B seemed easier overall.
At the end of the day it’s back to the old recall drills of pitch and thrust; in the old Jumbo it was 2 and a half, two and a half, and two and a half. 2.5 units of pitch, 2.5 units of thrust on the thrust resolver scale on the quadrant, 2.5 on the standby or other AI…. all derived from different sources. Will that maintain level flight at all points of the envelope ? No. Prob not. It will however prevent you pancaking an aircraft in to the sea. AIB have similar drills, dependent on stage of flight, take off, climb etc.
This thread should be laid to rest; some of the comments from the OP ( in particular about stall recovery procedures ) are frankly trollworthy and show us in a bad light.
So it takes a very good instructor to run those sessions, understand them properly, teach at the same time and, demonstrate the procedures. Not just a question of activating the BUSS, although that does tend to be the final result. I can’t speak to the other Airbus types. And team B seemed easier overall.
At the end of the day it’s back to the old recall drills of pitch and thrust; in the old Jumbo it was 2 and a half, two and a half, and two and a half. 2.5 units of pitch, 2.5 units of thrust on the thrust resolver scale on the quadrant, 2.5 on the standby or other AI…. all derived from different sources. Will that maintain level flight at all points of the envelope ? No. Prob not. It will however prevent you pancaking an aircraft in to the sea. AIB have similar drills, dependent on stage of flight, take off, climb etc.
This thread should be laid to rest; some of the comments from the OP ( in particular about stall recovery procedures ) are frankly trollworthy and show us in a bad light.
Join Date: Mar 2006
Location: USA
Posts: 2,523
Likes: 0
Received 0 Likes
on
0 Posts
The dust has settled on this accident; time to look at the residual patterns in this and other complex events.
Consider the human; not stick and rudder skills. The crew were qualified pilots; more training for them implies more training for all qualified pilots. If not why not, why would we be different.
The indications are that in this incident and similar, the circumstances exceeded human capability at that time in that situation. It is difficult to change human limitations, so change conditions of work.
Modified pitot tubes. BUSS recognises the importance of speed in surprising, albeit temporary situations. New research on how to alleviate the limitations of 2 out of 3 logic if all three systems fail (EASA).
Designing for Situation Awareness in Complex System
https://www.researchgate.net/profile...ication_detail
Note: "Expertise, therefore, can be seen to play a major role in the SA process. For novices or those dealing with novel situations, decision making in this environment will be an arduous task, requiring detailed mental calculations based on rules or heuristics, placing a heavy burden on working memory."
Expertise / novice relates to individual capability, not total flight time or which seat you sit in, it involves what is known (know what and know how), what can be recalled and related too in exceptional circumstances.
The Effectiveness of Airline Pilot Training for Abnormal Events
http://journals.sagepub.com/doi/pdf/...18720812466893
"… during a real flight, pilots’ responses frequently differed from accepted standards and showed greater variability."
An analysis of flight crew response to system failures
https://www.yumpu.com/en/document/re...ystem-nlr-atsi
"The results show that in 17% of the sample, crew response to system failures was inappropriate. The percentage of inappropriate flight crew response decreases from 25% for earlier generation aircraft to 4% for the newest generation.
The percentage of inappropriate response shows differences when various systems are compared, the lowest percentage of inappropriate responses occurs for flight control system malfunctions (8%), the highest percentage for instrument failures (48%). 11% of the investigated cases of inappropriate flight crew response involved wrong detection, 38% involved wrong diagnosis/decision and almost 51% involved wrong action.
Annunciators have a pronounced effect on the probability of failure detection.
Inherent cues play a relatively large role in decision failures. Inherent cues such as vibration, loud bangs etc., can be compelling, but are often not very conclusive or even misleading."
Consider the human; not stick and rudder skills. The crew were qualified pilots; more training for them implies more training for all qualified pilots. If not why not, why would we be different.
The indications are that in this incident and similar, the circumstances exceeded human capability at that time in that situation. It is difficult to change human limitations, so change conditions of work.
Modified pitot tubes. BUSS recognises the importance of speed in surprising, albeit temporary situations. New research on how to alleviate the limitations of 2 out of 3 logic if all three systems fail (EASA).
Designing for Situation Awareness in Complex System
https://www.researchgate.net/profile...ication_detail
Note: "Expertise, therefore, can be seen to play a major role in the SA process. For novices or those dealing with novel situations, decision making in this environment will be an arduous task, requiring detailed mental calculations based on rules or heuristics, placing a heavy burden on working memory."
