AF 447 Thread No. 10 [Archive] - Page 4

PJ2

23rd Feb 2013, 16:10

Hi mm43;

It's my general impression that the circumstances faced by the two First Officers went rapidly beyond their experience and their training. I think this was partly due to the absence of a disciplined response to the event and to the ECAM. The PNF tried to "re-group", but such a response, when not initiated by the PF, is difficult to initiate or re-focus once the PF has already taken an independent course of action. The obvious solution was to take over and lock the PF's stick out of the loop but "the obvious" as it now appears to us gets into hindsight work which always has the solution!

In Canada, the CARS do not require that the stall be demonstrated on fbw aircraft once the initial PPC has been done on a type new to the candidate. In practical terms I believe this lack is being generally ignored and these events are actually being trained in recurrent work.

The one puzzle for me and for which it is impossible to determine a definitive answer is, why take a transport aircraft to a pitch attitude of 10 degrees at cruise altitude, at any time? Such pitch attitudes have an inevitable outcome in terms of rapid energy loss and as such are deeply ingrained and counter to experience in flying these aircraft.

A one-degree pitch change is dramatic enough, and so large changes are just never, ever done in normal flight conditions where the airplane was and remained stable, which this was. The assumption is that everyone knows this "through experience and their imagination" but perhaps that is not always the case especially where there is little to no opportunity to hand-fly these aircraft and / or it is never taught.

Many answers have been posited as to why the pitch-up...PF responding to loss of altitude (indicated...about 350'), or initiating the memory item of pitching the airplane up in response to the loss of speed indication (as per the UAS memorized drill), turbulence and inexperience in manual flying thus little appreciation of the massive inputs that small stick movements have, somatogravic illusions...There are numerous explanations which we, with full knowledge, may posit but can never know.

jcjeant

23rd Feb 2013, 19:42

Hi,

PJ2
Many answers have been posited as to why the pitch-up...PF responding to loss of altitude (indicated...about 350'), or initiating the memory item of pitching the airplane up in response to the loss of speed indication (as per the UAS memorized drill), turbulence and inexperience in manual flying thus little appreciation of the massive inputs that small stick movements have, somatogravic illusions...There are numerous explanations which we, with full knowledge, may posit but can never know. I think the answer will be found at the trial
Your Honor .. after deliberation we have a verdict:
Incompetence

Speed ...
http://i.imgur.com/GyPs35b.jpg
Alternate law
Also like you have overspeed ?

DozyWannabe

23rd Feb 2013, 19:52

But when it comes to the niceties of PFD color changes, and what the VSI does when you go 'off scale', this was beyond the PF's experience and training.

I don't think so - it's right here (Page PFD5 - top of the table - "PFD Altitude Indications" and PFD6 "Vertical Speed") :

http://www.airbusdriver.net/EFIS6.pdf

PJ2

23rd Feb 2013, 21:56

jcjeant, probably me but I have no idea what you're talking about, sorry.

gums

23rd Feb 2013, 22:04

TNX, Doze for the pages to show the displays.

For some reason, I wonder about the same "yellow" bars whether you're too fast, too slow, too whatever. Seems to me that slow or too steep or too high of an AoA or poor power setting should be red if low and green if at the desired condition ( up to a point) and then yellow or something to show above or below desired whatever. Then red is way outta line. In other words, keep everything green and you're as good as all the computers think you should be. And an arrow to show where you should be putting in controls. Of course, judgement and experience should take charge interpreting all the colors and raw data and colors, ya think?

'Bird and others here have flown the "indexer" doofers for AoA on approach, and they showed arrows to get to the desired value, and they were of a different color. Even we dumb fighter pilots could understand.

The early 70's lites had HUD displays that showed flight path ( FPM) WRT horizon and actual Earth. Trust me, a comfortable feeling coming off a CAT shot on a moonless night on the ocean. Ask any Navy Sluf or Hornet or Tomcat pilot.

In the AF447 accident, an inertial FPM would have shown the precise trajectory of the jet WRT the local level regardless of the air data. So no big deal. Keep the velocity vector on the horizon and then troubleshoot the air data problem.

Some jets had features to help "lead" course and vertical steering to the desired course, approach angle, whatever. We always looked at the raw data to ensure that Otto wasn't driving us into the mountain or the ocean.

I realize that installing and certifying a HUD for the commercial planes would be expensive. But I am here to tell you that it was one of the neatest things to have in low-vis approaches and when the air data went tits up due to iceing or otherwise. Always had the ADI for basic attitude and roll, but that FPM on the horizon line was of great comfort.

I am afraid that all the colors and such were of little value to those FO's on AF447, and some basic flying skills were also absent. CRM is another problem, as most here seem to agree.

jcjeant

23rd Feb 2013, 23:48

jcjeant, probably me but I have no idea what you're talking about, sorry. In case of over speed do you see the same SPD word on blue background ? like as you see in alternate law after AP and auto THR disconnected (AF447) ?

mm43

24th Feb 2013, 00:00

@DozyWannabe,

Thanks for the PFD link.

Well, neither the PF or PNF demonstrated any sign of experience with regard to the speed scales and the VSI. They may well have received the training, but demonstrably it was something they failed to 'take onboard'.

DozyWannabe

24th Feb 2013, 00:00

In case of over speed do you see the same SPD word on blue background ? like as you see in alternate law after AP and auto THR disconnected (AF447) ?

No - that display only appears if air data from the pitot system or the ADR is unreliable or unavailable. With overspeed I think you see a red strip appearing to the right of the speed tape and the speed is displayed as normal.

PJ2

24th Feb 2013, 07:40

jcjeant;

Thanks, now I see!

Below is an image of the PFD in Normal Law.

In Normal Law there is a green symbol which resembles an equal sign ( = ) which indicates when the VMO (or equivalent MMO) warning will occur. The symbol is removed when not in Normal Law. The alternating red and black strip is the overspeed regime. An overspeed is the lower of:

• VMO or MMO
• VLE
• VFE

An audible, non-silenceable chime sounds continuously until the overspeed condition no longer exists.

The overspeed warning functions in Normal, Alternate and Direct Laws. There is no speed protection in Alternate and Direct Laws.

http://www.smugmug.com/photos/i-29kdLFR/0/L/i-29kdLFR-L.jpg

jcjeant

24th Feb 2013, 14:49

@PJ2 and Dozy
Thank you for clarification

alogobotur

27th Feb 2013, 09:45

I am an layman in this area, but I've been intrigued by this plane crash, so I have done some researches, in order to explain to myself what had happened up there.

So, what is the situation with the AP? As I understood after the ice on pitot tubes melts, speed indicators went back to normal. Was it possible in that moment to switch on the AP? What is the procedure with AP switching on?

Was the plane simply falling from the sky, or it had also some horizontal speed? As I read the passengers were aware of the plane's loss of altitude?

After the ice from pitot melts (30 sec from AP swiching of, if I remember), all of the cockpit indicators worked normaly and there was absolutely nothing wrong with them?

Was there any chance of recovering the plane if pilot increased engine power, or it was already on maximum?

Why the captain did nothing about stall alarm? I can understand that pilots thought that it was false alarm, but when captain entered the cockpit, he had not any knowledge of what has happened. He entered, the pilot told him he has no control of the plane and the stall alarm sounded again. He never said anything about the stall?

Are the published transcripts full version of what were being comunicated in the cockpit?

Sorry if I am beeing boring to all of you experts

Lonewolf_50

27th Feb 2013, 13:27

alogo:
The answers to most of your questions are in the BEA Final report, with the exception of the mind reading required to understand why any of the three professional pilots did or didn't do what they did, or didn't, do.

The "why did they do that?" question gets partial answers via estimations made based on what evidence could be collected, as well as what general human factors knowledge has been accrued by the experts in that field.

If you haven't read the final report, I suggest you read it first, and then figure out which remaining questions you have.

It is linked to in various places on this web site in the AF 447 threads, such as here (http://www.bea.aero/en/enquetes/flight.af.447/rapport.final.en.php).

John Tullamarine has provided, here (http://www.pprune.org/tech-log/493472-af-447-thread-no-10-a.html), a wonderful resource for more reading and information.
So, what is the situation with the AP?
a. As I understood after the ice on pitot tubes melts, speed indicators went
back to normal.
b. Was it possible in that moment to switch on the AP?
c. What is the procedure with AP switching on?

After the accident, and after the unique recovery of the Flight Data Recorder, that information was reconstructed. It appears from the outcome of the flight that neither pilot understood that the airspeed indications had been restored, however, once stalled, that's a moot point until you unstall the aircraft. If you reconnect the AP in a stall ... well, since the Test Pilots aren't required to do that, and thus didn't collect data points on that, the result of that possible action is left open to guess work.

Beyond that, the situation with switching back on the AP is IRRELEVANT.

Pilots are required to be able to hand fly their aircraft in degraded modes. You restore the AP when you are content that you have cleared a malfunction and wish to use its features again. You have to fly the plane.
Was the plane simply falling from the sky, or it had also some horizontal speed?
Yes to both.
If you read the report, you will find that there was a forward vector.
But that doesn't matter all that much after you are stalled.
If you are stalled, your forward velocity simply influences the nature of impact when you crash, unless you make the inputs to recover from the stall and resome flying again. As I and a number of other contributors here have pointed out frequently, being STALLED is NOT FLYING, it is FALLING. Until you aren't stalled anymore, you aren't flying.
As I read the passengers were aware of the plane's loss of altitude?
How do you arrive at that conlcusion? And how does that matter? They were in no position to do anything about that. The pilots were. And didn't effectively take care of it. :( :{ RIP, 228 souls.
After the ice from pitot melts (30 sec from AP swiching of, if I remember), all of the cockpit indicators worked normaly and there was absolutely nothing wrong with them?
The reconstruction of the event via the FDR seems to show that, however, as I mentioned above, that is IRRELEVANT if the aircraft is stalled, and the recovery inputs to remedy the stalled situation are not made in a timely fashion. It is also of no help if the pilots don't recognize that the instruments are once again working properly. That appears to have been part of how this accident came about.
Was there any chance of recovering the plane if pilot increased engine power, or it was already on maximum?
The way to recover from the stall, once stalled, is to decrease angle of attack.
If you aren't yet stalled, and yet are close to a stall, sometimes/often increasing power (and accounting for the pitch up tendency that the increase in power will give you when using underslung engines) will speed you up and thus by the fact of airflow and physics, decrease your Angle of Attack sufficiently to prevent stall.

Once stalled, it is usualy required to lower angle of attack by decreasing pitch, and as the aircraft unstalls and returns to controlled flight, you'd usually use power to recover extra flying speed and restore altitude.
That's a general approach, each situation will have subtle differences. In this case, once stalled, if you go to TOGA, or Max Power, you may increase the pitch up due to the underslung engines, and make your stall recovery more difficult, not less so. Detailed discussion of this has taken place on these forums, and I invite you to head to the link I made up there (which John Tullamarine provided) and use the search tools he suggests.
Why the captain did nothing about stall alarm?
Why indeed? If we only knew.

I mentioned above that mind reading isn't something even the BEA can do in their investigation. None of us can either.

It isn't clear that any of the two, then three, pilots ever clearly identified and stated that "the aircraft is stalled" even though the stall warning was going off at various times during this accident.

My own estimate (guess) is that because there was a known airspeed error issue, at least one of the pilots presumed that a faulty airspeed/pitot system would lead to erroneous stall warning.
I cannot prove that, but it's one plausible explanation.
There are others, to include the belief asserted to be held by some people that an Airbus cannot stall. See the various threads for massive amounts of discussion on that little chestnut.
I can understand that pilots thought that it was false alarm, but when captain entered the cockpit, he had not any knowledge of what has happened. He entered, the pilot told him he has no control of the plane and the stall alarm sounded again. He never said anything about the stall?

Why indeed?
The answer to that remains in the grave.

The Captain was having to catch up to a deteriorating situation. Some of us guess -- and I say GUESS -- that his brief "this is not possible" comment may have referred to an initial diagnosis of "the plane is stalled" and his unwillingness to believe that his two copilots had somehow stalled the plane in the short time since he'd left the cockpit. But he may have been referring to something else, like the incredible rate of descent.
Are the published transcripts full version of what were being comunicated in the cockpit?
Apparently not.

There are ten separate threads on these forums on this topic, and a great deal of discussion on that point. See the link I gave to you for page one of this thread, where John Tullamarine has kindly provided many resource suggestions.

Suggest you PM jcjeant on that particular topic, or Lyman, as they are both quite vocal in their disappointment with the full CVR not being released.
Sorry if I am beeing boring to all of you experts
Not at all.
Read the final report. Ask questions.
There are some folks who can be of help.

:O

Lyman

27th Feb 2013, 14:08

It is inconceivable that the short, clipped phrases from CVR, released by the sole investigator, are the extent of pertinent conversation by this crew.

By definition, what is published is pertinent, and if one trusts the BEA, what is left out is not. BEA are not to be trusted with the rest of the recording.

All of the DFDR is available, unfortunately it does not converse, swear, or think.

There was discussion, in varying tones and inflections, that might perhaps further indict the aircraft?

alogobotur

27th Feb 2013, 17:10

@Lonewolf

Thnx for answering my questions. Firstly, I don't know why I can not quote posts, maybe because I am new here.

I started to read final report, but it is very massive text, and it takes a lot of time to read it. Not to mention that I am not an expert, and that report contains a lot of "strange" words for me.
I already saw 10 threads about AF447, but when working and having family it is very hard to read all that stuff in short period. I started to research this topic last month.

That is the reason why I oriented to the internet articles, forums and youtube, where the language is much more understandable. I understand in general what happened to AF447, but there are still a lot of black holes for me.

I know that noone can read pilot's minds, but that is why I want to hear something from the people who are also pilots, to hear what were they PROBABLY think, or why they probably done something. Understandably, reports won't say such things.

As I understood switching the AP on was not an option, it wouldn't help much.
I know that pilots were not aware that the indicators are OK, that was the "catch". My way of thinking was: "Nothing helps, we are falling, let's try with the AP switching on". Since I am not a pilot, that way of thinking is probably wrong :)

I watched the video on youtube where one investigator (I assume) said something like: "Most of the people were probably sleeping, so they did not know what was happening". From that (and my experience with traveling by planes) I concluded that passengers felt they were falling from the sky. I felt every time when the plane was decaying due to turbulences. Of course, this issue is not relevant to the air crash, just a little bit of human curiosity.

You said that it was irrelevant if the indicators worked fine, because the plane was stalling. The point is that obviously they did not belive that indicators are OK, because in that case they would believe that they are stalling and they would have done something about it. As I understood, although there was a lack of training with high altitude stalling, the point is that pilots DID NOT BELIEVE they were in the stall. If they belived it, they would have done something about it.

The pilots did not understand what was happening because they did not belive to the instruments, The AP was off, so they belive the stall alarm was also false.
My question here is: Is there any chance in that conditins for pilots to figure out what was happening, just relying on the cockpit view and the feeling? I read that in stall conditions there is some kind of "buffeting".

I did not pay attention to that captain's "It is impossible". So that was probably related to the stall warning as you said.

Another thing. From the last 1/2 minutes or so I conclude that Robert and Dubois realised the plane was stalling, after Bonin reveales that he was holding the stick back for the whole time? After that they were "mad" and try to put the nose down, as I understand.

Do you think that is likely?

jcjeant

27th Feb 2013, 18:41

How do you arrive at that conlcusion? And how does that matter? They were in no position to do anything about that. The pilots were. And didn't effectively take care of it This has indeed no importance to technical point of view and therefore this is not even important to the BEA investigation
By cons .. for the trial to come (when ?) it is very important
Be sure that the families lawyers will do everything in their power to demonstrate that the passengers knew that something unusual was happening
The benefits (money) will be greater if it is proved that the passengers knows that it was a problem (mental suffering .. stress .. etc ..)
BTW lawyers will certainly advance that it is because the captain (not in the cockpit but rather in the cabin) realized that something unusual was happening that he joined the cockpit
Hence his question (first words when he is in the cockpit)
What are you doing ?
And not ..(seems more logical for someone who don't know)
What happens ?
It was also some calls by one of the " cabin personnel ? "

Lonewolf_50

27th Feb 2013, 19:36

jcjeant, being afflicted by fear or mental anguish is irrelevant if the problem was dying, don't you think?

I suppose that the lawyers want to play the drama queens, so perhaps you are right.

As to your attempt to read the Captain's mind:

Given that he had to walk up a 10-12 degree nose up incline to get to the bloody cabin, of course he asked "what are you doing" as soon as he got in, given that he had turned the aircraft over at altitude in level cruise.

EDIT: I may have the time line all screwed up there, the nose may not have been that high as he responded to the call from the LH seat pilot.

Also, of course he asked "what are you doing" when he showed up, since he'd been paged less than thirty minutes after turning over the aircraft to his two subordinates.

He needed to know WTF was going on since what should have been happening was the plane proceeds toward Paris, as they had briefed, at altitude in level flight, at cruise airspeed.

We may also make the estimation that he had not fallen asleep, and that the roll excursions that went on initially had gotten his attention, and he wanted to know WTF was going on with all of this back and forth with the wings when the plane should be level at cruise ...

Lonewolf_50

27th Feb 2013, 20:19

As I understood switching the AP on was not an option, it wouldn't help much.
Yes. If your airspeed is unreliable, AP engagement won't work. (Anyone, please correct me if I said that incorrectly).
I know that pilots were not aware that the indicators are OK, that was the "catch". My way of thinking was: "Nothing helps, we are falling, let's try with the AP switching on." Since I am not a pilot, that way of thinking is probably wrong http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/smile.gif

Yes, that is wrong. :) Fly the plane, engage the AP once you have the plane behaving as your mission profile calls for.
I watched the video on youtube where one investigator (I assume) said something like: "Most of the people were probably sleeping, so they did not know what was happening".
That is a guess, but a good one.

In ten threads of discussion here, over three and a half years, a good analysis shows that the plane was in a modest nose up attitude and modest bank, for much of the descent and at impact. You'd want to read the FDR traces to see where it was nose high, lower, and how often the roll reached peak values. The nose was somewhere around 11-15 degres nose up when it stalled. Not quite as high at impact.

It seems that the aircraft did not have a significant airframe buffet while stalled. Following that line of thought, you would not "feel" it as with some other planes that shudder a bit more at stall, and when stalled.
From that (and my experience with traveling by planes) I concluded that passengers felt they were falling from the sky. I felt every time when the plane was decaying due to turbulences. Of course, this issue is not relevant to the air crash, just a little bit of human curiosity.
Probably not.
Once the plane settled into its descent, the "feel" would return more or less to "one G." The feeling you refer to is due to a transient condition. To apply what you feel as a passenger, you would expect the that the "feel" would be in the transitions, when something changes:
first, the climb before stall,
and then the onset of descent as the stall began.
Once established in the stall, the plane was more or less in a steady state descent.
You said that it was irrelevant if the indicators worked fine, because the plane was stalling. The point is that obviously they did not belive that indicators are OK, because in that case they would believe that they are stalling and they would have done something about it.
No.
They knew the indicators were giving them trouble, but you can't automatically infer from a bad indicator that you are stalling from that point of info alone.

A sound instrument scan should have alerted at least one of the pilots of the initial climb. At one point it did. He tried to get the other to "go down." The increasing rate of descent as the stall was manifested and began to take effect ought to have alerted one of the pilots, except for the point made that actual stall recovery on instruments isn't typically trained for. Stall prevention is.

Altimeters and Rate of Descent displays were both indicating a falling aircraft after the stall.
As I understood,
1. although there was a lack of training with high altitude
stalling,
2. the point is that pilots DID NOT BELIEVE they were in the stall.
3. If they belived it, they would have done something about it.
1. This appears to be a contentious point, since the industry has had upset training and understanding of upset for some years. Since certification didn't require exploring the stall envelope, the training is mostly in stall prevention, not stall recovery.
This does not appear to be an issue only at Air France.
That said, if you prevent stall, you don't need to recover from one.

2. Not "did not believe" they were in a stall but "did not recognize" they were in a stall. It can be reasonably concluded that what they didn't believe was the audio warning of stall. But we are indulging in a little mind reading, since not everything they thought is captured by something said on the CVR. Be careful.

3. I agree with this point, others may not.
2. The pilots did not understand what was happening because they did not belive to the instruments.
This is a debatable point. I would not put it that way.
What appears to have happened is their instrument scans broke down, to one degree or another, and the most useful information on the instruments was not what they paid the most attention to.
The AP was off, so they belive the stall alarm was also false.
No. That does not follow. Why they did not address the stall alarm, or comment on it, isn't so simple. AP being off had llittle to do with that.
My question here is: Is there any chance in that conditions for pilots to figure out what was happening, just relying on the cockpit view and the feeling?
No. They were flying in instrument conditions at night over the open ocean. You don't fly by feel in that case, you fly using you instrument scan. At least, you do if you don't want to get fooled by feeling and die.
That is a lesson written in blood over decades of flying.
I read that in stall conditions there is some kind of "buffeting".
That is a debatable point for the A330. It appears that the A330 doesn't buffet as much while stalled as some other planes do. gums described this as a "mushy" departure from controlled flight. This provisional conclusion was based on some detailed anlaysis of the FDR by some posters here, and I ask you to search that yourself.
I did not pay attention to that captain's "It is impossible". So that was probably related to the stall warning as you said.
Or not. There was so much going wrong that we cannot be sure what evoked that response.
Another thing. From the last 1/2 minutes or so I conclude that Robert and Dubois realised the plane was stalling, after Bonin reveales that he was holding the stick back for the whole time? After that they were "mad" and try to put the nose down, as I understand.
I'll leave that for others to guess at.
The other two may have figured out that they were stalled, but they didn't verbalize that based on what the CVR info we have available. Someone did a great job of reading out the decreasing altitude in the end game, per the CVR, but that didn't translate into effective action to recover from stall.

We have little evidence of an attempt to recover from stall by lowering the nose (some of the more informed estimates arrived at by various pilots here are that recovery would have had to begin somewhere between 12,000 and 20,000 feet to get unstalled and flying again. There were a number of discussions on how to figure that out, and I don't think a single conclusion was agreed.)
I don't recall who, but somebody did try this in a simulator. (Caution: the sims need data points from real flying to create good simulations, and nobody has done test flights of this plane into and recover from, stall.)

Based on the CVR and FDR, there is some evidence that, without saying anything about a stall, there was an advance of the throttles to TOGA that might have been related to the sound of stall warning. Granted, this was probably based on a drilled response for a problem at lower altitude, but once again there is a bit of guesswork involved here.

Look up Unreliable Airspeed procedure for more detail. Lots of discussion on that. (UAS is I think the acronym used in these discussions).

As I noted above, if you aren't already stalled, added dpower might help, but if you are already stalled, that may hurt your chances of recovery.
Do you think that is likely?
A lot of things are likely.

What was unlikely was that AF447 fell over 35000 feet to the sea from straight and level cruise flight. But it happened anyway.

You may wish to look into the discussions of Thales versus Goodrich pitot tubes, or pitot probes, to understand why the airspeeds became unreliable and got this chain of events started.

henra

27th Feb 2013, 20:51

Given that he had to walk up a 10-12 degree nose up incline to get to the bloody cabin, of course he asked "what are you doing" as soon as he got in, given that he had turned the aircraft over at altitude in level cruise.

Taking into account that significantly before he reached the cockpit the plane had exceeded the apogee of the trajecory and started decending he might not have felt the incline exactly like in a stable environment due to the fact that the inclined floor started falling and deccellerating at the same time. Must have felt interesting. Tilted floor but no additonal effort for climbing up a 10° slope. The decelleration might have masked the incline to some extent.
This fact might have contributed to the captain not exactly recognising the attitude when reaching the cockpit.
So at least a small portion of somatogravic illusion is conceivable.

That said the combined neglect of all three regarding the attitude indication and VSI still seems incomprehensible. Seems they were so overwhelmed and 'in action' that they never tried to step back and develop a mental picture of where and how they were moving in space.

PuraVidaTransport

28th Feb 2013, 00:57

Yes. If your airspeed is unreliable, AP engagement won't work. (Anyone, please correct me if I said that incorrectly).When the plane reverted to Alternate Law (2B if I remember correctly), engaging the autopilot was not an option. Once latched into alternate law, the autopilot can not be reengaged until the system is reset on the ground.

My only questions still outstanding in this mystery (outside "What were they thinking") is why with several nose-down inputs to the control stick, some lasting several seconds, why the elevators never moved into a nose-down position. With old cable controls, if you put the stick all the way forward the elevators would instantly respond with nose-down movements however, in the Airbus fly by wire, the elevators never got into a nose-down configuration despite several full nose-down stick inputs. They began to move a bit but were still in a nose-up position the entire ride down. I've wondered if there is a cumulative effect with all the nose-up inputs that delayed the movement of the elevators. The THS I understand...since the elevators never moved to a nose-down position I wouldn't expect the THS to move that way either. I've asked that question a couple of times and no one seems to know :ugh::ugh:

Edited to add: Looking back at the traces, there is around 15 seconds of nose-down stick from 2:13:45 to 2:14. The elevator was at 30 nose-up and in that 15 seconds of almost full nose-down stick, the elevator only moved to 15 nose-up. So even though the pilot commands nose-down, the fly-by-wire never moved the elevators to a nose-down position...for 15 seconds!!! As they only had a bit over 4 minutes from start to finish, I find that response time to pilot inputs awfully slow. Granted, by this point, it was to late to recover but if they had begun a recovery much sooner, such slow response to pilot stick input would have made recovery very difficult, especially considering the THS never moved from full nose-up. If it only moves 1 degree per second, that would mean almost a full minute of full nose-down stick would have been required to get the elevators to full nose-down with the THS beginning to move that way at some point in the process. So just how long would it have taken, with full nose-down stick, to get the elevators and THS into a nose-down position??

CONF iture

28th Feb 2013, 03:37

Looking back at the traces, there is around 15 seconds of nose-down stick from 2:13:45 to 2:14. The elevator was at 30 nose-up and in that 15 seconds of almost full nose-down stick, the elevator only moved to 15 nose-up. So even though the pilot commands nose-down, the fly-by-wire never moved the elevators to a nose-down position...for 15 seconds!!!
But as the CPT PITCH COMMAND is for ND the FO one is for NU, except for only 7 of those 15 seconds.
Also for that period the vertical acceleration is already slightly below 1.0 even with the elevators in a still UP position therefore the pitch law in force at the time is honored versus the request.

Direct Law would have been my choice too ... and also mainly for leaving the trim alone in the first place.

alogobotur

28th Feb 2013, 07:31

What is happening in that Airbus if the inputs from the pilots are opposite?
I saw comments like "dual inputs" in the reports. Does this mean that one pilot is giving nose-up inputs, the other one nose-down?

What is happening in that situation, who does the plain "listen"?

Lonewolf_50

28th Feb 2013, 14:16

The plane averages the inputs. If you are pulling nose up six degrees, and Im an pushing down six degrees, the plane will be about nose level.

Remember, the design and intention of this aircraft, a multi crew airline transport aircraft, was based in the law/rule (and common practice) that only ONE pilot is in control at a time. Rather than letting the sysetm go ape if two pilots "fight over the controls" the aircraft system enforces electronically, via the flight control system, a disincentive to have two people trying to fly at once. That's not that bad of an idea, actually.

Since so much of the flight control movement is via computer, electronics, and hydraulic linkages, two pilots puttting contradictory inputs in at the same time could well break something.

That would not be good, when it comes to flight controls.

Lonewolf_50

28th Feb 2013, 14:25

PuraVida:
When the plane reverted to Alternate Law (2B if I remember correctly), engaging the autopilot was not an option. Once latched into alternate law, the autopilot can not be reengaged until the system is reset on the ground.
Thank you for the more precise and more accurate statement. :ok: I had forgotten the latching in 2B.

algo, what that means in layman's terms is that not only will AP not function when certain data is unreliable, like airspeed, (the computer for the A/P has a logic function that detects conflicting data and at best avoids applying bad data to flight control inputs), but in the case that the degradation takes the plane into a control law called alternate 2B, you can't even put A/P on until you get to the next landing and maintenance facility and have the various features checked and reset.

Again, you don't actually need Auto Pilot to fly. You can fly the plane without it. (It's a bit more work for the crew to do so, however).

In other control laws and modes, you could reset it in the air once the airspeed data problem gets sorted out.

You are welcome to search Control Laws in the series of threads on this based on the link I gave to you for page one of this thread.

A great deal of very educational discussion was posted here regarding how A330 Control Laws work. These aren't the AutoPilot per se, but the compbination of mechanical, electric, hydraulic, and computer driven inputs to the positioning of the flight controls as a response to pilot action, or level of AutoPilot pilot assistance selected for a given phase of flight.

jcjeant

28th Feb 2013, 14:48

A great deal of very educational discussion was posted here regarding how A330 Control Laws work. These aren't the AutoPilot per se, but the compbination of mechanical, electric, hydraulic, and computer driven inputs to the positioning of the flight controls as a response to pilot action, or level of AutoPilot pilot assistance selected for a given phase of flight. I'm certain that the pilots of the AF447 had read and learn it time ago before it was posted here
However it does not have served them a lot to regain control of the aircraft
I think they had to learn other things .. or they had already learned it .. but forget it just when they need it so much ..

Lonewolf_50

28th Feb 2013, 14:59

jc, your opinions aren't helping explain this to a layman.

The dual problems of training and proficiency have been beaten to death. I am trying to make neutral and helpful replies. Where I fail to do so, please help explain to this layman.

Our friend algobotur initiated his inquiry with a seeming belief in AutoPilot as a tool and a fail safe. I have tried to explain to him how that is an invalid approach to take in understanding this tragic accident.

The core flying principle involved in my explanation to a layman is that you fly the airplane, and use various AutoPilot features help you in doing so, or in managing your task load. I suppose we should explain that AutoPilot is required for use as much as possible by many companies since they find fuel (and thus cost) savings from modern automated flying tools.

I suppose we can then explain that if the pilots, like our departed friends in AF 447, spent a great deal of their flying time monitoring the function of AutoPilot rather than flying themselves, the sharpness of their hand flying skills may have eroded. I think it's fair to say that many pilots believe that industry wide situation contributed to this accident. But that's also a conclusion with significant discussion and debate remaining.

It ought to be a major point of concern to the airline industry, since the pilot is expected to fly the plane regardless of how many sub systems are acting up.

Whether or not Air France, and its pilot training and quality programs, are about the same as, worse than, or better than the industry norm is to me unknown, and may be unknowable.

EMIT

28th Feb 2013, 21:59

A couple of posts ago, somebody asked about inputs by both pilots at the same time.

Actually, the reaction to such a situation by the aircraft is not so different in a Fly by Wire Airbus than in any other aircraft.

If in a yoke equipped aircraft, one pilot pulls the yoke with a force of 30 Newtons and the other pilot pushes with a force of 15 Newtons, guess what, the strongest force wins and the yoke moves in the pull direction.

In an Airbus, this happens electronically: 30 N pull minus 15 N push is equal to 15 N pull.

The difference is - electronic addition is not felt by the pilots, they do not feel that the other guy is also handling the controls. With a yoke, you can feel whether the other guy is interfering with the controls.

Busserday

28th Feb 2013, 22:43

One sidestick at the forward stop and the other at the rearward stop equates to both neutral sticks regardless of the force (pressure/torque) applied, does it not?

PJ2

1st Mar 2013, 00:30

"One sidestick at the forward stop and the other at the rearward stop equates to both neutral sticks regardless of the force (pressure/torque) applied, does it not? "

Yes, that's correct. I don't think the example using control columns is quite correct but I know what the poster is getting at. In the example, the CC would move in the direction of the greater force and the airplane would respond according to the extent of the movement which would, in the example, continue until the CC hit the stops (commanding full-up control deflection), while in the Airbus the SS movement (in degrees) is algebraically summed and the output to the flight controls is that sum. In the case where the sticks are at full deflection but in the opposing directions, the output commanded is neutral and no control deflection occurs.

The fact that the other pilot cannot know what input is being made and therefore cannot make correct assessments as to aircraft handling is the reason why dual inputs are prohibited. The correct procedure is to press the takeover button which temporarily locks out the other sidestick. Keeping the button pressed for (IIRC) 45 seconds locks out the other sidestick until landing.

jcjeant

1st Mar 2013, 01:42

while in the Airbus the SS movement (in degrees) is algebraically summed and the output to the flight controls is that sumEven this definition is not strictly accurate (pedantic .. lol)
If it was really the sum of the degree of displacement of the joysticks .. when both joysticks are in the same extreme position the output (deflection) should be double that obtained with a single joystick ... which is not the case .. so it might be simply that this is a algebraic sum if both joysticks move in the opposite direction ..

fizz57

1st Mar 2013, 07:54

No jc the inputs are always summed even if they are in the same direction, however the output is limited to full deflection.

Thus 1/2 NU+ 1/2 NU= full NU, any further NU deflection of either sidestick causes no further effective input.

Source: smartcockpit.

Try actually doing some reading before expressing an opinion, will you? You're reminding me of anothe very opinionated guy who had to "refer to FCOM" to find out how the airbus AT behaves with the lever out of climb...

alogobotur

1st Mar 2013, 07:55

Thx for the AP answers. So, AP switching on was not an option at all. It was also technicaly impossible.

The other thing, what was the situation with the AF447 radar? They were obviously flying thru the storm, why they didn't go around it? As the transcripts say, Robert said to Bonin something like "don't you want turn to the left" and then he turned to the left, but obviously didn't avoid the storm.

In one video I hurd something that this radar also could be misfunctional?

I know all of these questions are probably answered in the Final report, but this is much more easier way for me to have the answers:)

Lonewolf_50

1st Mar 2013, 13:00

They did in fact make a course deviation, but the freezing up of the pitot tubes was not due to being in a "storm" per se, it was due to the character of frozen water droplets at altitude and a pitot tube that wasn't as able to handle that problem as other pitot tubes one could equip an aircraft with.

You will need to go back to threads 1, 2, and 3 and read about the in depth discussion on the radars and pitot tubes to help flesh out this answer.

Remember this: passenger aircraft flying at similar altitudes carrying hundreds of passengers cross through the ITCZ (http://www.google.com/url?sa=t&rct=j&q=itcz&source=web&cd=1&cad=rja&ved=0CC8QFjAA&url=http%3A%2F%2Fen.wikipedia.org%2Fwiki%2FIntertropical_Con vergence_Zone&ei=rbIwUaj9PPHw0QG8tYHoDw&usg=AFQjCNFjSu8FygabQkeouCT00_ELm3VPWA&bvm=bv.43148975,d.dmg)every day and don't crash.

"They flew into a storm and crashed" is a red herring.
If you bother to read the history of this investigation and this flight, a few things become apparent:

1. The pitot tubes (all three froze up) were scheduled to be replaced in Air France aircraft, and some already had been, but had not yet been replaced on this particular jet. There was an airworthiness bulletin to that effect published a some months (years?) before this accident.

2. The pilots had already slightly reduced speed to account for flying through/near a storm and expected turbulence before they ran into that pitot icing problem.

3. The pitot tubes being rendered unreliable for a short time due to a particular kind of high altitude ice crystals made for unreliable airspeed.

4. The procedure for dealing with that at high altitude appears not to have been followed. That said, the UAS procedure has come under review since that accident. Many discussion on how to train for that malfunction have been recorded in the threads, on this topic. Use the search function on page on to find them.

5. Even with a less than stellar response to the UAS problem, a great many pilots who have years and years of experience flying that route will tell you that setting the correct pitch and power for the altitude and speed desired will keep the plane mostly level, at cruise, until the crew can sort through the malfunction and get the various systems back on line.

Point 5 is a pilot thing, not a machine thing.

While there was a machine malfunction, the pitot tubes taking time off due to ice crystals, most machine malfunctions have a series of procedures and remedy that the pilots apply to mitigate their impact, and to restore performance. The UAS procedure is one such remedy procedure.

The core pilot problem was in not applying the simple measure of flying an acceptable pitch and power while the NON-flying pilot would work through the systems to get them back on line. A contributor to that problem in this case seems to be the lack of hand flying time a lot of air transport pilots get at altitude in many fly by wire jets. If you don't practice something, your skills will be rusty when you need them. This is, based on the inputs of many professional pilots who post here, an industry wide problem.

The core machine problem began as all pitot tubes failing to function (even though there are three to provide redundancy), in part due to an already identified sub-par set of tubes being installed and not yet replaced by better tubes. Airspeed indication and input into the flight system is a crucial bit of information for both pilots and computers to use when flying the aircraft.

The radar don't really enter into it. The judgment call on how far to deviate from a given weather system is just that, a judgment call. Feel free to read the hundreds of posts on that element of this accident. The opinions among those who fly big jets for a living varies a bit on that point.

With that in mind, many experienced pilots note that some of the other intercontinental flights that night had deviated further around the weather system than AF 447 did. The analysis of the FDR data, once it was recovered, didn't show a significant amount of storm associated turbulence to have been a factor in the flight departing controlled flight. (Stall is a departure from controlled flight).

6. There were 32 incidents in the years previous to this mishap of unusual aircraft behavior and upset that were somewhat similar to, though not identical to, the malfunction the AF 447 crew ran into.
None of the others crashed, though some of them had bizarre altitude excursions that they had to deal with. A Qantas flignt (QF 32?) is one you might want to read up on for its similarity to the AF 447 accident.

Once again, please read the report.

Chris Scott

1st Mar 2013, 14:53

Quote from Lonewolf_50:
"Once again, please read the report."

Good advice....

You could read it (http://www.bea.aero/docspa/2009/f-cp090601.en/pdf/f-cp090601.en.pdf) slowly ten times over, and analyse the DFDR traces at length, in the time it would take to read all the AF447 contributions - good, bad, irrelevant, bigoted, open-minded, pig-headed, inquisitive, perceptive, indifferent, and even brilliant - on this forum.

And that short list of adjectives could no doubt be amplified.

CONF iture

1st Mar 2013, 16:59

The difference is - electronic addition is not felt by the pilots, they do not feel that the other guy is also handling the controls. With a yoke, you can feel whether the other guy is interfering with the controls.
... And also by how much he's interfering with the controls. It is direct first class information.

Electronic addition can take place without aural warning too ...

CONF iture

1st Mar 2013, 23:20

Keeping the button pressed for (IIRC) 45 seconds locks out the other sidestick until landing.
Not necessarily until landing as a deactivated sidestick can be reactivated at any time, by momentarily pressing either takeover pushbutton on either stick.

A33Zab

2nd Mar 2013, 08:10

PuraVidaTransport:

When the plane reverted to Alternate Law (2B if I remember correctly),
engaging the autopilot was not an option. Once latched into alternate law, the autopilot can not be reengaged until the system is reset on the ground.

alogobotur:
Thx for the AP answers. So, AP switching on was not an option at all. It was also technicaly impossible.

In fact its a little bit more complicated.

The AP(AUTOMATIC FLIGHT) can be engaged in both NORMAL as ALTERNATE LAW!.

The AP has its own 'law' built in and 'bypasses' the MANUAL control laws inside the FCPC(aka PRIM).

The AP commands direct flight surface deflection orders to the FCPC, the role of FCPC in automatic flight is to limit those orders when it 'senses' to be required so and to transfer the surface commands to the slaved FCPCs and FCSCs and their respective servos.

The AP however needs reliable airspeed parameter (to set the gains) and VLS(lowest selectable speed) to be available for operation and that was absent in this case.

PuraVidaTransport:
I find that response time to pilot inputs awfully slow

Apart from the explained SS algebraic addition:

Due to missing airspeed parameters, the filtergains of the flight control law were set to a fixed high speed value (IIRC 330KT).
This combined with the rather small integral(in time) part of the SS order resulted in this 'sluggish' elevator reaction but as one can extract from the FDR traces the reaction of the aircaft was a negative pitch and a positive Nz as commanded.

CONF iture

2nd Mar 2013, 13:39

Due to missing airspeed parameters, the filtergains of the flight control law were set to a fixed high speed value (IIRC 330KT).
Would filter gains apply to Direct Law too ?
In other words, is Direct Law that much 'direct' after all ?

All of the DFDR is available
Where ?

Lyman

2nd Mar 2013, 14:18

CONFiture

Quote:
Originally Posted by Lyman
All of the DFDR is available

"Where?"
At Court, to the Judge.

Autopilot is available to the flightcrew after UAS, Airbus (OEB) directed crews to not select it, as it "may" cause an "uncommanded climb" creating "risk".

It is BUSS that disqualifies A/P, until a reboot, on the deck...imo. Also I think NORMAL LAW is not reselectable post BUSS.

Captain DuBois, in the CVR, made it a point to check the A/P switch, late in the game. Why? Did he cycle it? The CVR reports (CAM) a noise of switch movement? Was he concerned about the "sluggishness" of the elevators? Whether due Bonin's pulling, Captain was obviously concerned about the lack of ND? I cannot find any command from Captain: "Putz!, NOSE DOWN" Can You?
Instead, the command is "Try Climb" "But I have aft stick for awhile..." Elevators were the topic of the day, yet all were at a loss as to continued descent.....

The instruments were alive, and accurate, we think, wouldn't the commander be distressed at the NU along with the 10000fpm descent?

WITHOUT QUESTION, the Captain must have assumed the controls were INOP, hence no NOSE DOWN response from the A/C. Where is evidence of his dilemma as to no ELEVATOR control? If he considers Bonin competent to fly, he can have no other conclusion, nor can Robert, who has been privy to the a/c PITCH migrations, from the outset.

Captain not once looks at Bonin's stick, just to make sure? Baloney. Something is fishy here. Robert is satisfied that the a/c is at fault, he must be, he agrees with Bonin "We have lost all control". Not a peep about the climb when DuBois returns?