Expertise / novice relates to individual capability, not total flight time or which seat you sit in, it involves what is known (know what and know how), what can be recalled and related too in exceptional circumstances.
The Effectiveness of Airline Pilot Training for Abnormal Events
http://journals.sagepub.com/doi/pdf/...18720812466893
"… during a real flight, pilots’ responses frequently differed from accepted standards and showed greater variability."
An analysis of flight crew response to system failures
https://www.yumpu.com/en/document/re...ystem-nlr-atsi
"The results show that in 17% of the sample, crew response to system failures was inappropriate. The percentage of inappropriate flight crew response decreases from 25% for earlier generation aircraft to 4% for the newest generation.
The percentage of inappropriate response shows differences when various systems are compared, the lowest percentage of inappropriate responses occurs for flight control system malfunctions (8%), the highest percentage for instrument failures (48%). 11% of the investigated cases of inappropriate flight crew response involved wrong detection, 38% involved wrong diagnosis/decision and almost 51% involved wrong action.
Annunciators have a pronounced effect on the probability of failure detection.
Inherent cues play a relatively large role in decision failures. Inherent cues such as vibration, loud bangs etc., can be compelling, but are often not very conclusive or even misleading."
Join Date: Dec 2018
Location: Florida
Posts: 247
Likes: 0
Received 0 Likes
on
0 Posts
Salute!
Thanks, JT, Td and vilas.
Many lessons to be honored with that tragic crash, and prolly more than crew coord, systems knowledge, side stick implementation, and such.
When I first read the CVR beside the FDR I cried... screamed at those guys. The first pics of the plane on the floor of the sea hit me as something from my past. I had been there ....... you know, you can not stall this plane, why am I going down so fast but the plane is not shaking or rolling a lot, and horns are going on and off.... Oh well....
I would invite those who wonder what some of us are talking about, then go to the closed thread and wade thru all the opinions, real world experiences and the technical stuff. Otherwise......
Gums sends....
Thanks, JT, Td and vilas.
Many lessons to be honored with that tragic crash, and prolly more than crew coord, systems knowledge, side stick implementation, and such.
When I first read the CVR beside the FDR I cried... screamed at those guys. The first pics of the plane on the floor of the sea hit me as something from my past. I had been there ....... you know, you can not stall this plane, why am I going down so fast but the plane is not shaking or rolling a lot, and horns are going on and off.... Oh well....
I would invite those who wonder what some of us are talking about, then go to the closed thread and wade thru all the opinions, real world experiences and the technical stuff. Otherwise......
Gums sends....
Thread Starter
alf5071h , 29th Mar 2023 07:14"The dust has settled on this accident; time to look at the residual patterns in this and other complex events. Consider the human; not stick and rudder skills. The crew were qualified pilots; more training for them implies more training for all qualified pilots. If not why not, why would we be different."
What a breath of fresh air. I couldn't have put it that way in a million years . (Obviously?) I have tried to ask questions from the point of view, (not that I could ever imagine the level of emotions) of the flight crew, shocked, puzzled, angry, etc. frustrated. You put it well...and I am personally grateful. I have learned, alot. Thank everybody for every post. Every one....
What a breath of fresh air. I couldn't have put it that way in a million years . (Obviously?) I have tried to ask questions from the point of view, (not that I could ever imagine the level of emotions) of the flight crew, shocked, puzzled, angry, etc. frustrated. You put it well...and I am personally grateful. I have learned, alot. Thank everybody for every post. Every one....
Join Date: Sep 2016
Location: USA
Posts: 803
Likes: 0
Received 0 Likes
on
0 Posts
The dust has settled on this accident; time to look at the residual patterns in this and other complex events.
Consider the human; not stick and rudder skills. The crew were qualified pilots; more training for them implies more training for all qualified pilots. If not why not, why would we be different.
Consider the human; not stick and rudder skills. The crew were qualified pilots; more training for them implies more training for all qualified pilots. If not why not, why would we be different.
Join Date: Jun 2007
Location: Wanderlust
Posts: 3,407
Likes: 0
Received 0 Likes
on
0 Posts
I'm not sure what you mean by considering the human without the stick and rudder skills, as it applies to this. The crew were qualified pilots in the sense of an official requirement being met by a bunch of boxes being checked, but lacked the stick and rudder skills necessary to meet the situation. To more training being required for them implying more raining being required for all qualified pilots, yes and yes.