As to CVR. Failing a release of the (complete) record, perhaps the BEA would consider releasing the audio portions that were transcribed.

Why not? The words are released, why not the voices along with them?

Any guesses?

bubbers44

2nd Mar 2013, 19:44

Two pilots couldn't hand fly. The Pitot system failed. They did not use the loss of airspeed checklist but pulled up 11 degrees into a full stall. Everybody knows you can not pull up to an 11 degree attitude at FL350 but they did. Now they hold this full nose up attitude for over three minutes until impact with the ocean. The captain that can hand fly comes up in the last minute and sees something he has seen before. Full stall, full back side stick and it is too late. Why do airlines hire these computer operator button pushers? Botom line always says hire the low time guys because they will fly cheap. It ain't cheap when you dump an airbus in the ocean with about 250 souls on board. This crash was so avoidable with a competent crew.

A33Zab

2nd Mar 2013, 23:43

Would filter gains apply to Direct Law too ?
In other words, is Direct Law
that much 'direct' after all ?

No speed gains for DIRECT law.

In (FCPC) DIRECT law the maximum elevator deflection depends on CG position and (in both FCPC as FCSC DIRECT law) on slat and flap position so that the load factor is limited at high speed and a minimum maneuverability is obtained at low speed.

CONF iture

3rd Mar 2013, 21:25

No speed gains for DIRECT law.
So beside the fact that the THS would not have gone to such wild setting, any ND command would have had much more effect.
I'd really like to see 2 simulations done side by side with the same inputs, one in the AF447 Law and the other in Direct Law ...

bubbers44

3rd Mar 2013, 21:53

Who cares what law it is in. Hire pilots that can fly in any law. That is what us old timers had to do. Why make it easy to be an airline pilot just because they fly cheap? Go back to when we got hired and make them show they can actually fly an aircraft without a computer pad. Cost???

Lyman

3rd Mar 2013, 22:11

CONFiture

So beside the fact that the THS would not have gone to such wild setting, any ND command would have had much more effect.

So too would any NU command? Instead of a chronic and persistent ~1G loss of energy to Stall, the wings in DIRECT LAW, given similar pilotage, would STALL at a lower altitude, sooner, (higher airspeed), and with some actual departure, not the "Mush" that gums says, (I agree). A definite rumble, break, and drop of the NOSE.

Perhaps a spin as well? With Roll DIRECT, who could say?

But the aircraft would be in a position to regain flying speed, (Nose Down), with an alerted pilot, via the break, and three pilots aware of the STALL..... And no OVERSPEED protection to muck things up...

DozyWannabe

4th Mar 2013, 01:02

I'm getting that sense of recursive déjà vu again. We've been over this so many times in the previous threads, so what do we say to a little realpolitik?

CONF, Lyman - I'm sure you and others would find such an experiment interesting, and truth be told you could probably derive any conclusion you wanted from the results.

But looking at it from a practical standpoint, the only reason to make a fundamental change in the behaviour of autotrim in Alternate Law (outside of better feedback on what it's doing) would be if the crew input was a reasonable course of action and in keeping with basic aircraft handling principles and the system responded in a way that had a detrimental effect on the outcome.

Now I'm sorry, but no matter which way you slice it - based on the evidence available the reactions of the crew of AF447 were neither reasonable nor in keeping with basic aircraft handling principles (NB : This is a purely factual statement, not an attempt to apportion blame or responsibility).

@bubbers44:
Two pilots couldn't hand fly.

The devil's in the details. In fact the PF (F/O Bonin) was a sailplane pilot with advanced qualifications, so he'd likely have been better versed in stick-and-rudder than many of his peers. The key detail is that they had no experience or training in high-altitude manual handling.

Machinbird

4th Mar 2013, 01:32

The devil's in the details. In fact the PF (F/O Bonin) was a sailplane pilot with advanced qualifications, so he'd likely have been better versed in stick-and-rudder than many of his peers.Yeah right. But wasn't Bonin flying with his feet flat on the floor? That leaves only stick skills and those were clearly not up to the task.

DozyWannabe

4th Mar 2013, 01:45

I don't know - I don't even know if it was established. The point I was getting at is that saying "the pilot(s) couldn't hand-fly" is inaccurate and prone to be repeated in that distorted fashion.

What is not in question is that on this particular occasion they *didn't* hand-fly correctly, and that they were never given training in high-altitude manual handling. A sorry state of affairs regardless, but it's a lot different than saying they were simply unable to hand-fly, period.

Machinbird

4th Mar 2013, 02:38

Dozy
Don't want to belabor the point, but you don't have enough experience in a cockpit to really understand the fundamental way that proper flying methods were violated. You do a pretty good job, but sometimes you draw some strange conclusions----and I attribute that to lack of hands on experience.

Generations of pilots learned to fly smoothly by a proper use of the trim controls. The Airbus architecture minimizes the value of this skill and modern flight management systems instead place a lot of importance on typing skills and staying ahead of the computers. The job is changing, but occasionally the old skills are all that stand between success and abject failure.

jcjeant

4th Mar 2013, 04:05

What is not in question is that on this particular occasion they *didn't* hand-fly correctly, and that they were never given training in high-altitude manual handling. A sorry state of affairs regardless, but it's a lot different than saying they were simply unable to hand-fly, period. So .. the company that employed the pilots felt that A330 does not require knowledge of manual flight at high altitude
What knowledge and tests has proved to be able to hold an airline transport pilot certificate such as that held by the AF447 pilots?
Is that these tests contain manual flight (real ..not simulation) of widebody at high altitude ?they *didn't* hand-fly correctly, and that they were never given training in high-altitude manual handlingSo all time for those planes (AF) that are at high altitude ( great percentage of the flying time) .. this is a potential catastrophe in the waiting .. if a pilot touch the joystick and pedals ?
What a beautiful battlefield for lawyers :)

A33Zab

4th Mar 2013, 10:06

I'd really like to see 2 simulations done side by side with the same inputs,
one in the AF447 Law and the other in Direct Law ...

There was a simulation done without any SS input, that would have been their best option.

Since the majority of inputs was NU, I don't think the outcome would be much different.

DozyWannabe

4th Mar 2013, 12:42

Generations of pilots learned to fly smoothly by a proper use of the trim controls. The Airbus architecture minimizes the value of this skill...

Well yes, but that doesn't make the Airbus FBW system bad, dangerous or worse than anything else - it's just an iterative example of how technology has changed. I don't mean to sound disrespectful, but isn't there a hint of "why can't they just do it the old-fashioned way" about that point?

...and modern flight management systems instead place a lot of importance on typing skills and staying ahead of the computers. The job is changing, but occasionally the old skills are all that stand between success and abject failure.

That's a different issue - modern FMS is not related to how Airbus set up their FBW flight deck - indeed it's not even an Airbus-only issue!

In this case, the old "fly by trim" skill would not have helped. All they needed to do was leave the stick alone and see how the aircraft behaved after AP disconnect. Of course, they should know enough to check the trim wheel setting if things are doubtful, and correct if necessary, but you can train that in the sim.

Lyman

4th Mar 2013, 13:25

Since the majority of inputs was NU, I don't think the outcome would be much different.

If the majority of inputs had been NU in DIRECT? Would they? Leaving in load for pitch command whilst roll is direct sounds like a mistake a human would make. And not a pilot.

Tens of millions of people are aware that PITCH/AoA did these gents in. The pilots ignored 'assiette'?

No discussion of AoA on deck of 447? None. The single most important data in the accident, and no evidence of awareness of it in the published record?

As if Pitch and AoA are unknown in aeronautics? Not a word?

The only hint is when we hear, "Try Climb"? Three certificated pilots ignore completely the mechanism that will kill them all? I may be the only one, but it is not possible that with all the upset and LOC, assiette was not mentioned, not once.....

And their lasting legacy is the broken record from bubbers44?\

CONF iture

4th Mar 2013, 13:42

There was a simulation done without any SS input, that would have been their best option.
Correct, but no pilot would accept to remain steady 3 or 400 ft below in RVSM airspace ... and again, why a proper information/training (http://www.pprune.org/7450265-post576.html)was not naturally put in place as Airbus had all the data ?

Since the majority of inputs was NU, I don't think the outcome would be much different.
That has to be seen - NU inputs are effective no doubt but the THS does not collaborate ... Maybe they still go to the stall ... but that's not that easy ... and that's not that easy to maintain ...

Some experiment has to be done.

Lonewolf_50

4th Mar 2013, 13:44

Lyman, as has been discussed before, there isn't an AoA gauge available for reference on the instrument panel. Pages of discussion on that, as I am sure you recall, over the course of the BEA "reveal" process and on the competing philosophy of what to do with the precious square feet of display area available to the crew.

Someone posted this further, up, IIRC bubbers.
The captain that can hand fly comes up in the last minute and sees something he has seen before.
Full stall, full back side stick and it is too late.
I don't know if it was too late at that point or not.
What the crucial moment was that would have allowed a nose down, restore airspeed, unstall, recover via pullout at an altitude of > 1.0 feet has been calculated by some sharper folks than me. A best guess. It may have been past that point that Captain Dubois arrived, or it may have been X seconds previous.

I question whether or not he'd "seen that before" in an A330.

My rejoinder to you is due to the general point that A330 full stall practice isn't in the training regime (based on 2-3 years of discussions on this). Thus, "stall it to get various data points" was not done during development since it is not a cert requirement. (Probably).
Until the AF 447 crew became test pilots unwillingly, some of the stall and post stall characteristics of an A330 were unknown.

How do you train someone (Captain Dubois) when the info to train him with doesn't exist? Further that lack of data points, the flight sims can't be soundly programmed to give "what it does when stalled" training.

This leaves any pilot, not just Captain Dubois, lacking a chance to be in a full stall situation in a training scenario. Granted, stall prevention is the general training focus, for good and valid reasons.

To sum up: I don't think he'd "seen that before" and thus was playing catch up from the moment he entered the cockpit. Had what he saw, as you suggest, been something he recognized as a stalled A330 -- something "he'd seen before" -- my estimate is that he'd have directed Bonin to make stall recovery control inputs rather than the directions he did give him.

It is also my estimate that CVR transcripts would have included some rather forceful language, to include such bon mots as "merde, we're stalled, get the &$^# nose down!" or words to that effect.

That's an estimate, and we can't ever know.

Lyman

4th Mar 2013, 14:56

AoA can be derived, that too was discussed, ad nauseum. But if only PITCH (assiette), in all its extreme iterations, NOT ONE WORD?

Upon the first reading of the CVR, some Press released a comment from DuBois, as he entered the cockpit, (He had heard the STALLWARN, briefly).

"This is STALL, get the NOSE DOWN"....It disappeared from the public domain, and I cannot find it here in the earliest threads.

No word from BEA, only an abbreviated and "approved" version.

"We have lost all control"....PITCH too? No discussion of controls that continue to function.

I do not know if my conclusions make my sanity suspect, but from the very first, I have not trusted the way the discussion "evolved" to competely blame the pilots.

As a pilot, I will always doubt the slam dunk nature of the comdemnation that clouds the professionalism of this flghtcrew.

Does that mean BEA have published lies? Perhaps, but for now, it is not necessary to believe they lie.

Only that they are quiet, and sit on the only possibility of exoneration.

That's unacceptable....

thanks for your response, LW

DozyWannabe

4th Mar 2013, 14:58

That has to be seen - NU inputs are effective no doubt but the THS does not collaborate ... Maybe they still go to the stall ... but that's not that easy ... and that's not that easy to maintain ...

I repeat the question; Even if such an experiment were done and your supposition were correct - which it may well be - what practical difference does it make?

It certainly would not constitute a case for changing the design and operation of autotrim in Alternate Law for the reasons I stated above.

CONF iture

4th Mar 2013, 15:14

It certainly would not constitute a case for changing the design and operation of autotrim in Alternate Law for the reasons I stated above.
Why not correcting something that is stupid : auto trimming to the point of stall and further into it - Let a pilot take such deadly initiative, don't do it for him.

DozyWannabe

4th Mar 2013, 15:17

It won't do anything unless the pilot asks it to though!

Lonewolf_50

4th Mar 2013, 15:46

Lyman:

I see what you were pointing to a bit more clearly. Just a few extracts from the CVR from some verbal exchanges early on:
(Note: relevant CVR inputs are from after the event began, which was about 2:10:06) (PL & PR = seat position)

PL : Watch your speed Watch your speed
PR: ok ok ok I'm going back down
PL: According to the three you're going up, so you go back down
PL: You're at ... go back down

As you point out, identifying a problem with pitch is not recorded. Just for interest, added time tags to some subsequent references .... many left out ...

PR 2:10:49
We're in yeah we're in climb
PR 2 h 11 32
I no longer have control of the plane; I no longer have any control at all of the plane
CAP 2 h 11 min 43
what are you doing?

in the next half a minute, various points comments, actions ... then ...

CAP 2:12:15-19
I don't know we're going down
My read on this was there is a pause between "I don't know" and "we're going down"

The Captain sees descent on the instruments and verbally notifies his crew of that condition.

In the next minute, for whatever discussion and control input went on, and as we've discussed numerous times before, a correction to the person at the controls (PR) to do something with pitch is not recorded.

PR 2:13:25
What is... how come we're continuing to descend so fast?

Reference to pitch is made late in the event, though the point seems to be well after a successful recovery (unstall, pull out, climb ..) could have been initiated and achieved

2:13:40
CAP: No no no don't climb back up
PL: Go down, then
2:13:45
PL: Go give the me controls. The controls to me.
PR: Go on, you have the controls. We're still in TOGA, ok
2:14:05
CAP: Watch it, you're pitching up <-----------------
PL: I'm pitching up? <-----------------
PR: Well, we should, we're at 4,000 feet
2:14:18
CAP: Go on, pull

It ends shortly after that. (In tears :( )

gums

4th Mar 2013, 15:59

Ahhhhhh..... back to the control law logic and implementation.

From Doze:
It won't do anything unless the pilot asks it to though!

I don't think that's entirely accurate.

Best I can tell from the reversion sequence, the "autotrim" for the THS is in effect until in DIRECT law ( or maybe sub-law 2 (c) iv /sarc off). So the system will attempt to achieve 1 gee corrected for pitch attitude. Have I read that wrong? And I also see an implementation that trims the THS in order to reduce the stick inputs required to maintain the gee required to maintain the previously commanded pitch attitude. NOT A PURE ATTITUDE HOLD mode many of us were used to in A/P -assisted modes.

So relaxing stick with a positive pitch attitude would "normally" result in increasing THS until the AoA functions kick in. Their "mode" didn't have the AoA "protections", if I read that law correctly.

I must agree that manually flying a basic jet at high altitude and a mach near 0.85M is not nearly as benign as the same IAS at 15,000 or 20,000 feet. That mach doofer causes some strange things, and your TAS is much higher so you muct be gentle and use measured inputs. So being a low altitude glider pilot may not satisfy the criteria.

Still a sad, sad example of airmanship and systems knowledge and crew coordination.

Lyman

4th Mar 2013, 16:29

LW

PL : Watch your speed Watch your speed
PR: ok ok ok I'm going back down
PL: According to the three you're going up, so you go back down
PL: You're at ... go back down

The Three? ASI. This is about velocity, not attitude, or altitude. This would be expected with UAS, speeds being misleading, depending on rate and simultaneity of ICE blockages....

It also clearly tells us that the crew are not cognizant of UAS; if they were, they would not be so alerted to a needed correction......they would mistrust the speeds.... not act on them.

It also sets the tone for the throttle obsession PF demonstrated on the way up...

He is seeking a speed to settle on, not a PITCH. He does not tumble to PITCH until later on....

from gums...

So relaxing stick with a positive pitch attitude would "normally" result in increasing THS until the AoA functions kick in. Their "mode" didn't have the AoA "protections", if I read that law correctly.

This crew, but especially PF Bonin, was not madly pulling on the stick from the loss of A/P, not at all. PITCH increased incrementally, and PF was not cognizant of its dangerous trend, each time he relaxed, he felt one gee...even when increasing, it was seemingly "benign"....

His "I have no control of the plane..." happened after the THS migrated to essentially full (-)....

That does not explain his lack of concern with the Attitude increase, but he was focused on speed, and Roll....

I will repeat myself for the umpteenth time, this crash started with a vengeance at loss of speeds, not with "Full aft Stick"....

We are not certain at all the crew was aware of UAS until 2:10:22, sixteen seconds after loss of a/p. By that time, and imo, the die was cast. After STALL, it's all jelly beans, and pub blather.

EDIT LONEWOLF

In the next minute, for whatever discussion and control input went on, and as we've discussed numerous times before, a correction to the person at the controls (PR) to do something with pitch is not recorded.

You and I do not know if it was recorded, or not. Only BEA know that, and they are not saying....

DozyWannabe

4th Mar 2013, 17:29

I don't think that's entirely accurate.

I guess it depends on how the phrase is interpreted. Commanding a pitch attitude with the stick will cause autotrim to maintain the pitch attitude at the point the stick was released to the best of its ability.

Best I can tell from the reversion sequence, the "autotrim" for the THS is in effect until in DIRECT law ( or maybe sub-law 2 (c) iv /sarc off).

Put more simply, autotrim is active in all laws and sub-laws except Direct (and MAN PITCH TRIM ONLY).

So relaxing stick with a positive pitch attitude would "normally" result in increasing THS until the AoA functions kick in.

Releasing the stick effectively commands attitude in Normal Law and all modes of Alternate. Releasing at a given pitch attitude will cause the flight control logic to gradually release the elevator demand used to acquire that pitch attitude as the trim takes up the slack.

It's different to other implementations, but in terms of airliner ops it makes sense. The fact that it works cannot be denied.

gums

4th Mar 2013, 17:49

Salute!

TNX, Doze for confirming my understanding of the THS.

However, the big point I have trying to make for 2 years is that the flight control laws for the 'bus use the basic gee command, but corrected for the pitch attitude.

Releasing the stick effectively commands attitude in Normal Law and all modes of Alternate. Releasing at a given pitch attitude will cause the flight control logic to gradually release the elevator demand used to acquire that pitch attitude as the trim takes up the slack.

The biggie is "effectively commands attitude". In other words, it will use 0.87 Nz at a pitch attitude of 30 degrees. So without increasing power, the speed/AoA changes and the THS keeps on keeping on to maintain the 30 deg pitch attitude until the jet reaches the AoA protections - HANDS OFF!!. This has an insidious effect, as "normal" jets would require more and more back-stick to maintain the attitude due to increasing AoA as it slows down. Again, I must remind all that our first FBW system was a blend of AoA and Nz. So we noticed that we had full back stick and nothing was happening with the nose once we hit the AoA limit for that gee. At max AoA, we were one Nz gee command.

PJ2

4th Mar 2013, 17:58

Hi Lyman;

Re your observation in Post #816 that, "AoA can be derived, . . ."

Hm, I don't think so. I'm not an aeronautical engineer but how can AoA be "derived"?

Lonewolf_50;

Re, "How do you train someone (Captain Dubois) when the info to train him with doesn't exist? Further that lack of data points, the flight sims can't be soundly programmed to give "what it does when stalled" training."

It is true that approach-to-stall recovery training isn't the same as training to get a transport aircraft out of a stall. However the guidance in FCTMs is clear, that a high descent rate that cannot be arrested indicates that the aircraft is stalled and the AoA must be reduced.

"This leaves any pilot, not just Captain Dubois, lacking a chance to be in a full stall situation in a training scenario. Granted, stall prevention is the general training focus, for good and valid reasons."

While there is little to no actual flight data on aircraft behaviour in a full stall, that does not mean that the simulator is demonstrating entirely and completely unreliable or incorrect behaviour. The degree to which behaviour is or isn't replicated may be more apparent to engineers than to pilots who must recover the airplane. What I'm saying here is, I think an A330 Level D simulator is useful and not irrelevant. Airbus and the BEA must have thought so because they replicated AF447 and in the Final Report even drew graphs in comparison with AF447's flight data.

What was missing in AF447 was the acceptance that the airplane was stalled, and the knowledge and/or comprehension that the wing must be unloaded, the AoA reduced in order to recover, and that for this to occur the only way is to point the nose down.

Re, (my bolding), "To sum up: I don't think he'd "seen that before" and thus was playing catch up from the moment he entered the cockpit. Had what he saw, as you suggest, been something he recognized as a stalled A330 -- something "he'd seen before" -- my estimate is that he'd have directed Bonin to make stall recovery control inputs rather than the directions he did give him."

Yes, I agree with you on all points. Given a full understanding of the problem (the stall), it's what flight crews would do. The puzzle is in why an altimeter reducing by a thousand feet every 3 seconds while the nose was pointed up, didn't register and that fact is purely for hindsight speculation.

Re, "It is also my estimate that CVR transcripts would have included some rather forceful language, to include such bon mots as "merde, we're stalled, get the &$^# nose down!" or words to that effect."

Yes, I have to agree that's how someone would say it!

Dozy;

Quote:
Originally Posted by Machinbird http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/buttons/viewpost.gif (http://www.pprune.org/tech-log/493472-af-447-thread-no-10-a-41.html#post7724567)
Generations of pilots learned to fly smoothly by a proper use of the trim controls. The Airbus architecture minimizes the value of this skill...

"Well yes, but that doesn't make the Airbus FBW system bad, dangerous or worse than anything else - it's just an iterative example of how technology has changed. I don't mean to sound disrespectful, but isn't there a hint of 'why can't they just do it the old-fashioned way' about that point?"It is neither practically nor philosophically merely just an "iterative example of how technology has changed." It is a far more complex human phenomenon that requires the respect of awareness. Technology changes who we are and if we are blind to that, we are blind to its dangers while lauding its benefits.

That said, I should have thought the reason obvious; - because the old-fashioned way worked and saves lives on occasions when technology gives up and hands a mess over to the human pilot who can competently, safely take over and live to enter the snag in the log book.

You already know I have no problem with automation and all technological advances just so long as one knows one's craft and can do the job when the bytes and pixels quit - in other words, one is competent at one's job as a pilot and never lets anyone think that technology should be respected. Understood, yes!, but never respected and that means knowing how to fly and think regardless of technology.

DozyWannabe

4th Mar 2013, 18:00

The biggie is "effectively commands attitude". In other words, it will use 0.87 Nz at a pitch attitude of 30 degrees. So without increasing power, the speed/AoA changes and the THS keeps on keeping on to maintain the 30 deg pitch attitude until the jet reaches the AoA protections - HANDS OFF!!.

Well yes, but that's exactly what it's supposed to do, and pilots converting to the FBW Airbus series are trained on that aspect of the behaviour.

This has an insidious effect, as "normal" jets would require more and more back-stick to maintain the attitude due to increasing AoA as it slows down.

I don't know if "insidious" is the right word, as the behaviour is drilled into pilot training from the start. From a piloting perspective it's essentially "point and forget", and it applies whether commanding positive pitch, negative pitch or levelling off.

It's undoubtedly an aspect that's different than what went before, but time has shown that it's simple, reliable and works just fine.

Again, I must remind all that our first FBW system was a blend of AoA and Nz. So we noticed that we had full back stick and nothing was happening with the nose once we hit the AoA limit for that gee. At max AoA, we were one Nz gee command.

Which makes sense for a fighter. Engineering 101 - use the right tool for the right job!

Hi PJ2, and regards!

It is neither practically nor philosophically merely just an "iterative example of how technology has changed."

To be certain, I was referring only to the autotrim function on the FBW Airbus system - no other aspect of it.

That said, I should have thought the reason obvious; - because the old-fashioned way worked and saves lives on occasions when technology gives up and hands a mess over to the human pilot who can competently, safely take over and live to enter the snag in the log book.

Agreed totally. However to the best of my knowledge the autotrim system in and of itself has never given up and handed a mess to the pilot.

...never lets anyone think that technology should be respected. Understood, yes!, but never respected and that means knowing how to fly and think regardless of technology.

*Now* we're into philosophy. To respect someone or something is not to say one should automatically defer to that which is being respected.

Conversely when an argument is made that technology should not be respected, following that path runs the risk of negating one of the biggest motivators for wanting to understand something, does it not? In my experience, learning and understanding a subject becomes much easier and more rewarding if respect for and interest in that subject already exists.

Lonewolf_50

4th Mar 2013, 19:27

gums:
... maybe sub-law 2 (c) iv
I think that the Left Seat Pilot activated that, by calling the Captain. :}:(

Lyman:
The Three? ASI. This is about velocity, not attitude, or altitude. This would be expected with UAS, speeds being misleading, depending on rate and simultaneity of ICE blockages.
Lyman, I am not so sure about that.

PL: According to the three you're going up, so you go back down

I'd say, within the context of that passage, the gent in the left seat was referring to ALTITUDE and CLIMB, since SPEED display systems at this point weren't showing any useful information.

They were in UAS at the time, so there was no good info according to the three ASIs then available to them. Does my reasoning make sense to you?

Three being VSI, altimeter, and something related to the FD. (And I may be utterly wrong.)

PJ2:
However the guidance in FCTMs is clear, that a high descent rate that cannot be arrested indicates that the aircraft is stalled and the AoA must be reduced.
The temptation for me to run yet again down that rat hole of "why no AoA gauge in the cockpit?" shall be resisted. :E

What I'm saying here is, I think an A330 Level D simulator is useful and not irrelevant. Airbus and the BEA must have thought so because they replicated AF447 and in the Final Report even drew graphs in comparison with AF447's flight data.
Roger. Perhaps at the very least this can be grown into at least some procedural training for future crews? We shall see. The original simulators I flew for instrument training some three decades ago were hardly Level D sims, but I sure got graded on my instrument flying in them anyway. Some training was indeed achieved, though I got no style points.

Thanks for the course correction, PJ2. As usual, a pleasure. :cool:

PJ2

4th Mar 2013, 20:01

Regards, Dozy;
To be certain, I was referring only to the autotrim function on the FBW Airbus system - no other aspect of it."The old-fashioned way" then being just a reference to the way trim is handled - okay thanks for your clarification - I hadn't read carefully enough. In other words, use the pickle-switches...manually trim all the time when one is manually flying.

Yes, I'd probably agree with the requirement when manually flying as trimming was one tactical feedback loop that I do recall on the Boeings, Douglases and Lockheeds. At the same time, I don't recall it being a transition or operational problem on the A320.

Now I never went back to manual trim airplanes so can't speak for that direction of a transition.

I wonder if the B787 is full-time auto-trim...can't recall at the moment.
However to the best of my knowledge the autotrim system in and of itself has never given up and handed a mess to the pilot.No the system hasn't by itself handed over a mess, that's an autoflight function :) and of course the comment therefore doesn't apply.

Bit OT, but "respect" means trust and belief in reliability and integrity of that which one grants one's respect. That has nothing to do with interest in and / or understanding something although for some it may be a motivator. I do not and never will trust technology per se and do not unconditionally believe in it or its nature but I use it every day and for the most part understand the simpler bits within a consumer's competency.

LW;
Perhaps at the very least this can be grown into at least some procedural training for future crews? We shall see. The original simulators I flew for instrument training some three decades ago were hardly Level D sims, but I sure got graded on my instrument flying in them anyway. Some training was indeed achieved, though I got no style points. LOL...I can assure you that a Level D sim doesn't make it look any more stylish...

Yes, I agree, I think there is a definite training advantage to seeing 15deg ND and a descent rate of 15,000fpm if only to realize that it (in extreme circumstances, much the same as other unusual attitudes), may be necessary and it doesn't break the airplane. If one is in a corner, I think overspeeding the airframe is preferable to stalling it.

There are some thoughts that recovery from this stall was possible even below FL150 had the wing been aggressively unloaded and the AoA reduced. Up higher it took about 40". Down lower I'd hazard a guess that it would take a lot less time and therefore altitude, (thicker air). The elevators were effective in the sim all the way down even against a -13deg THS, and it always wound towards the ND position with steady ND SS. The FPA would have been available at that time on this flight (IIRC) and could have shown them the descent angle. But by that time, the stick and the elevators were almost continuously full-up.

gums

4th Mar 2013, 21:38

Hail, hail the gangs all here!

DOZE!!! I still don't think you understand my point about the insidious effect of the 'bus autotrim WRT the gee command and pitch attitude.

Well yes, but that's exactly what it's supposed to do, and pilots converting to the FBW Airbus series are trained on that aspect of the behaviour.

I don't know if "insidious" is the right word, as the behaviour is drilled into pilot training from the start. From a piloting perspective it's essentially "point and forget", and it applies whether commanding positive pitch, negative pitch or levelling off.

It's undoubtedly an aspect that's different than what went before, but time has shown that it's simple, reliable and works just fine.

Gotta tellya, that if the AF447 crew had a gut understanding of the system, we wouldn't all be here talking about it.

I still see 'bus drivers talking about "commanding" a pitch attitude. WRONG! They command a gee and when reaching desired pitch they release the stick and the THS "autotrims" to maintain the gee for that pitch attitude. In the 'bus, these are very small pitch attitude changes and nothing like the ones we commanded in the Viper. I will grant you that. But basic aero and the controls law prevail. I am not all that sure that the basic 'bus driver understands that.

Up to me, I would demo the control laws down at 15,000 feet or so to eliminate mach effects. Pull up to 10 degrees and watch the trim wheel move as you relax the stick to hold that attitude. Hmmmm. Wait until the AoA protection displays and such kick in and let'er rip! Nose goes down and commanded gee changes, etc. etc.

No need to do a no sierra approach to stall, as the AoA protection limits seem very conservative to me when looking at the manuals.

In the Viper, we would demo the autotrim and have Joe Baggodonuts look back and observe our "THS". Pull up and relax the stick. Eventually get to the AoA limit and see the tail moving more and more until it was commanding full nose down. We commanded trim gee that was not corrected for pitch attitude like the 'bus.

@ PJ

In wings level flight, AoA can be derived from the pitch and the inertial velocity vector regardless of the air data probes/cones. The Sluf and Viper HUD had a "zero sight line" cross, and usually the flight path marker ( FPM) was below it ( negative gees was something else, heh heh). That was your AoA in wings level flight.

I'll still maintain that a HUD with the FPM displayed WRT pitch lines would have provided a big clue as to what was happening. The doggone thing shows exactly where the jet is going without regard for airspeed, altitude, attitude, roll angle, gee, AoA, ad nauseum. Also neat for final approach in crappy weather.

With back stick, the pilot would have seen decreasing FPM angle and moved the stick forward well before the AoA alarms went on. In other words, it would have been like looking out the windshield in daytime, CAVU, with nice scenery in front.

I am still disappointed that many think the 'bus stick commands a pitch attitude and not a small delta in the gee command to reach the desired pitch.

bubbers44

5th Mar 2013, 00:01

Can we not see the copilots pulled up into a 11 degree nose up attitude that obviously would stall the airplane. Then they held back SS to maintain the stall until impact with the ocean. No pilots I know would do this so why did they do it?

CONF iture

5th Mar 2013, 00:03

It won't do anything unless the pilot asks it to though!
It could do just that - Hands off - Try to maintain 1g
Will cease at alpha prot in Normal Law but will go all the way In AF447 Law ... Find the logic ?

bubbers44

5th Mar 2013, 00:13

I think I know but Airbus training needs to include how degrading automation needs to let people understand the level of automation they are at.

mm43

5th Mar 2013, 06:07

I think I know but Airbus training needs to include how degrading automation needs to let people understand the level of automation they are at.That's the crux of the problem! What can anyone do when -
1.. They are told they are in ALT Law,
2.. Know the A/THR has disconnected, and
3.. Pull back on the SS, and with
4.. Stall Warning ring in their ears, they
5.. Do nothing right!

It may well all be put down to lack of appropriate training, but even then, "You can lead a horse to water, ... but?"

HazelNuts39

5th Mar 2013, 08:36

Just an analogy:

The FCOM says about High Angle of Attack Protection:
Under normal law, when angle of attack becomes greater than alpha-prot, the system switches the elevator control from normal mode to a protection mode in which the angle of attack is proportional to the sidestick deflection. (...) If the pilot releases the sidestick the angle of attack returns to alpha-prot and stays there. (...) To leave the angle of attack protection the sidestick must be pushed (...) forward.When I first read that, I just thought - well, that's logical, and went on reading. Prior to the two incidents, I never realized that, when this happens in cruise and the SS is not pushed forward, the airplane zooms up 3000 ft.

I don't think AF447 will happen again - until everyone has forgotten all about it.

P.S.
Had the pilots of the AF 'level bust' incident been told about the THY incident?

Lyman

5th Mar 2013, 10:27

HazelNuts39

(...) If the pilot releases the sidestick the angle of attack returns to alpha-prot and stays there. (...) To leave the angle of attack protection the sidestick must be pushed (...) forward.

For how long does the AoA "stay there"? (Alpha Protection) what does it take to gain Nose Down?

"Push the stick forward"?
How far forward? Does THS freeze, or ennable the protection?

At the outset, just after loss of auto, Bonin commanded a climb. Two seconds later... "STALLWARN.....cricket, cricket, Master Caution......" and from Robert, "What was THAT?.....". Was he referring to the SW, or to BUFFET? That would qualify an exceedance of Alpha Prot, especially with an assistance from WindShear? (updraft). Is this the reason Pitch remains in gee? ALII (b)?

I think I read here that forward stick must be fully forward, something we do not see from Bonin? Once discouraged from applying forward stick by the recurrence of inappropriate STALL warn, would he desist from further attempts?

How does THY pertain to 447?

HazelNuts39

5th Mar 2013, 10:51

Lyman,

you're mixing things up. The FCC's weren't in normal law when Bonin took the controls. You miss the point of my post, which is about learning.

Lyman

5th Mar 2013, 13:18

Howdy...

For purposes of discussion, say A/P had dropped, and the aircraft had remained in NORMAL LAW. Is this same circumstance then also possible? Is this protection available in ALII (b) ? Or, only "g prot" ? The "G" had reached +1.65 in the climb, at (prior to) 7000 FPM .......

Is it possible for this Aircraft AoA to exceed Alpha Prot in Auto?

One last, for now, What is the possibility that PF believed the aircraft had remained in NORMAL LAW until he heard his mate declare at 2:10:22: "Lost speeds, Alternate Law..." ??

Any possibility? If not, what was his alert to LAW change?

AlphaZuluRomeo

5th Mar 2013, 15:26

HazelNuts39

5th Mar 2013, 16:31

Lyman,

I'm somewhat reluctant to reply to your questions, because the 'level bust' incidents have been discussed at length in various threads and have no relation to AF 447.

Since the High AoA protection is not available in ALT 2b. it can only occur if the airplane remains in Normal law.

Yes, it is possible for AoA to exceed Alpha Prot in Auto. IIRC that occurred in the Turkish level bust due to turbulence. The AP disconnects when that occurs.

Your last question - if the PF failed to notice the indications on the PFD and ECAM and did not hear the PNF's announcement, it is possible he was not aware of the law change.

Lonewolf_50

5th Mar 2013, 16:31

AZR:
merci beaucoup (You are making me blush! :O:O)

Hazelnuts39:
I don't think AF447 will happen again - until everyone has forgotten all about it.
I hate to agree with that, but I must agree based on the last century of manned flight. :(

PJ2

5th Mar 2013, 17:09

hi gums;
Yes, the gang's all here, but only momentarily!In wings level flight, AoA can be derived from the pitch and the inertial velocity vector regardless of the air data probes/cones. The Sluf and Viper HUD had a "zero sight line" cross, and usually the flight path marker ( FPM) was below it ( negative gees was something else, heh heh). That was your AoA in wings level flight.Yes, I understand that, we've discussed that and I even had posted a schematic showing how AoA can be roughly approximated (while not precisely and not instantly due to lag but perhaps usefully if one is trained / skilled at such interpretation*) from the FPM / FPV and pitch angle, independent of the AoA sensors.

"Derived" in flight data work means usefully accurate and precise as well as timely and the FPM / FPV vs pitch method of "deriving AoA" in rapidly changing circumstances, is none of these.

While the FPM/FPV display is inertially-driven this still requires a working ADR (AF447s were intermittent and, in the time period available, essentially unusable) and a working AoA sensor (Perpignan, frozen sensor, erroneous stall speed display on the PFD).

The point I wished to make in regard to Lyman's statement that AoA can be derived is that it can't be in the sense that it could be used to display AoA when original sources as described, are not available.

*When the A320 first came online, we were trained that the FPV Flight Director should not be used as guidance during a go-around because of the lag in the FPV as the aircraft stops descent and begins the climb. The justification was, following a lagging display could lead to reduced climb performance. I believe that's now changed and the normal FDs are displayed automatically when the thrust levers are pushed to the TO/GA detent.

PJ2

5th Mar 2013, 17:31

Of possible interest is the UAS table below from the A320, dated April, 1991. The table clearly provides pitch and power settings for all regimes of flight. This checklist is in contrast with what I think was and is a confusing UAS memorized drill & checklist combo. While the origins of the present mess of a drill / checklist are understandable (post Birgenair & Aeroperu), compared to this simple checklist which provides clear information on pitch/power settings for all flight regimes, the present drill remains open to interpretation as to when the safety of the flight is at risk. The present drill also requires a pitch change in cruise altitude when none is required.

While pulling a transport aircraft up to 10deg pitch while in cruise is a serious error, I think the memorized drill, if taught incorrectly or misunderstood (and it still isn't clear) can leave some pilots who may not get into the books very much, (as per DP Davies' thoughts posted earlier on 'working at the career' and learning) or otherwise just thinking about the drill and maybe asking questions, with the impression that "pulling up" somehow solves the 'problem'. Granted a 5deg pitch up at FL350 won't lead to stalling the airplane, but why destabilize the airplane in the first place?

http://www.smugmug.com/photos/i-bgcKZkd/0/X3/i-bgcKZkd-X3.jpg

Chris Scott

5th Mar 2013, 18:49

Hi gums,

Quote from gums #829:
"In wings level flight, AoA can be derived from the pitch and the inertial velocity vector regardless of the air data probes/cones. The Sluf and Viper HUD had a "zero sight line" cross, and usually the flight path marker ( FPM) was below it ( negative gees was something else, heh heh). That was your AoA in wings level flight."

Three years ago (before you joined this discussion?), some of the "gang" chewed over this subject, and we gradually realised that - for various reasons - it wasn't as simple as we had hoped...

http://www.pprune.org/tech-log/395105-af-447-search-resume-26.html#post5575204

Mac the Knife

5th Mar 2013, 18:52

:uhoh:

Wouldn't their Attitude Indicator showing a lot of blue sky given them a clue?

Just asking!

:bored:

Lonewolf_50

5th Mar 2013, 20:21

Presuming the AI was integrated into a working instrument scan, yes.

Lyman

5th Mar 2013, 20:37

PJ2

Howdy....From Chris Scott, post #521, "Search to Resume"

As CONF iture knows well, a good ball-park indication, without any actual numbers, is on the PFD in FPA mode (preferably with the FD switched off). The Pitch attitude angle minus (algebraically) the flight-path angle approximates the AoA. For non-Airbus pilots, the latter is indicated by the "bird" symbol. The snag, for this purpose, is that it also shows any drift in azimuth. So, when there is a lot of drift, it is not directly under the little black box* which represents the nose of the aeroplane.

This is what I had in mind, and I recall the flightcrew doing some things in the cockpit that put me in mind of wanting the "Bird"...... for AoA? Dunno...

So sorry to get gums in the soup....took some looking.

PJ2

5th Mar 2013, 21:05

Hi Lyman;

Yes, that's what I'd figured was in mind as I know AoA can't be derived from any other flight or system parameters.

I do think that someone "tuned in" to his/her airplane could make use of this information so in that sense it's another tool, subtle and not widely nor well-understood even in the instructing world, (in fact I know an airline that refused to authorize use of the FPV/FD and would not train or permit its use in operations).

I think had they had the FPV they would have seen this, (quickly...time yourselves... 3, 5, 10 seconds with noise, buffeting, warnings and fright, what's the AoA? What angle are we going down at? Should I pull or push?):

http://www.smugmug.com/photos/i-8Mjv5cF/0/XL/i-8Mjv5cF-XL.jpg

bubbers44

5th Mar 2013, 21:20

2 degrees nose up attitude and cruise power would have made this accident a non event. Hopefully pilots will now not make the same m
istake they did.

Lyman

5th Mar 2013, 21:35

Once I jump, I PULL, the ripcord.....20000fpm descent, AoA +45, Pitch 8 ND.

Nope that's wrong, badly..... seven seconds. Adios.

Is this our friends?

gums

5th Mar 2013, 22:24

TNX Chris and PJ for getting me back to Earth.

I realize that we had the AoA discussion way back before I started to comment, but I had read the threads with only one comment until after we saw the wreckage pattern and got into control laws and a deeply stall jet.

As several had pointed out, a derived AoA might be possible but impractible, and prolly unuseable if the pilot wasn't used to using AoA on a dail basis as Mach did coming aboard the boat.

As far as the FPV, it would likely be updated at a decent rate - maybe 50 or 60 times a second, same as the digital attitude display. The inertial velocities must be sampled at a healthy rate or your nav errors are off the chart. EDITORIAL NOTE: The current use of GPS is super, but I can see less maintenance and care for the "good old inertial" units. But back to the chase - if you are pulling and that FPV ain't moving the same direction as the stick, then you are in a heap of trouble. This is much easier to see in a HUD, as the pitch lines are "real world' and you can only see about 15 degrees total from top to bottom. However, they were extremely helpful maintaining a 3 deg descent angle or any angle you wished. A PAR was so easy it felt like cheating.

PJ2

6th Mar 2013, 00:17

gums;

Re, "A PAR was so easy it felt like cheating." :ok:

Yessir, done them very occasionally in the DC9. Aside from Canarsies onto 31R, that was a leg to get!

I must be out to lunch as I never realized you weren't on earth all the time! The reminder re 'derived' etc was a good one and it got me going too.

bubbers;

Re, "I think I know but Airbus training needs to include how degrading automation needs to let people understand the level of automation they are at."

I trained on the A320 in 1992, the A340 in '99, the A330 a bit later and from the get-go all three laws as well as the protections were heavily emphasized, taught, practiced and checked in recurrent rides. We knew that in Alternate and Direct laws one didn't do anything rash, quickly or rough with the airplane. While it was complicated sometimes, the ECAM was / is very good and must always be done to completion. Forgive me but really, the people who do this work aren't dull or slow.

Re, "2 degrees nose up attitude and cruise power would have made this accident a non event." Well, QED. That's about what the airplane cruises at. Monitor altitude, set power, wait, do the ECAM, get out the QRH. That's why I said very early on, "do nothing, wait..." It's not an emergency.

Regarding pitch, two to 2.5deg NU is the pitch the A330 cruises at and the thrust is already in the CLB detent, so the airplane is immediately both stable and under control which is the first rule, 'aviate'. To change the pitch attitude, (arbitrarily or via the checklist), adds workload and increases the potential for loss of SA as one departs one's cleared altitude and minds the speed, heading, etc and it delays getting on with the ECAM while the PF is ensuring that the airplane remains under control. I surmise that these are the things check airmen argue about in meetings all the time. In my view the UAS drill and checklist is a mess and can, if improperly understood and taught or badly executed, reduce and not increase flight safety.

One thing to note that those who fly these airplanes may not know is, a transport airplane can depart controlled flight very gently almost languidly and smoothly, without broadcasting what it's doing. In the departure from controlled flight into a severe loss of control there was nothing violent about this accident. Even the descent would have been "languid" in terms of pitch, roll, yaw, gee despite the buffeting.

As you must know instinctively from experience, it isn't 10 or 15deg NU that would get the attention of a transport crew, it is a degree or two above nominal. So if the airplane is in stable, level cruise at 2 deg, then a pilot taking it to 3 to 5 degrees (yielding about a 1000 to 1500fpm climb), and keeping it there would require an immediate taking of control to stop a loss of control event and also regain the cleared altitude. Seven or eight degrees pitch at cruise altitude and Mach is positively frightening in my book.

When the ATs disconnect, you'd have to bring the levers back a bit to maintain the previous cruise setting but you'd never overspeed the airplane if you left the TL's alone.

Lyman;

Re, "Is this our friends?"

I don't know. I don't know why this happened. All we know is a bit of how.

HN39;

Re, "Yes, it is possible for AoA to exceed Alpha Prot in Auto."

Absolutely correct. Ask any carrier flying into Mexico City in an A320 about the sharp left turn onto the 5's from the 160R of SMO with the speed right back, landing flap out and an encounter with a bit of turbulence in the turn. It will also occur if one retracts the flaps too early, AP on or off.

3holelover

6th Mar 2013, 01:12

PJ....
Re: your last image and questions (rhetorical though they might have been): AoA- about 23 degrees, going down at about 35 degrees and you should bleeding well push!... ?

Have I understood the display correctly? ( I don't fly, obviously)

CONF iture

6th Mar 2013, 01:54

As one image (http://www.pprune.org/7727725-post847.html) cancel the STALL Warning, temptation to pull can be strong, especially as indicated airspeed is increasing ... Suppose you was already pushing hard at this time.
Note how the big red chevrons do suggest me to pull too ...

bubbers44

6th Mar 2013, 03:28

Mexico City has the only approach I have ever seen that intercepts the localizier at more than 90 degrees. Also the automation will level you off above the glide slope so you have to TF the altitude to not be high. Trick :mad: for those curious. Also they clear you for this long arrival then turn you in short so if you don't know about it you are way too high so have to speed brake the whole arrival.

Clandestino

6th Mar 2013, 12:01

How in the world did you manage to resurrect this zombie thread again?

I started to read final report, but it is very massive text, and it takes a lot of time to read it.Massive it might be, yet it is very succinct with not much duplication or garish. Complex area, such as aviation, can not be explained in simple terms.

When the plane reverted to Alternate Law (2B if I remember correctly), engaging the autopilot was not an option. Once latched into alternate law, the autopilot can not be reengaged until the system is reset on the ground.

Thx for the AP answers. So, AP switching on was not an option at all. It was also technicaly impossible.

False. Once speeds return back to normal, AP is available even as alternate law remains latched for the remainder of the flight. Pages 85 and 86 of the English edition of the final report refer.

Of course, once aeroplane was stalled, turning on the AP was impossible and pretty pointless.

I want to hear something from the people who are also pilots, to hear what were they PROBABLY thinkProbably nothing at all. Control inputs and cockpit audio bear no trace of anything that suggest the presence of rationality. They were panic stricken.

After that they were "mad" and try to put the nose down, as I understand.No. CM2 kept pulling, First significant input on the left stick was recorded merely 45 seconds before splashdown. CM1 pushed a bit but was counteracted by CM2. After that CM1 started pulling too and reversed to push in a final few seconds.

jcjeant, being afflicted by fear or mental anguish is irrelevant if the problem was dying, don't you think?What the... for Finnegan's sake, have a look at the CM2 stick trace! That's made by a guy who believed he would die if he just lets go of the stick! Such accidents are with us ever since the aeroplanes were first stalled! With all the emphasis in Airbus discussions being on autoflight and FBW, folks tend to forget effing Airbus is still an aeroplane, it stalls if you go over alpha crit!

why with several nose-down inputs to the control stick, some lasting several seconds, why the elevators never moved into a nose-down position. They moved away from full nose up, which was enough to reduce pitch and promptly provoke another pull to backstop from CM2.

. I've asked that question a couple of times and no one seems to knowIt was answered more than a dozen times in 10 threads. Pity some folks could not understand or did not want to understand as it didn't fit their pet theories.

So even though the pilot commands nose-down, the fly-by-wire never moved the elevators to a nose-down position...for 15 seconds!!! Pilot did, pilots didn't. Two sticks - two traces.

The fact that the other pilot cannot know what input is being made and therefore cannot make correct assessments as to aircraft handling is the reason why dual inputs are prohibited.My gang also prohibited them on 737, ATR, MD-80 and Q400 also stipulated that only one pilot can be at the controls at the time, be it left, right or auto. Wonder why is that. :E

They were obviously flying thru the storm, why they didn't go around it?

But the aeroplane had not encountered, before or during the accident, an exceptional meteorological situation from the point of view of phenomena that are traditionally avoided in stormy environments (turbulence,lightning, icing).They took avoiding action. They did not fly through the storm. Where the hell does this hundred times disproved notion they penetrated the active storm cell come from?

At Court, to the Judge.It might come as news to some that recorders are fitted to help advance aviation safety and are not intended to be used in connection with civil trials. Even using them in criminal cases is not something aviation authorities look favourably upon.

The key detail is that they had no experience or training in high-altitude manual handling.
It's not a key detail but infrared herring. Issue is not handling but having no idea of the aeroplane's energy state. CM2 stalled aeroplane pretty deftly.

But wasn't Bonin flying with his feet flat on the floor?Recommend reading "Use of rudder on transport category aircraft". It's applicable to almost anything, "applicable only to Boeings" is just a legal boilerplate.

You do a pretty good job, but sometimes you draw some strange conclusions----and I attribute that to lack of hands on experience.If I'were to subscribe to the line of thought connecting his postings quality to experience, I would be forced to admit that experience is quite a hindrance in understanding the AF447.

the company that employed the pilots felt that A330 does not require knowledge of manual flight at high altitude
They were quite correct in that respect, too. No aeroplane requires knowledge of manual flight at high altitude.

this is a potential catastrophe in the waiting ..If the real world conformed to your notions, yes. Fortunately it doesn't care a bit about anyone's ideas how it ought to be. Aeroplane flying high has all the inertia, more speed and a lot less stability & damping compared to the same plane flying lower but it takes a flight of fancy to conclude just from AF447 catastrophe that high manual flight is roughly analog to tight-wire act. Unwholesome experience of TAM crew, as described in 1.16.2 refers.

As if Pitch and AoA are unknown in aeronautics? If I supposed for a second this thread is indicative of the state of the aeronautics, I would have to wholeheartedly agree with you. Luckily, it isn't so.

Correct, but no pilot would accept to remain steady 3 or 400 ft below in RVSM airspace Are you perchance suggesting it wasn't good enough for them so they went for whole 2000 ft bust?

Some experiment has to be done. No way I would volunteer. Would you?

Why not correcting something that is stupid : auto trimming to the point of stall and further into it - Let a pilot take such deadly initiative, don't do it for him. OMG! F-15, F-16, F-18, Rafale, Typhoon, all of the Airbi post 320 are deathtraps, with ueberintelligent pilots required just for everyday operations!

Perish the thought.

Autotrim is just automatic trim. Any aeroplane, anywhere, anytime is properly flown with reference to attitude. Whether the residual stick force after the required performance is achieved is trimmed out manually or automatically is just a minor detail.

So the system will attempt to achieve 1 gee corrected for pitch attitude. Have I read that wrong?Eh... unlike F-16 which has G-trim, Airbus is made to be flightpath stable, so it will achieve 1G in wings level horizontal flight,not by chasing 1G but rather by trying to keep the flightpath constant. If we don't go into details and try to build theories on them, "Stick free it holds 1G" is good enough approximation. Displacing the stick commands the flightpath change with so-and-so gees, proportional to displacement.

This crew, but especially PF Bonin, was not madly pulling on the stick from the loss of A/P, not at all.
Are you accusing BEA of forging the sidestick traces?

Commanding a pitch attitude with the stick will cause autotrim to maintain the pitch attitude at the point the stick was released to the best of its ability.Not quite... it will maintain flightpath so left with nose-up, it will increase pitch as airspeed decays and alpha goes up. However, it is not as bad as some try to make it seem. Pilot needs to be quite incapacitated to leave the aeroplane wonder on her own.

Airbus and the BEA must have thought so because they replicated AF447 and in the Final Report even drew graphs in comparison with AF447's flight data. Yup, up to the point where flight test data were available. A330 was intentionally stalled during flight testing (and recovered, obviously) but never driven to 40° alpha.

It is neither practically nor philosophically merely just an "iterative example of how technology has changed." It is a far more complex human phenomenon that requires the respect of awareness. Technology changes who we are and if we are blind to that, we are blind to its dangers while lauding its benefits.True, but not very applicable to AF447, which was a case of pilots unable to remember and apply basic flying lessons at 4AM, which might be partly affected by not understanding how thin is the Airbus's technological armour shielding from the elements. Precursor of AF447 was described by Wolfgang Langewiesche almost seventy years ago.

You already know I have no problem with automation and all technological advances just so long as one knows one's craft and can do the job when the bytes and pixels quit That's something you share with about every functional aviation authority in the world.

Understood, yes!, but never respected and that means knowing how to fly and think regardless of technology. I'd rather use phrase "cowed by technology" than "having respect for technology" but basically, I agree.

Now I never went back to manual trim airplanes so can't speak for that direction of a transition. Did and can. I didn't know it was an issue until I read it was supposed to be on this thread.

Gotta tellya, that if the AF447 crew had a gut understanding of the system, we wouldn't all be here talking about it.There were other crews in UAS that had no clue what was happening and had no understanding of the system. They sat puzzled and not doing anything. So survived.

Granted a 5deg pitch up at FL350 won't lead to stalling the airplane, but why destabilize the airplane in the first place?Have a look at the pitch; it's not consistent with CM2 doing low level UAS drill at high level, but rather as if he were trying to run away at all costs from something he believed was coming from below to get him.

Wouldn't their Attitude Indicator showing a lot of blue sky given them a clue?They absorbed roll info all right but just couldn't connect the blue on AH and rapidly winding altimeter with idea they will eventually run out of speed and stall.

Lyman

6th Mar 2013, 13:51

It might come as news to some that recorders are fitted to help advance aviation safety and are not intended to be used in connection with civil trials. Even using them in criminal cases is not something aviation authorities look favourably upon.

Noted....

However. "Intended" is the backstop for the righteous. Pragmatically, data is data, and is available to whomever can acquire it.

You are a pilot. You by definition deal in reality, not moral judgment.

Therefore....

Quote:
Originally Posted by Lyman
This crew, but especially PF Bonin, was not madly pulling on the stick from the loss of A/P, not at all.

I direct your attention to the part of the data that is important, to me, that is the beginning, not the end.

This accident happened in twenty seconds, not four minutes. That is my opinion, and always has been.

Are you accusing BEA of forging the sidestick traces?

That is not necessary. At the loss of Autopilot, with cricket and MASTER CAUTION, the aircraft was showing a loss of 370 feet in altitude, and a NOSE DOWN attitude, accompanied by eight degrees of roll, to the right.

PJ2 has posted, initially, "do nothing", which he has amended to mean, don't be precipitous, or ham handed, to which virtually all transport pilots agree.

Pilot flying input NU and RL, as he should. His inputs to me reflected a residual memory of flying in NORMAL LAW, where his inputs would have been modulated.

Big mistake, and perhaps one that caused the crash, at least partially. The next ten seconds show an acclimation to a new and degraded LAW, and an eventual settling of Roll. The PITCH axis remained in a mode that modulated his inputs, and this may have subconsciously affected his muscle memory, in that he was not sufficiently focused on PITCH.

Ninety nine per cent of the posts in this and the other threads focus on the STALL, or the CLIMB, or the CAPTAIN.

It has been established that no one knows what caused the CLIMB, except to hone in on, Pilot Error.

That is fine by me. You?

Lonewolf_50

6th Mar 2013, 13:58

Howdy, Clanedstino, as usual your comments spice up our discussion. :ok:

A few points:
... have a look at the CM2 stick trace! That's made by a guy who believed he would die if he just lets go of the stick! Such accidents are with us ever since the aeroplanes were first stalled! On that we are in violent agreement, but the context of my comment to jcjeant was about the passengers' fear and anxiety being presented in the courtroom as a complaint. Given that they died as a result of the crash, their 'fear and anxiety' seems nearly irrelevant to me ... in that little side bar.
True, but not very applicable to AF447, which was a case of pilots unable to remember and apply basic flying lessons at 4AM, which might be partly affected by not understanding how thin is the Airbus's technological armour shielding from the elements.
CVR time tags indicate about 2:10 AM to about 2:14 AM as "when" this happened. ;)
Have a look at the pitch; it's not consistent with CM2 doing low level UAS drill at high level, but rather as if he were trying to run away at all costs from something he believed was coming from below to get him. His ex wife perhaps? Legend has it that harpies know how to fly:}. Your post made me chuckle. :ok:
Mac the Knife
Wouldn't their Attitude Indicator showing a lot of blue sky given them a clue?
Clandestino
They absorbed roll info all right but just couldn't connect the blue
on AH and rapidly winding altimeter with idea they will eventually run out of speed and stall.
At the risk of being pedantic, by "winding" do you mean increasing or decreasing? I presume the former. If you meant the latter, it would indicate "already stalled" to the discerning pilot.

EDIT:
As to "what they were probably thinking" I will mildly disagree with you.
a. Probably nothing at all.
b. Control inputs and cockpit audio bear no trace of anything that suggest the presence of rationality.
c. They were panic stricken.

a. Probably thinking "why's it doing that?" or "Why isn't it doing what I expect it to do?" (even though what was expected might not have been aligned with how the aircraft systems work) and then "What's it doing now?" and later on, at least from the right hand seat "WTF is going on here?" There may also have been some background thought on "Why is that stall warning going off?"

b. They indicate a crew behind the aircraft. There were reasons for some of what they did, hence a rational thought process, but those reasons seem to have been based on faulty diagnosis of their problem, faulty recall of procedures, and faulty flying skills, and faulty CRM technique.

c. In the last minute, maybe so, but in the first three, confused more than panic stricken ... unless there's more to my guess about the pursuing harpy than my wisearse comment warrants! :}

Lyman

6th Mar 2013, 14:25

Are you accusing BEA of forging the sidestick traces?

But if I wanted to, I would......

A330 has shown some eccentricities in Flight Control, to wit, uncommanded climb.....

Suppose Air France flight 447 had been victim of these "eccentricities"?

The "CLIMB" was instead a desperate attempt by Bonin to FORCE the nose DOWN, not hold it up?

If 447 had been lost to Airbus, not BONIN, what then? Can you imagine?

"AIRBUS kills 228 over the ATLANTIC" Boy Howdy. Until the boxes were found, who could say? Afterwards, and in the possession of an agency that had been accused of criminal conduct to protect the airframer prior, who could say "The pilot performed as expected in the CLIMB emergency, and all the way to the OCEAN"..."He tried the entire while to drop the nose, by pushing the Stick forward".

Without ACCESS? In the possession of those who refuse to release all the DATA?

It would seem a simple task, disclose.

What would I do? Right Wrong or indifferent, I would do the same. Keep the "DATA" secret, and a passive non emotive expression....

Pragmatic.
After ALL, they're all dead.....

PJ2

6th Mar 2013, 15:33

3holelover;
Have I understood the display correctly? Yessir, that's what the display says and you've understood it correctly.

It has never been my sense that an AoA indication somewhere on the forward panel or screen real estate would have made a difference to the AF447 outcome. As with the FPV, an AoA indication is part of the kit only when its information is understood within its context of high-altitude, high-speed swept-wing flight.

Lonewolf_50;
In Re the original quote, Quote:
Originally Posted by Mac the Knife Wouldn't their Attitude Indicator showing a lot of blue sky given them a clue?They absorbed roll info all right but just couldn't connect the blue on AH and rapidly winding altimeter with idea they will eventually run out of speed and stall.I took the use of "winding" to mean the climb, (vice the term, "unwinding" to mean a descent).

The altitude and rate of climb would have been visible on both PFDs.

Clandestino;
Quote:
Originally Posted by PJ2
Granted a 5deg pitch up at FL350 won't lead to stalling the airplane, but why destabilize the airplane in the first place?Have a look at the pitch; it's not consistent with CM2 doing low level UAS drill at high level, but rather as if he were trying to run away at all costs from something he believed was coming from below to get him. Yes, it's not consistent certainly but merely "mostly in the direction of..." which is inconclusive as to reason and so open only to theory.

The data clearly indicates that in percentage time, the SS was in the NU position most of the time and the left and right elevators were entirely in the NU position throughout the descent:

http://www.smugmug.com/photos/i-GRhjsb6/0/X2/i-GRhjsb6-X2.jpg

PJ2

DozyWannabe

6th Mar 2013, 16:51

It's not a key detail but infrared herring. Issue is not handling but having no idea of the aeroplane's energy state. CM2 stalled aeroplane pretty deftly.

Not sure I agree with the first sentence - if HA manual handling was taught as part of basic conversion training, then there would have been a reinforced mnemonic inside the F/Os' heads that pulling up to that extent in the cruise is a very bad idea. As are large control inputs in general.

Not quite... it will maintain flightpath so left with nose-up, it will increase pitch as airspeed decays and alpha goes up. However, it is not as bad as some try to make it seem. Pilot needs to be quite incapacitated to leave the aeroplane wonder on her own.

Agreed - the point I was making is that with this system, the aircraft will do it's best to go exactly where you point it until either it can no longer comply, or until you point it somewhere else. This consequently means that while handling the aircraft is a simpler process, levelling off must be a distinct and conscious act - but that's not really different than for any other type.

But if I wanted to, I would......

Then firstly, do you not think it slightly presumptuous to infer that an accident investigation service who are compelled to abide by strict standards would do the same? And secondly, with due respect, I'm damned glad you're not an accident investigator.

Hopefully this thread will shortly return to rest, 'cos there's nothing new being discussed here.

Turbine D

6th Mar 2013, 18:10

Lyman,
"He tried the entire while to drop the nose, by pushing the Stick forward".
After lurking and reading the recent posts on this thread, it's time for a reality check. From the BEA Final Report:
Pg.173: Following the autopilot disconnection, the PF very quickly applied nose-up side stick inputs. The PF's inputs may be classified as abrupt and excessive. The excessive amplitude of these inputs made them unsuitable and incompatible with recommended airplane handling practices for high altitude flight.
The chart on Pg.96 showing PF's Side Stick Pitch Position confirms this.
Pg.183: In the first minute after the disconnection of the autopilot, the airplane exited its flight envelope. Neither of the two crew members had the clarity of thought necessary to take the corrective actions. However, every passing second required a more purposeful corrective piloting input.
After autopilot disconnection the nose-up inputs produced a load factor of up to 1.6 g, that is to say 1.4 g if the turbulence component is excluded. Maintaining a high pitch attitude first resulted, when the airplane had sufficient speed, in a fast climb speed (up to 7,000 ft/min) and then a rapid increase in angle of attack. At high altitude, such climb speed can only be achieved by converting kinetic energy to potential energy, that is to say at the expense of rapid decrease in flight path speed.
In addition, the thrust value of 84% N1 was lower than the thrust necessary for level flight (95% N1) due to the reduced mach ordered a few seconds before autopilot disconnection, then changed to "Thrust Lock" mode at 2 h 10 min10. The thrust was readjusted towards CLIMB at 2 h 10 min 23 even though the airplane was already climbing rapidly with a vertical speed of 6,000 ft/min.
These factors induced a rapid reduction in the kinetic energy and brought the airplane above its lift ceiling, at a Mach level at which it was then flying. This rapid exit from the flight envelope was not understood and thus not anticipated by the pilots.
One more time, It wasn't the airplane that caused this...

gums

6th Mar 2013, 18:11

Before returning to the peanut gallery amongst this august group of heavy pilots, I shall once again challenge Cland.......

From A330 FCOM:

http://sluf.org/misc_pages/buspitch.JPG

So the jet "appears" to be a pitch attitude command, and the turn implementation appears to also allow for the gee involved to maintain both the established pitch AND roll. We all know that 60 degrees of bank requires 2 gees, and so forth, huh?

Eh... unlike F-16 which has G-trim, Airbus is made to be flightpath stable, so it will achieve 1G in wings level horizontal flight, not by chasing 1G but rather by trying to keep the flightpath constant. If we don't go into details and try to build theories on them, "Stick free it holds 1G" is good enough approximation. Displacing the stick commands the flightpath change with so-and-so gees, proportional to displacementMy point is that the sucker is a one gee jet, and the autotrim will allow the pilot to relax the stick to maintain an attitude. Our pure gee command ( gear up) resulted in us being neutral WRT speed stability, so we had to use power to maintain a constant speed. Gear down we had an AoA bias to make the jet "feel" like a "normal" jet, similar to the 'bus "flare mode"

And note the phrase in FCOM "With the side stick neutral, the system maintains one gee in pitch corrected for pitch attitude" How one can assert the jet is a pitch attitude control law still bothers me. It may appear to be an "attitude control law", but it ain't. And that's why I said the actions of the THS and such could have an "insidious" effect that some may not appreciate.

Further, my understanding of aero is that a straight mechanical system that we had long ago, and in some jets to this day, you trim for AoA, not gee, not attitude, not speed. I think most of us learned in planes like that, ya think? Ask Mach or Smilin' Ed or any Navy type, and even some of we Air Force pukes. And so...

Autotrim is just automatic trim. Any aeroplane, anywhere, anytime is properly flown with reference to attitude. Whether the residual stick force after the required performance is achieved is trimmed out manually or automatically is just a minor detail.True, we normally fly to achieve an attitude and simply keep the AoA below the stall angle. Trim to reduce the stick force requirement and so forth. However, many of us were taught to trim for a speed when climbing or descending, and especially for final approach. Not necessarily an attitude. And that's AoA, which works with thrust and the induced drag to get the "speed". Then your power controls the climb angle/climb rate, or the other way.

I do not intend to conduct the pre-flight instruction for my newbie student for most here. I just want to point out the way the 'bus is designed from looking at the manuals and such some of you presented to me.

DozyWannabe

6th Mar 2013, 18:58

And note the phrase in FCOM "With the side stick neutral, the system maintains one gee in pitch corrected for pitch attitude" How one can assert the jet is a pitch attitude control law still bothers me.

He's not - he's saying it's a stable flightpath control (of which pitch attitude is a single factor).

I think most of us learned in planes like that, ya think?

And as has been pointed out, behaving like a scaled-up trainer was not part of the design specification for this system, which is why the actual behaviour and the differences from a "traditional" setup are front-and-centre in conversion training.

HazelNuts39

6th Mar 2013, 19:10

Accelerations are usually measured in the body-axis system: ax along the longitudinal axis, ay perpendicular to the plane of symmetry, and az perpendicular to ax and ay.

"1 G in pitch corrected for pitch attitude" probably means 1G along the earth vertical, i.e. constant vertical speed.

Lonewolf_50

6th Mar 2013, 19:10

Dozy, Power + Attitude = performance when flying.
(For a given configuration, be it clean, flaps at x degrees, gear down, whatever ....)

To trim for G or flight path, rather than for attitude, is to add complexity to that simple performance formula. There may be good design reasons for that to include passenger comfort, optimal cruise fuel consumption, or a dozen other factors.

Once the conversion course is over, who is flying, and how often? Considering recency and frequency of training and prifociency in flying: who is flying and how, when they are flying and particularly when they are hand flying?

(regarding AF 447 and a few other UAS events, without airspeed indications, you don't have a critical performance instrument, but you do have available in this case both pitch and power information, and you have both altimeter and VSI to get a sense of "level" or '1 G' flight, or something other than that).

Last of all, if like most pilots you are initially taught the above forumula, and imbed that relationship first, how many reps of a different conceptual approach do you need in order to fly "G" or "flight path" rather than pitch using your hands and feet, and internalize that? Varies with each pilot, I suspect.

I'd be interested to hear from those who do pilot training and conversion comment on the above. When pilots actually fly the Magic Bus, are the pilots flying pitch and power?

Some apparently do. (based on various inputs from actual pilots in 3+ years of this topic)

Are they wrong to do so, since the plane as designed isn't meant (under the Normal condition) to fly attitude but rather flight path? (It was painful for me to type that, but that is where this sub genre of discussion of flight modes and laws has taken me).

HazelNuts: zero vertical speed translates to "0" on the VSI when flying, right? ;)

HazelNuts39

6th Mar 2013, 19:36

Lonewolf 50

right!

DozyWannabe

6th Mar 2013, 19:38

Dozy, Power + Attitude = performance when flying.
(For a given configuration, be it clean, flaps at x degrees, gear down, whatever ....)

Understood (and I have a similar equation written down from my Air Cadet days!).

To trim for G or flight path, rather than for attitude, is to add complexity to that simple performance formula.

Sure - and as HN39 suggests, I think the flightpath in the y axis amounts to "this pitch, at this V/S at this airspeed". The calculations may be more complex, but the intent was to make things transparent to the pilot.

Given that Airbus supplied pitch/power data to pilots from the get-go I think that aspect works in much the same way as it does on other types as long as you stay within the envelope. Even if there were some variation I have a strong suspicion that it would be barely noticeable.

HazelNuts39

6th Mar 2013, 20:18

Flying the pitch and power given in the table will keep the airplane within the envelope. Small power adjustments may be necessary to maintain a given altitude.

Lonewolf_50

6th Mar 2013, 20:30

Given that Airbus supplied pitch/power data to pilots from the get-go I think
They doubtless provided weight and balance tables as well. :rolleyes: That isn't as important is the issue of "you tend to play the way you practice."

What is practiced?

PJ reproduced an A320 pitch and power table from the 90's. If you practice using that, or resorting to it under conditions X, Y, or Z, then when you are missing that critical performance instrument, airspeed, you call that up and proceed.

If that's how you train.

jcjeant

6th Mar 2013, 20:37

Hi,

Lonewolf_50
Given that they died as a result of the crash, their 'fear and anxiety' seems nearly irrelevant to meMaybe not important or irrelevant for you ...
But it is very important for the lawyers of the victims families and judges who have to fix and evaluate the compensation to be paid to the parties concerned
Because it is precisely people died that compensation should be paid (in accordance with the laws in force governing such allowances)
And you should know that if in addition to die .. victims have suffered moral damage before death (fear of death .. anxiety .. etc .. ) .. the allowance must be increased
Ask any lawyer about it .. and he will tell you the importance of these details (irrelevant for you) for the assessment of compensation

DozyWannabe

6th Mar 2013, 20:49

What is practiced?

PJ reproduced an A320 pitch and power table from the 90's.

Well, here's a link to the procedure documents in effect at the time, which PJ2 reckoned was more confusing - it's certainly more complex and involved :

http://www.bea.aero/docspa/2009/f-cp090601.en/pdf/annexe.06.en.pdf

I guess it depends what you mean by "practiced" - as far as I can tell the intent was to follow the procedures outlined in the above document in the event of unreliable airspeed, but as to whether or how often these procedures were drilled, I can't say.

Lonewolf_50

6th Mar 2013, 21:46

I guess it depends what you mean by "practiced" - as far as I can tell the intent was to follow the procedures outlined in the above document in the event of unreliable airspeed, but as to whether or how often these procedures were drilled, I can't say.
I can't say either, which is why I posted:
I'd be interested to hear from those who do pilot training and conversion comment on the above. When pilots actually fly the Magic Bus, are the pilots flying pitch and power?

Some apparently do. (based on various inputs from actual pilots in 3+ years of this topic)
Won't make any comments on KISS principle, and the link you provided, since we are dealing with fly by wire aircraft.

Lonewolf_50

6th Mar 2013, 21:47

Because it is precisely people died that compensation should be paid (in accordance with the laws in force governing such allowances) And you
should know that if in addition to die .. victims have suffered moral damage
before death (fear of death .. anxiety .. etc .. ) .. the allowance must be
increased
Please pardon me while I puke.
:yuk:
Thanks.

bubbers44

6th Mar 2013, 22:09

Some pilots here don't agree with my thinking their 11 degree pitch attitude which is impossible without a stall not causing this whole event. My method of flying would have been to hold about 2 degrees nose attitude up and hold altitude as would have all of my pilot friends. Adjust power as necessary to maintain altitude and everything would have been fine. But if you follow the magenta line that probably isn't possible using the FD as your pitch mode. Why do people hire these guys? It never happened in my era.

DozyWannabe

6th Mar 2013, 22:12

Won't make any comments on KISS principle, and the link you provided, since we are dealing with fly by wire aircraft.

Well, the way it's set up is such that if the aircraft was relatively stable prior to UAS-induced AP disconnect, then it will remain relatively stable without intervention for longer than a more conventional type, because even without AP, the flight control system is still managing trim to keep the aircraft pointing where it was last pointed and the thrust control is locked at the last setting. Strictly speaking, this then gives the crew time to get the books out if necessary and apply the correct procedures. From a piloting perspective that's got to be as simple as it gets, no?

Lyman

6th Mar 2013, 22:18

TurbineD

Quote:
Pg.173: Following the autopilot disconnection, the PF very quickly applied nose-up side stick inputs. The PF's inputs may be classified as abrupt and excessive. The excessive amplitude of these inputs made them unsuitable and incompatible with recommended airplane handling practices for high altitude flight.

Where does it say that the pilot's inputs were not inconsistent with flight in Normal Law? Clearly, the pilot, by evidence of the SS traces, is laboring under the illusion that his stick stirring is not going to produce a problem. Has he missed something? Debatable...

The prose in the report does not jive with its own conclusion, that the SS actions of the pilot resulted in unsuitable results. They did in hindsight, but as gums tells us, this manner of control response is more insidious than many will consider.

Failing that, the results of the Pitch commands can just as easily be laid off on inattention to horizon, which is just as culpable...Any unsuitable results that are caused by a collection of miscues are not the result of just one. Do you not see the prejudice inherent in this text, this report?

Do you not recall the endless discussions regarding the pilots initial Nose Up commands interspersed with Nose Down? The discussion re: a lack of initial response of the aircraft? Sluggishness? Where is that? Only the "emphatic" and "inappropriate" NU......

As to:

Quote:
"He tried the entire while to drop the nose, by pushing the Stick forward".

That is in quotations as it is intended to be a consideration, a possibility offered to frame a possible accusation of malfeasance.

The final decisions made as to the manner and content of this report is up to......Politicians. I take it therefore, with some copious quantity of NaCl....

Bill

DozyWannabe

6th Mar 2013, 22:32

Where does it say that the pilot's inputs were not inconsistent with flight in Normal Law? Clearly, the pilot, by evidence of the SS traces, is laboring under the illusion that his stick stirring is not going to produce a problem.

TD's post had no mention of flight control law, and in pitch the aircraft's response is the same in Alt2B as it is in Normal.

"Clearly" to whom? Your supposition is based on the idea that the inputs were the result of a rational thought process, and unless your skillset includes clairvoyancy - this is something that neither yourself nor any of us can know.

That is in quotations as it is intended to be a consideration, a possibility offered to frame a possible accusation of malfeasance.

Except it is a fantasy. The traces are positive proof that the PF's inputs were overwhelmingly NU in terms of both degree and time.

Finally, the BEA's staff are not politicians, they are civil servants - just like their counterparts in the NTSB and AAIB. If you do not understand the difference, then I'm a little worried.

Seriously, let this one lie and focus on the B787 issues Bill - I've actually been enjoying some of your input there!

Lyman

6th Mar 2013, 22:49

The chronic consistency of Nose UP? Very bad. The "stirring"? Not so much.

Hence my reference to the Horizon. The report condemns the movements, when it was the overall additive result that was the problem.

The results of his manipulation, the excess persistent PITCH was the problem, yet the report "abrupt and excessive" misleads, had he been abrupt and excessive Nose Down, they may have survived.

If you cannot see the nuance, the prejudice, say so. I believe it is there.

Nothing wrong with abrupt, nor excessive, if countered. No harm to the control surfaces, no complaints about the ride, only the attempt to portray the Pilot as clumsy.

TurbineD

What of the Report's mention of "machine" shortcomings, that may have exacerbated the crash's entry? No AoA, Stick invisibility, etc. ?

"It wasn't the airplane that caused this..."

PJ2

6th Mar 2013, 22:51

Lonewolf_50;
1. Once the conversion course is over, who is flying, and how often? Considering recency and frequency of training and prifociency in flying: who is flying and how, when they are flying and particularly when they are hand flying?

2. (regarding AF 447 and a few other UAS events, without airspeed indications, you don't have a critical performance instrument, but you do have available in this case both pitch and power information, and you have both altimeter and VSI to get a sense of "level" or '1 G' flight, or something other than that).

3. Last of all, if like most pilots you are initially taught the above forumula, and imbed that relationship first, how many reps of a different conceptual approach do you need in order to fly "G" or "flight path" rather than pitch using your hands and feet, and internalize that? Varies with each pilot, I suspect.

4. I'd be interested to hear from those who do pilot training and conversion comment on the above. When pilots actually fly the Magic Bus, are the pilots flying pitch and power? I think these are good questions / discussions on important & relevant matters which still have lessons to teach even as AF447 has been thoroughly dissected, (same thread, for context - slight shift in focus, etc). This is about airmanship, aerodynamics, systems knowledge and, most importantly, effort, a.k.a. "keeness", in terms of what one puts into learning one's craft and profession. So this applies currently and widely.

I've numbered your paragraphs for easy reference. The following is one pilot's experience / interpretation and therefore isn't definitive. I know you know this!

1. (Note: Conversion or Transition course footprints for new types, say A320 to A330, B737 to B767 or A320 to B777 etc, are usually 56 days give or take. Line Indoctrination flying, (regular routes with passengers with a line-indoc captain in either seat depending upon if the candidate is F/O or Captain) is usually included in this footprint but factors can extend this time although it's rarely less.

With that in mind, once the transition course is completed pilots flying long-haul overseas routes in western-built B777/B747/B767/B757/A340/A330/MD11, whether new on the airplane or have been on a long time, are generally working three trips per month, sometimes with a domestic filler. Long haul monthly hour limits vary between 80 and 95hrs with slight variations either way. That usually isn't hard (stick) time as there are 'flight-time guarantees' sometimes built into the schedule. Actual, logged stick time for most of these pilots (domestic & international) is usually about 600 - 1000hrs per year depending upon the nature of the operation.

The takeoff and the late approach / landing phases are almost always hand-flown. These two phases are the only portions of the flight which are hand-flown. It is illegal to hand-fly in RVSM airspace, complicated SIDS and STARS require precise navigation and altitude/speed control and generally the crew is tired at the end and the engagement of the autoflight system is of great value. So the hand-flying portion of most all flights lasts between 8 and 15 minutes, obviously with outliers where pilots choose (and are permitted) to hand-fly the entire departure and climb to cruise altitude, and the descent, approach and landing at destination.

The breakdown is roughly three minutes for the takeoff and initial departure. Takeoff lasts less than 1 minute, initial climb and establishing enroute about six to eight minutes but the autoflight is almost always engaged right after takeoff, mainly for reasons of navigation/speed/altitude precision and crew workload. There is nothing preventing hand-flying of the departure but everyone needs to be right on top of things to do so. The workload is higher but for a good crew that is not a problem.

The descent and approach phases are almost always flown on autoflight with disconnection around 400ft above airport elevation. Autolands are rarely carried out except when required. Autoland works extremely well. Hand-flying the late approach, (FL100 or below) is rare but is usually permissable and a lot of fun as well as very good practice but the same constraints apply so if one disconnects it's later in the approach phase...8 minutes is a reasonable estimate.

This phase (FL100 / arrival), usually lasts about 12 to 17 minutes depending upon the terminal.

From the FAF / OM, (Final approach fix or Outer Marker, (for others, about 4nm to the runway)) to touchdown is usually just over 2 minutes. From 400ft to t/d is about 40 to 50 seconds.

Based on these numbers, long-haul pilots are getting about 3 minutes of hand-flying on takeoff and about 50" of hand-flying on approach. If crews fly three long-haul trips and one domestic that's usually eight legs, perhaps ten and at the most a dozen legs per month. The flying is usually shared between Captain and F/O. At some carriers the third or fourth crew members are regular F/Os or Captains while other carriers use what are known as "Relief Pilots - RPs" who occupy the front seats only in cruise and are not permitted to sit up front below cruise altitudes. This has more to do with cost than anything else but the point is, the tiny time available for hand-flying is shared between at least two pilots, possibly three.

Per trip the available hand-flying time for the crew is approximately:

Takeoff and initial departure: Max 6 minutes, min 3 minutes;
Approach and landing: Max 8 minutes, min 1 minute

Per month the time is about Max 56 minutes, minimum 16 minutes.

For 11 months approximately, (can be less, depending...), the available hand-flying time is about 10hrs 15minutes max or about 3hrs minimum.

For the discussion let us say it is shared between just the two pilots up front.

Divided between the two pilots, hand-flying time for a long-haul pilot is just over 5hrs per year max and about an hour and a half minimum. The rest is flown on autoflight.

2. My sense of "level flight" was as you have said, the IVSI and Altimeter, but definitely not 'g'. Any "g" felt always signals a transition and one always waited for stability while watching/reading the instruments, almost always for verification of expectations and not to see what the airplane was doing.

3. I don't think that for a pilot the pitch / power and performance equation governs how one flies. I think it just has to be experienced and then the intuition comes quickly in ab initio work as well as transition work. I think this kind of knowledge explains afterwards what happens when one flies and so I wouldn't know how to teach it. I think one can only teach (or cause to learn) what it looks like but one can't teach what it feels like. I think that that kind of aeronautical knowledge-building goes right back to ab-initio work when one begins to learn how to fly. Those are the connections being made when one is being taught attitudes, slow flight, stalls and forced landings, (the glide). It is very difficult to teach that stuff (pitch & power) on transport airplanes first because the same power settings can result in different speeds, (Davies) but mainly because the changes are too tiny and the outcomes too large to appreciate the real connection. That's what's meant for example, by "tiny changes in pitch result in massive climb or descent rates". You don't see that in a little airplane, you just see the speed drop off if you pitch up and don't add power or the nose drop if you reduce power and it becomes (or should!) an "aha" moment. It works the same in heavy transports but at much different scales and effects which make it very difficult to demonstrate, (and one shouldn't be demonstrating such work at that stage anyway!).

4. My experience from the DC9 through to the A340/A330 was to fly pitch and power, and both thrust levels and trim complemented this intuitive learning, aided by some very patient captains and as well as by some who weren't patient at all. The A320/A330 were flown exactly the same way but the feedback loops were different but the sound of the air going by the airplane, pitch attitude vs power setting and one's feeling in the seat were the same. Clandestino has commented that the transition back to manually-operated trim (from the AB autotrim) was a non-event and I would agree that it would be easy to pick up say on a B777 or B767, (it might be more challenging if one had never flown non-AB aircraft).

The problems to overcome while transitioning to an Airbus are twofold: The fear of disconnecting, and the fear that it will do something you don't want. Both fears are fought by disconnecting everything regularly and hand-flying where one's company's policy permits. It takes work, study and patience to learn the airplane and it's not as straightforward as the B767 or B777. One does not put the books on a shelf, sit back and wait for someone else to teach them every six months in the sim (or in the office). But I am increasingly hearing of such things as well as hearing that not many pilots disconnect anymore. I think that's a problem.

On learning, on pitch/power and bringing keenness and enthusiasm to the profession for life-long learning, others will hopefully have different views to contribute.

PJ2

DozyWannabe

6th Mar 2013, 23:23

The results of his manipulation, the excess persistent PITCH was the problem, yet the report "abrupt and excessive" misleads, had he been abrupt and excessive Nose Down, they may have survived.

No - the failure to first monitor the aircraft's behaviour *prior* to making control inputs was the problem. The correct course of action was to wait and be prepared to take the controls - but first *monitor* the change in the situation, note that airspeed was no longer available and call for the UAS checklist.

Until that was done there was absolutely no reason to start manipulating the stick.

Clandestino

6th Mar 2013, 23:24

CVR time tags indicate about 2:10 AM to about 2:14 AM as "when" this happened.Interestingly, unlike NTSB's, BEA report doesn't mention crew's previous activity. IIRC, it was mentioned that captain and more senior F/O arrived from Paris on the previous day so their body clock would be synchronized to CET, which was UTC+2 at the time of the accident. If I am not mistaken, more junior F/O joined the crew in Rio, after vacationing there and his wife was in the cabin so his body clock would be nearer to midnight.

I presume the former. Correct, I was referring to pre-stall maneuvering .

Probably thinking "why's it doing that?" or "Why isn't it doing what I expect it to do?" Agreed.

There were reasons for some of what they did, hence a rational thought process, but those reasons seem to have been based on faulty diagnosis of their problem, faulty recall of procedures, and faulty flying skills, and faulty CRM technique. There were reasons but that they were not verbalized indicate total breakdown in the cockpit. Multi-crew pilots don't think aloud and make callouts just for CVR's sake, it's the way of keeping the other guy/gal in the loop. CM2 quickly realized speed indication is faulty but made no appropriate response which would be in descending order of appropriateness: a) just keep the attitude and power where they were b) apply climb thrust and 5° ANU until pitch/power table is available c) do nothing and just wait for the aeroplane to fly herself out of the icing area d) alternatively pull inanely then push when stall warning goes off. Crews performing c) and d) not just survived but didn't damage aeroplane or hurt anyone, despite their response being waaay sub-optimal. CM1 did not acknowledge CM2 concerns or checked them for himself but rather added to cunfusion by suggesting "watch your speed".

In the last minute, maybe so, but in the first three, confused more than panic stricken ... We are probably talking semantics here but I can agree that total breakdown of situational awareness, inability to understand the aeroplane's performance and lethally paradoxical reaction to stall warning are indicative of severe confusion.

Yes, it's not consistent certainly but merely "mostly in the direction of..." ...and pitch happily exceeding targets even for "below acceleration altitude" case with CM2 strangely quiet and at the best totally vague on what he believes is going on.

Not sure I agree with the first sentence - if HA manual handling was taught as part of basic conversion training, then there would have been a reinforced mnemonic inside the F/Os' heads that pulling up to that extent in the cruise is a very bad idea. As are large control inputs in general.I see your point and I can agree with it - folks who forgot high altitude performance part of their ATPL theory could be reminded of it as preparation of HA manual handling. As for large control inputs at HA, they are not problem per se, as long as they are not sustained in one direction or they cause divergent oscillation, both of which may end up in irrecoverable attitude.

Case of TAM flight on 12 November 2003

This case, which happened to an A330-200, was not one of the thirteen events studied
above because no crew report was available. However, in the light of the data from
flight AF 447, it seems useful to mention it. In fact, following icing of at least two
Pitot probes at FL360, the crew made some high amplitude flight control inputs (to
the stop), sometimes simultaneously. When the AP disengaged, both pilots made
pitch-up inputs (one went to the stop) that resulted in an increase in pitch of 8°. On
several occasions, the stall warning was triggered due to the nose-up inputs, and the
crew reacted with strong pitch-down inputs. During the 4 minutes that the sequence
lasted, the load factor varied between 1.96 g and -0.26 g, the pitch attitude reached
13° nose-up and the angle of attack reached 10°. Altitude variations, however, were
less than 600 ft.Hell of a roller-coaster ride, eh? Result was: no injuries, no damage and in a spectacular display of ignorant coolness - no report.

So the jet "appears" to be a pitch attitude command, and the turn implementation appears to also allow for the gee involved to maintain both the established pitch AND roll. We all know that 60 degrees of bank requires 2 gees, and so forth, huh?I think it is at least third time I'm discussing this sentence, so I'm saying again: "system maintains 1G" is description of the end result, not of the underlying operating principle.

What kind of algorithm would system that actively chases 1G use to cope with bank? Pitch? Turbulence? Maintaining the inertially derived flightpath elegantly solves all these problems and fits well stable and quite unmaneuverable machine whose raison d'être is to carry passengers from A to B economically and safely and not to shoot down or bomb anyone in the process.

Anyway, pilots absolutely need not to be aware of all the intricacies of the FBW all the time as aeroplane's response is strictly conventional. Pushing the stick moves the nose down, pulling it left rolls the wings left and vice versa. If the aeroplane doesn't respond, you have truly messed up and better quickly figure out what is going on and how to unmess yourself.

How one can assert the jet is a pitch attitude control law still bothers me. It shouldn't. While not strictly true, difference in feel is negligible.

Further, my understanding of aero is that a straight mechanical system that we had long ago, and in some jets to this day, you trim for AoA, not gee, not attitude, not speed. Still true, trim is for AoA but pilot needs not be concerned about it. If thinking that he trims for speed simplifies his job with no adverse consequences, then so be it.

Last of all, if like most pilots you are initially taught the above forumula, and imbed that relationship first, how many reps of a different conceptual approach do you need in order to fly "G" or "flight path" rather than pitch using your hands and feet, and internalize that?None at all. Airbus is still pitch+power=performance aeroplane. You set the nose where you want it to be, apply power you want and check that performance is as expected. You don't trim her or think about gees as you move the stick, you just fly it and boy, does the 320 fly sweetly. I pity the fools who program the FMGS with circuit waypoints and let the AP fly the visual approach.

Are they wrong to do so, since the plane as designed isn't meant (under the Normal condition) to fly attitude but rather flight path?Eh? Not sure I'm following you here. Pilot flies the attitude and FBW makes his job easier by maintaining the flightpath, what you basically get is FBW automatically compensating for turbulence. There is chance for PIO if you are not expecting it but it's easy to get used to.

It never happened in my era. It did. Stony point. (http://aviation-safety.net/database/record.php?id=19741201-1)

DozyWannabe

6th Mar 2013, 23:42

As for large control inputs at HA, they are not problem per se, as long as they are not sustained in one direction or they cause divergent oscillation, both of which may end up in irrecoverable attitude.

Agreed - substitute "large" with "large and sustained" in my original post.

Turbine D

7th Mar 2013, 00:00

TurbineD

What of the Report's mention of "machine" shortcomings, that may have exacerbated the crash's entry? No AoA, Stick invisibility, etc. ?

"It wasn't the airplane that caused this..."
That is because no shortcoming entered into what happened starting with the autopilot disconnect and continuing until the stall. The PNF knew, from the display he was watching, the attitude of the aircraft wasn't correct and told the PF so. So what difference did it make regarding "stick invisibility" in reality? If you think, not being able to discern the attitude of the aircraft (way nose up) from the color display, what would interpretation of a separate AoA instrument add to the mix for this crew? Everything was there to prevent this accident, but they just didn't remember it...

bubbers44

7th Mar 2013, 00:27

Yes, that is what I had done. Why pull up to 11 degrees attitude knowing you are going to stall if you are a real pilot. These guys had no clue what they were doing.

DozyWannabe

7th Mar 2013, 00:56

What's your definition of "real pilot", bubbers?

If you mean pre-FMS/"magenta line", then as Clandestino has pointed out this has happened before to an old-school crew on a NWA B727.

As far as we can tell from the CVR, the PF never really fully appreciated the situation and at least for some of the time had (wrongly) convinced himself that they were in an overspeed situation. On any other day he may not have made that mistake, but on this occasion he did. This implies that his emotions and instinct overruled his rational thought processes, but it does not mean that he was an incompetent pilot.

You can be considered the premier pilot in your airline and still make mistakes - Tenerife proved that.

bubbers44

7th Mar 2013, 06:29

A real pilot doesn't let automation override his basic flying skills. A real pilot can recover from a stall quite easilly without the aid of a FD. A real pilot knows what his aircraft is capable of doing at high altitude and what it is not capable of doing. Real pilots usually don't end up in the newspaper because they did something incredibly stupid. I guess real pilots also remember the days when you knew how to swing a prop to start an aircraft with no battery installed. Maybe I am just getting old but the new brand of pilots flying the magenta line seem to have not learned the basic skills we all grew up with.

jcjeant

7th Mar 2013, 10:24

As far as we can tell from the CVR, the PF never really fully appreciated the situation and at least for some of the time had (wrongly) convinced himself that they were in an overspeed situation. On any other day he may not have made that mistake, but on this occasion he did. This implies that his emotions and instinct overruled his rational thought processes, but it does not mean that he was an incompetent pilot.It is incomplete ... you forget the other two pilots
That is also the date they were having a bad day?
Three have a bad day at the same time and same place
Bonin going viral?
A challenge to the statistics?

Lonewolf_50

7th Mar 2013, 13:31

PJ2: thanks for taking the time on that reply. Very well answered, I am. :ok:

Clandestino: body clock adjustment points noted.

Pilot flies the attitude and FBW makes his job easier by maintaining the flightpath, what you basically get is FBW automatically compensating for
turbulence.
Is this in all laws other than direct?

Lyman

7th Mar 2013, 16:23

Quote:
Pilot flies the attitude and FBW makes his job easier.......

Isn't "flying attitude" the same as flying Angle of Attack?

If so, should AOA be readily available? If not, should one depend on FD?

If FD is selected OFF, (as it would be post UAS), what then? PITCH?

That might be just the wrong cue....

HazelNuts39

7th Mar 2013, 16:58

AoAIsn't "flying attitude" the same as flying Angle of Attack?Pitch attitude equals AoA in level flight. Otherwise it does not.

Flying pitch and power causes the airplane to acquire a stable condition of airspeed, flight path angle and AoA. Flying AoA causes the airplane to enter into an oscillary motion known as a 'phugoid' .

Lyman

7th Mar 2013, 17:09

Yes, thanks. In the case of 447, in an unusual climb, and even before, during the first STALL WARNING, AoA and PITCH were discrepant. STALL functions from the AoA vanes, could the pilot have rejected this warning as false (it was not) for that reason?

A severe updraft, or other unexpected event could disorient a crew at a very inopportune time.....Or set the stage for a mistrust of the STALL system....

For that matter, an inaccurate or even erroneous AoA reading could trigger a protection, the aircraft is not invulnerable, (uncommanded climb).

And thank you for the Phugoid reminder. I have believed from the start that the Pilots were having a time with altitude. Whatever the PF saw, and to a lesser extent the PM, what are the possibilities of a PITCH phugoid, either real, or sensate? Such that a chronic climb derived from incorrect input?

Rhetorical, if you like....

Owain Glyndwr

7th Mar 2013, 18:54

what are the possibilities of a PITCH phugoid, either real, or sensate? Such that a chronic climb derived from incorrect input?Nil. There is no such animal. The phugoid is an oscillation in airspeed and altitude at more or less constant AoA. If the control system maintains a constant flight path then the conditions for a phugoid do not exist.

Lyman

7th Mar 2013, 19:29

The flight path was not constant.

Owain Glyndwr

7th Mar 2013, 19:46

Most people think of aircraft stability as being the behaviour of the machine left to itself, not gyrations produced by random pilot inputs. The fact that the flight path varied has nothing to do with any considerations of phugoid stability.

PJ2

7th Mar 2013, 19:47

For that matter, an inaccurate or even erroneous AoA reading could trigger a protection, the aircraft is not invulnerable, (uncommanded climb).Not here. There are no protections in Alternate & Direct Laws. Neither QF72 nor the THY A340 zoom-climb (http://www.rvs.uni-bielefeld.de/publications/compendium/incidents_and_accidents/ACAS-AAIB-dft_avsafety_pdf_501275.pdf) are related to AF447.

Lyman

7th Mar 2013, 19:54

Owain Glyndwr

Like spelling that name, Welsh?

Busy with Roll, and probably not ruddering, the PF had Yaw, Roll and Pitch excursions whilst trying to sort the original eight degree right wing low.

The Pitch was not reliable, by definition, it and gee were not consistent, nor was Vario or much of anything, right after a veryunexpected event.

I think because so much was made of the Roll Direct problem he had, people forget it was Pitch that did them in.

Forget Phugoid, my bad, call it PIO in combination with Roll PIO.

Thanks. Much obliged

Clandestino

7th Mar 2013, 19:57

Is this in all laws other than direct? Yup. I forgot to mention that it will also adjust pitch to compensate for speed or configuration changes. It looks pretty weird when one just reads descriptions in read from FCOM so I approached type rating course apprehensively but it turned out to be quite easy to adapt to Airbus ways, there 's no need to think "what is the FBW doing now" all the time (or at all). We had a lot of movement both from classic controls to Airbus and vice versa but no one ever had problems learning or unlearning the sidestick.

what are the possibilities of a PITCH phugoid

Anything is possible if you don't know what you're talking about.

EDIT:

Forget Phugoid, my bad, call it PIO in combination with Roll PIO.There was no "O" in pitch.

Lyman

7th Mar 2013, 20:07

Blacks Law of disorder...

"The moment one knows everything, something else appears...."

Justice Black

gums

7th Mar 2013, 22:58

Hey, Lyman!

OG, Nuts, PJ and Cland are onto something.

1) Although phugoid mode exists for normal planes, the FBW systems negate it. They are contantly attempting to maintain an attitude or gee. The bus mixes both.

2) Cland mentioned the turbulence a few posts ago. Right on! At low altitude over the desert, with all the thermals and such, our little jet felt like a 757 or something. The system reacted to the up and down quicker than we could - very smooth ride.

3) Only FBW system I know of that uses AoA for trim is the Viper when the gear is down. The 'bus uses pitch attitude a lot more than we did ( we used it ZERO!!!). Could be the Hornet and Raptor and Lightning and Tiffie have a similar control law with gear down. But I an't find any AoA bias for the 'bus unless the sucker is about to get into a stall.

We may discuss the fine points about the control laws and the implementation, but the cause of the crash was a crew problem. Some misunderstanding about the finer points about the control laws may have added to the confusion, but just that.

And thats what this pioneer in FBW jets has to say.

bubbers44

8th Mar 2013, 01:31

The flight path was not constant because of the 11 degree pull up. If they had held a constant 2 degrees nose up attitude they would have been fine holding altitude with a good altimiter.

bubbers44

8th Mar 2013, 01:41

Both pilots in the cockpit were incompetent in my opinion. The captain came up too late to save the disaster. He was taking his required break. He, in my opinion, would not have let this happen. When he saw what was happening he had never seen this before.

PJ2

8th Mar 2013, 07:02

Lyman, entropy is everywhere... :)

Pali

9th Mar 2013, 04:04

jcjeant

9th Mar 2013, 06:09

When captain entered the flight deck wouldn't be an appropriate action to ask kindly Bonin to leave the seat and take over the controls? Would he save the day? Where he was seated the captain had a a panoramic view of all the instruments
In the CVR .. one answer of the captain is
"I don't know"
I do not think it would change something if the captain had taken the place of Bonin when he arrived in the cockpit
Amazing .. but that day three experimented pilots had a bad day at the same place and the same time
A statistical challenge ?
Not so much
Statistics prove that unfortunately this happens often

henra

9th Mar 2013, 10:13

When captain entered the flight deck wouldn't be an appropriate action to ask kindly Bonin to leave the seat and take over the controls? Would he save the day?

Looking at all the information we have there is no serious indication any one of the three understood their real problem (i.e. being stalled) which would have been the prerequisite for any corrctive action. Therefore, although we will never know for sure, it is pretty safe to assume it wouldn't have made much of a difference at that point.
That said there is a minimal chance that when seeing the feedback (behaviour of aircraft vs input) to control inputs made by himself, or better lack thereof, he might have had a better chance to identify they were in a developped stall.
But being where we are now that is a moot point.

Pali

9th Mar 2013, 12:14

Probably yes, just I wonder if captain would pull the way as FO did. But considering the trimmed stabiliser in the position all the way NU it is questionable if captain would have a chance to figure out what to do.

My question is also aimed at usual practice in such cases when senior officer bypasses a junior in an emergency. I am a consultant partly involved into emergency and safety procedures and senior taking over control is one of the paramount rules in almost every industry. So I was wondering if in aviation there is a similar concept. I remember Sullenberger took over really fast after the Flight 1549 went into trouble although I understand he WAS already seated in captain's position.

jcjeant

9th Mar 2013, 12:27

The senior in the cockpit of the AF447 when AP disconnected was Robert
He had the possibility to tell "my aircraft"
Again dunno if this had made a difference ...

TTex600

9th Mar 2013, 20:01

Sorry, if I interrupt all the pro's here, but there is one question which I wanted to ask for ages:

When captain entered the flight deck wouldn't be an appropriate action to ask kindly Bonin to leave the seat and take over the controls? Would he save the day?

Assuming that he would take over, I think the answer is yes. The pilot flying apparently didn't relinquish the controls to the PNF, I have to assume that he would have done so had the Captain been in the Captains seat and asserted his control.

I will also assume that the Captain would have reverted to basic instrument flight skills once in his seat. Whether or not he had the altitude required to recover is the subject of extensive discussion on previous strings on this topic.

HazelNuts39

9th Mar 2013, 22:07

I will also assume that the Captain would have reverted to basic instrument flight skills once in his seat. Would those skills have resulted in push or in pull?

AlphaZuluRomeo

9th Mar 2013, 23:32

Why would the captain take the RHS ???

bubbers44

10th Mar 2013, 00:08

The captain had no time to deal with the upset. He wouldn't have done what they did but came in too late to help. He was required because of rest requirements for their flight to take a break. The junior guys screwed it all up. The captain would have handled it just fine.

Lyman

10th Mar 2013, 00:45

Now is not the time to be modest, bubbers, you have walked up a steep aisle to the door, it is open, and you stride in. You instantly grok the attitude, ten degrees NU, and you proclaim, "Mon dieu mon petit chou, you have STALLED our cherie"....

You would briskly tapout the LHS, settle in, belt up, and look at the PF's SS. "MERDE", "Have you no sense? Look at vario, ALTI, and Attitude!"

"Controls to left, Follow me through...." As you briskly force the SS forward to the stop, you sense an immediate lessening of the chaotic airstream, and you say, "The Nose Down, the wings must be unloaded..." "Take notes, paduan, this may be the only time you see such heroism."

As the Pitch lowers, speed increases, and the noise changes character, not quiter, but less chaotic, you are re-acquiring streamlines, and losing the rumble of the STALL....

You carefully meter the need for back pressure, as your lift is now sufficient to support the a/c, and level flight can be attained, carefully, not too fast, one STALL per leg is sufficient, Non?

Regaining the correct altitude, you give control back to the FO, slowly, casually, you light a Gauloises, and smell the tobacco as it wafts up your Gallic Nose.

"Call Miriam, Pierre, I would like an espresso, two twists."

Anyone who can master the short final at Tegucigalpa can most definitely recover a STALL at 30,000 feet, Non?

bubbers44

10th Mar 2013, 01:13

That was funny. Comparing a Tegucigalpa Honduras approach to crossing the Atlantic. It is quite amusing but pointless.

Both take experienced pilots, but are not what we want our 200 hr wonders to encounter. They need to build experience, not just pushing buttons, but flying the aircraft. Eventually they may be competent to fly if automation fails. Or maybe not.

Lyman

10th Mar 2013, 22:56

As before, I would like to draw attention to the exchange between Captain DuBois, and Bonin, as regards: "Try Climb"...."But I have held aft stick for some time now."

The general conclusion is that Captain cannot see the Stick, and assumes Bonin has Nose Down, input....

It does not matter what Captain sees, because he suggests CLIMB. But he can see the AI, very nose UP. Why would he suggest CLIMB with a NOSE UP on the dial?

Because he assumes Bonin is pushing NOSEDOWN. If he thought the controls were OK, he would command BONIN to push NOSE DOWN, to lower the NOSE. Are we to believe he has not commanded NOSE DOWN until twenty seconds before impact? And not satisfied himself it is not working?

So, he commands NOSE UP? Neither PILOT is happy with the controls' effects, Captain, because he commands NOSE UP with AI full of blue, (supposedly) and Bonin, because he HAS ALREADY TRIED NOSE DOWN, and it has no effect.

He already attempted NOSE UP, as a solution to non working elevators, "But I have tried (am trying) that".

These are two desperate pilots attempting to figure out INOP or problematic controls.

Think about what they have said, as the CVR explains..... Neither pilot can figure out the Pitch, BUT THEY BOTH KNOW IT IS EXCESSIVELY HIGH.

BONIN has tried both NU AND ND, Captain wants to "TRY NU" ("Try Climbing").
At 10000 fpm descent with the gauge all blue? Don't you believe it. He is satisfied the controls are NOT WORKING.

WHY? TO GET THE NOSE DOWN WITH AN INEFFECTIVE CONTROL and unresponsive A/C....

He is thinking, STUCK elevators, or reversed input.

It is IMPOSSIBLE that these two are on different pages, they both know there is a problem, both have tried conformed, and reverse control positions....

Robert gives up too quickly on the altitude (climb) problem. Or does he? He does not take control, is he satisfied that the controls are INOP? Bonin: "We have no control of the airplane..." He obviously is satisfied the controls are ineffective. ARE THEY? Is Bonin referring to loss of control BEFORE THE CLIMB? Would he not brief the Captain on the earliest onset of problem? THE CLIMB?

Lonewolf_50

11th Mar 2013, 15:11

Lyman, I presume that by "ineffective control" you allude to the fact that after a stall control effectiveness isn't what it is while flying.

From what I have seen of the FDR traces, at those times where the SS was moved forward, the attitude (and elevator command) changed toward more "down" but what does not seem to have happened was s sustained and patient nose down input when it was needed. Rate damping and control responsiveness in big jets has been discussed at some length in various previous threads on this topid.

I am a bit confused at your comment on ineffective controls. The SS traces showed me that Bonin tried to get the nose up, and to keep the nose up, and the nose stayed up.
In that regard, the controls were indeed effective.

I realize there are two related elements to the rate of response of nose position inputs: elevator command and THS trim both being part of the package in smoothly changing pitch attitude, and holding it.

Lyman

11th Mar 2013, 16:18

The upshot is that the Captain would suggest "TRY CLIMBING" while the NOSE was so far up in the air.....

That was after an extended period in a very aggravated STALL. The entire conclusion of BEA depends on this.....That it would somehow seem acceptable to the pilot community that the Captain chose ONE TIME to make a suggestion, as to PITCH, and that one instance after completely rejecting what the instruments were indicating? He then relents, and says nothing more?

He heard the STALL warning upon entering the cockpit, and after. Robert? Bonin? DuBois? All three mum as to Stall, and to the need to drop the nose.

The STALL WARN quits below 60 knots, that was attained briefly, but all the way down there was forward speed in excess of 60.

The preponderance of evidence released supports a ludicrous conclusion. There is much evidence that has not been released.

I have made my call.

:ok:

CONF iture

11th Mar 2013, 18:19

When captain entered the flight deck wouldn't be an appropriate action to ask kindly Bonin to leave the seat and take over the controls? Would he save the day?
As said earlier, when the captain enters the flight deck, he has clearly eared that the STALL warning has just stopped, so for him the worst is behind as the appropriate corrective actions have obviously been taken by the crew in place.
The STALL warning logic has just been playing a trick on him and his ability to rapidly and correctly apprehend the situation is greatly undermined.

These are two desperate pilots attempting to figure out INOP or problematic controls.
To the point that they will voluntary switch off 2 FCC in an attempt to regain control ...

The Airbus sidestick concept made their life miserable as no PNF(s) is able to directly witness what kind of inputs are applied on the sidestick(s), which contributes to this elusive loss of faith in the overall flight control system.

HazelNuts39

11th Mar 2013, 18:20

Lyman,

I wonder if you could help me find the captain suggesting "TRY CLIMBING" in the CVR transcript?

Lyman

11th Mar 2013, 18:29

Sorry, from memory, it was Robert, PNF who says "climb, then".

Captain says, "no, do not climb"? Then Robert, "then go down"? Then Bonin, "but i have been pulling" etc....?

My very bad...

BUT. They ALL know the NOSE is way UP. And NO ONE is thinking or saying, "PUSH FORWARD, and HOLD IT THERE"

It is not believable, and why I believe the accounts are "managed"

llagonne66

11th Mar 2013, 20:12

Here we are again !
The BEA, Airbus, Air France, the French government, etc. are engaged in delictuous activities to rob the unsuspecting public of the truth !!!!!

And of course all these organizations / countries are part of the conspiracy :ugh::ugh::ugh::ugh::ugh::ugh::ugh:
BEA final report page 19
In accordance with the provisions of Annex 13, Brazilian, American, British, German
and Senegalese accredited representatives were associated with the investigation
as the State of the engine manufacturer (NTSB) and because they were able to
supply essential information to the investigation (CENIPA, ANAC) or because they
provided assistance in the sea search phases (AAIB, BFU). The following countries
also nominated observers as some of their citizens were among the victims:
ˆˆ China,
ˆˆ Hungary,
ˆˆ Ireland,
ˆˆ Italy,
ˆˆ Korea,
ˆˆ Lebanon,
ˆˆ Morocco,
ˆˆ Norway,
ˆˆ Russia,
ˆˆ Switzerland.

HazelNuts39

11th Mar 2013, 20:24

Lyman,

At 02:12:44 the pitch is about level, the V/S is 15000 fpm, the stall warning is operating, and the captain says "(!) it's impossible".

If the nose is pointing up, the airplane should be going up, doesn't it? Hence the verbal confusion about going up or down. Are they talking of attitude or vertical speed?

Lyman

11th Mar 2013, 21:03

HazelNuts39

Both, I would say. What was Airspeed, I doubt Captain would claim "impossible" with only two cues?

If airspeed was <150knots, would he not command "Nose Down"? Where were the elevators at this time?

FTM, where was THS? But we know that, did he look? MAXNU? He might well be expressing chagrin at the THS' (apparent) lack of response "Why so 'stuck'....."

jcjeant

11th Mar 2013, 21:08

llagonne66
also nominated observers as some of their citizens were among the victimsIndeed ...
But .. for observe what ?
What were their powers?
What phases of the investigation do they have observed or potentially participate ?
Representative of French families have asked for an observer .. this was refused

HazelNuts39

11th Mar 2013, 21:18

Lyman,

Airspeed (indicated) had been around 60 kts, momentarily reached 150 kts at 02:12: 43. Elevators were at -15 degrees (NU).

Lyman

11th Mar 2013, 21:18

llagonne66

Dependent on which of the two circles you claim as residence, Where then is the data? The complete data?

There is no record of most of the record of the CVR, transcript or audio form.

Your question is not relevant, it has no benefit other than rhetoric. My question is a simple one, who has the record, is it available?

Can you answer that (honest) question?

My claim is not of conspiracy whatsoever. Someone has not released the data.

Prove me wrong? Until mine is answered, yours is merely an implication, unprovable.....

merci le cirque

Turbine D

11th Mar 2013, 21:51

Lyman,
At 02:12:44 the pitch is about level, the V/S is 15000 fpm, the stall warning is operating, and the captain says "(!) it's impossible".

As HazelNuts39 has pointed out the time listed above, the altitude was 20,028 ft. At 02:13:32, less than one minute later, the altitude was 10,092 ft.

It would seem to me that had the Captain recognized the situation at 02:12:44, that indeed they were fully stalled and falling fast, it was marginal the airplane could be saved applying significant nose down and holding it for a significant period of time. Less than a minute later, it became impossible. Debating the THS position, the elevator position, nose up, nose down, Side-stick visible, side-stick not visible, side-stick forward, side-stick back, it was too late. The Captain's words "it's impossible" prophetically applied to a possible recovery although I don't think that was what he was referring to at the time.

llagonne66

11th Mar 2013, 22:04

So much have been said over and over again that I can just go back almost two years ago.

http://www.pprune.org/6426258-post568.html

I have not changed my mind since that post.
Point taken : I should not have reacted to your unending ramblings about the BEA hiding the truth :O.
So please go on and on and on and on ... I'll watch from the shadows ;)

mm43

11th Mar 2013, 22:25

Of course, all the people involved in this tremendous feat have done all that just to tinker with the data contained in the boxes.I well remember your post. Like you, I have confidence that what has been provided by the BEA is and was relevant to the conduct of the flight. http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/infopop/icons/icon14.gif

HazelNuts39

11th Mar 2013, 22:25

Turbine D,

The captain recognized at 02:12:44 that they were fully stalled, and one minute later when the pitch attitude was 15 degrees NU he said only "no no no don't climb" ???

EDIT: If you recognize you are stalled there's only one thing to do: recover. At 20,000 ft you don't ask yourselves whether recovery is still possible.

Lyman

11th Mar 2013, 22:53

As HazelNuts39 has pointed out the time listed above, (2:12:44) the altitude was 20,028 ft. At 02:13:32, less than one minute later, the altitude was 10,092 ft.

At the first time, the VS was 15000. In about a minute, they fell only 10000.

That means the VS reduced substantially. Very substantially. What happened that was "Impossible" that drastically reduced their Vertical descent? Greatly increased forward velocity?

The lack of evidence, evidence that surely exists, would, I believe , provide answers. Answers that are invaluable to the safety of flight.

I do not believe in conspiracies, especially here. The lack of evidence is a fact. There is a demonstrable refusal to disclose the information. I could not care less the reasons for witholding it.

It is witheld, end of. That has f-all to do with sinister planning to commit a crime. (The legal definition of "criminal conspiracy").

Some imaginations are at high speed. One can accept the BEA report in the absence of full disclosure, or reject it. And anywhere in beween.

I do not trust it.

"The absence of FULL DISCLOSURE, is a species of FRAUD"

SUPREME COURT.....

HazelNuts39

11th Mar 2013, 23:07

What happened that was "Impossible" that drastically reduced their Vertical descent? Greatly increased forward velocity? Nothing drastic. Vertical speed reduced gradually. Air density?

Lyman

11th Mar 2013, 23:12

If VS reduced at a constant rate, would it not be ~5000 fpm at 10000 feet?

Averaging 10000fpm for that portion of vertical descent?

Would that have elicited some conversation in the cockpit?

Clandestino

11th Mar 2013, 23:17

The captain had no time to deal with the upset.He never realized what is going on in the first place. He had leaft flightdeck in order, nothing indicating this crossing of the ICTZ would be extra-ordinary and returned after first officers managed to stall the (allegedly, legendarily) unstallable.

He wouldn't have done what they did but came in too late to help. Just a guess but it might be a good one. Or not. Unlike NTSB that goes to great length to make a coherent picture of pilot's performance since first lessons by, BEA's info on pilots is remarkably scarce.

You instantly grok the attitude, ten degrees NU, and you proclaim, "Mon dieu mon petit chou, you have STALLED our cherie"....Hindsight is always 20/20.

you sense an immediate lessening of the chaotic airstreamDescription befitting a paperback novel but bearing no resemblance to anything recorded on CVR or DFDR. Unlike Stearman, all A330 currently in use are fitted with closed cockpit, therefore somewhat isolating the pilots from the elements. Airstream at high alpha and low speed would definitively sound different than it's usual in cruise but it takes quite a stretch of imagination to believe crew would recognize airstream as chaotic solely by listening to it. Especially as we're discussing the crews that didn't find warning computer shouting STALLSTALLSTALLSTALLSTALL worthy of comment.

They need to build experience, not just pushing buttons, but flying the aircraft.TT shows they were not inexperienced. All the other crews involved also had zero experience in manual handling of A330 in alternate law at high latitude yet none even dented their steeds. Experienced pilot also: stalled their aeroplanes fatally, lost controls, hit the ground they didn't know was there, ran out of fuel &c.

The general conclusion is that Captain cannot see the Stick, and assumes Bonin has Nose Down, input....That is very particular conclusion based on nothing but PPRuNe misinformation that stick positions are ueber-relevant.

These are two desperate pilots attempting to figure out INOP or problematic controls.Desperate -yes. Attempting to figure out anything and failing -yes. INOP or problematic controls - not at all. They worked as designed and obliged pilot's inputs dutifully into self-destruction.

BONIN has tried both NU AND ND,ND very briefly with rapid reversal back to NU as nose went down.

He is satisfied the controls are NOT WORKING.If so he was dead wrong, soon to be just dead.

It is IMPOSSIBLE that these two are on different pages,It is possible, it happens every day but seldom results in catastrophe.

they both know there is a problem, both have tried conformed, and reverse control positions.... What happened when stick went forward?

Is Bonin referring to loss of control BEFORE THE CLIMB?There was no loss of control before the climb. At least not in this local universe. Continuity of the controls and that aeroplane reacted to elevator movement up to splashdown is established beyond doubt.

I realize there are two related elements to the rate of response of nose position inputs: elevator command and THS trim both being part of the package in smoothly changing pitch attitude, and holding it.True but irrelevant. Do classic controls always produce the same aeroplane response for the same yoke displacement or it depends on weight, C.G., speed, altitude? Proper way to fly passenger transport aeroplane is by attitude indicator, not by feel. Who checks THS position on classics after take-off anyway? When required attitude and performance is achieved, residual trim force is trimmed out but notice taken of trim position after trimming - naaaaaaay.

As said earlier, when the captain enters the flight deck, he has clearly eared that the STALL warning has just stopped, so for him the worst is behind as the appropriate corrective actions have obviously been taken by the crew in place.Let the fact that unstalled aeroplanes don't fall from the sky at RoD in excess of 10 kilofeet per minute with nose held up high do not detract us from pursuing this interesting line of thought.

To the point that they will voluntary switch off 2 FCC in an attempt to regain control ...if indeed was so, their failing at that is unsurprising because controls worked all the time. They just could control themselves and eventually lost the control of the aeroplane.

The Airbus sidestick concept made their life miserable as no PNF(s) is able to directly witness what kind of inputs are applied on the sidestick(s), which contributes to this elusive loss of faith in the overall flight control system. By Jove, if this litany of yours ever becomes self-fulfilling prophecy by affecting someone so feebly-minded to believe it, you will have nothing to be proud about!

It is not believable, and why I believe the accounts are "managed" It is not believable to you.

But .. for observe what ?The investigation.

What were their powers?Power of objecting to investigation methods and results, which was not exercised. I must admit that this power is nothing compared to some posters' here special powers of pulling stunningly unrealistic hypotheses out of thin air.

Representative of French families have asked for an observer .. this was refused If French families signed The Convention on International Civil Aviation, there would be no reason to deny them the representative. Do you have a slightest idea what was the purpose and the legal status of the BEA investigation or are you just expressing amazement that the real world's arrangement is somewhat at odds with your notion of how it ought to be?

There is no record of most of the record of the CVR, transcript or audio form.Are you accusing BEA of falsifying the CVR transcript?

My question is a simple one, who has the record, is it available?BEA has original, anyone interested has transcript. If you have internet, you can download it too.

My claim is not of conspiracy whatsoever. Someone has not released the data.Data is released. too bad it was not to your liking. It just wasn't its purpose to satisfy anyone, it had to do something with improving the flight safety.

Lyman

11th Mar 2013, 23:33

Clandestino

Quote:
Originally Posted by Lyman
My question is a simple one, who has the record, is it available?

Clandestino:
BEA has original, anyone interested has transcript. If you have internet, you can download it too.

The entire transcript? Post it for us?

Many thanks

Turbine D

12th Mar 2013, 00:17

Lyman,
At the first time, the VS was 15000. In about a minute, they fell only 10000.
Don't know if you took Physics in High School or not, but there was a lesson some schools offered: If you drop a feather in a vacuum tube, it reaches the bottom of the tube at the same time as a marble (a tie). Add some atmosphere (air), the marble wins the race. Add even more atmosphere, the marble wins by a much bigger margin.

Now think about two feathers attached to a hay stalk falling flat in ever increasing atmosphere (more air). It falls ever slower during descent, as the air gets thicker creating more resistance, proving several important aspects of physics. Same is true of an A-330 falling nearly flat from 38,000 feet to 20,082 feet to 10,092 feet and on down.
If VS reduced at a constant rate, would it not be ~5000 fpm at 10000 feet?
It is not and that is why it is not ~5000 fpm at 10,000 feet.
That means the VS reduced substantially. Very substantially. What happened that was "Impossible" that drastically reduced their Vertical descent? Greatly increased forward velocity?
Ever denser air is a known fact.
Would that have elicited some conversation in the cockpit?
Is this part of the imagined "missing CVR record?"
"The absence of FULL DISCLOSURE, is a species of FRAUD"
Only if it is imagined but portrayed as being the whole truth and nothing but the truth.

Lyman

12th Mar 2013, 08:02

TurbineD

Quote:
That means the VS reduced substantially. Very substantially. What happened that was "Impossible" that drastically reduced their Vertical descent? Greatly increased forward velocity?

Air density is a known fact, so is 15000 fpm. I think it is possible Bonin is trying to "sell" overspeed to Captain. With flat Pitch and an increase to 15k in the descent, Bonin may be showing the Captain, "Look, Nose Down, greatly enhanced loss of altitude." He then "PULLS", and the VS decreases. Remember, speeds are not to be trusted, nor is STALL.... It is only us who know they read true.

These are desperate moments, the crew will try anything, and having never experienced a STALL in a large swept wing jet, who could fault their "ingenuity"?

I am trying to make a case for more understanding of this accident, not less.

You say air density, but that implies a passive crew...I think they were innovating, what else could they do?

If you are satisfied that the investigator is satisfied, fine. Throughout, the BEA leave avenues unsearched, and leave open (apparently) room for doubt.

They expect lack of interest to help them prove their case, and they get it.

Another approach could be: "This is everything we have, here are the possibilities." "here, there is great disagreement, shouting, so, this...."

The unending theme of this unsatisfactory conclusion is "Why"? Absent the fullness of data, that remains the height of injustice. The least fair of all settlements is Blame....And here, an opportunity to learn, squandered.

jcjeant

12th Mar 2013, 08:27

or are you just expressing amazement that the real world's arrangement is somewhat at odds with your notion of how it ought to be?Yes exactly
Those families (or representative) are one of the parties interested in the investigation process like are AF Airbus and others that can be added
They are also partie of the trial to come like AF Airbus and others that can be added ..
All but the representative of families have the right to be observers
Something unfair in The Convention on International Civil Aviation
If the representative of the families had the right to sign the convention .. be sure he will
Seems it's denied to them ...
And for the release of documents to public by BEA:
The FDR listing was never released (so far)

Clandestino

12th Mar 2013, 10:51

All but the representative of families have the right to be observersNot all, just the representatives of the ICAO member states that are considered to have interest in investigation such as countries where airframe, engines or systems manufacturers are located or if their citizens perished in the catastrophe.

And for the release of documents to public by BEA:
The FDR listing was never released (so far) What do you think we are basing our discussion of aeroplane's attitude altitude, control sticks and control surfaces positions on?

Something unfair in The Convention on International Civil AviationIf the representative of the families had the right to sign the convention .. be sure he will
Seems it's denied to them ...
Siiiiigh.... of course it is denied, they are not sovereign state interested in in having international air transport. Take E. Cochran's advice and take your problem to United Nations. They are the only ones that can do something about it.

BEA investigations are conducted in accordance with the provisions of Regulation No
996/2010 of the European Parliament and of the Council of 20 October 2010 on the
investigation and prevention of accidents and incidents in civil aviation.
The BEA is the French Civil Aviation Safety Investigation Authority. Its investigations are
conducted with the sole objective of improving aviation safety and are not intended
to apportion blame or liability. BEA investigations are independent, separate and are
conducted without prejudice to any judicial or administrative action that may be taken
to determine blame or liability.

Anything unclear about it?

jcjeant

12th Mar 2013, 14:59

What do you think we are basing our discussion of aeroplane's attitude altitude, control sticks and control surfaces positions on?On the graphics released by the BEA in the final report .. not on the FDR listing
Not all, just the representatives of the ICAO member states that are considered to have interest in investigation such as countries where airframe, engines or systems manufacturers are located or if their citizens perished in the catastrophe
So .. who is the representative of the ICAO for the french citizens who perished in this accident ?

DozyWannabe

12th Mar 2013, 17:55

Unlike NTSB that goes to great length to make a coherent picture of pilot's performance since first lessons by, BEA's info on pilots is remarkably scarce.

The NTSB is actually the outlier there. European agencies such as the AAIB and BEA tend to only reference crew performance as a whole. The NTSB has courted controversy in the past with individual crew performance assessments.

Throughout, the BEA leave avenues unsearched, and leave open (apparently) room for doubt.

Care to give us some examples?

On the graphics released by the BEA in the final report .. not on the FDR listing

The latter was the source data for the former. As has been asked before - are you asserting that the data has been manipulated, and on what grounds?

To the best of my knowledge, no accident investigation has released raw DFDR data in its entirety.

vapilot2004

12th Mar 2013, 18:15

Any representation of raw data in any other form other than the source numbers is manipulation unless the original scale is maintained and molestation of the timeline is avoided.

DozyWannabe

12th Mar 2013, 18:43

I don't think the scale and timeline have been altered to the best of my knowledge. Unfortunately the PDF conversion has rendered the graphs in a relatively low resolution, but they're still readable.

What I was getting at (as I'm sure you're aware) was whether certain posters believe that the data was deliberately altered to say something other than what was on the DFDR, and what reason they have for thinking that may be the case.

For the record, I think the data is genuine.

vapilot2004

12th Mar 2013, 19:17

Every DFDR/FDR data output set that I have ever laid eyes upon contains data points that do not fit the overall picture. Some are spurious and unavoidable due to monitoring and data collection system limitations and are rejected unless they fit a pattern under investigation. Other odd bits are known transducer noise anomalies. In a highly digital aircraft such as the Airbus or most modern Boeings, most of the raw transducer anomalies are filtered before they get to any exterior data bus. The DFDR, by virtue of its design, recording limitations, and things like the time slice paradox, does a bit of filtering itself.

Now, take what is left, and try to paint a perfectly accurate picture of exactly what was happening and when - it can't be done, however a reasonably accurate representation of the various parameters is what we have to work with, and in most cases, this is enough for forensic analysis.

On to the public release - the mere act of taking those fiddled numbers and placing them on a chart is once again a manipulation of the raw data. Subtle, and mostly innocuous, but the movement away from fidelity is incontrovertible and obvious to those who have seen the raw traces.

Lyman

12th Mar 2013, 19:43

Dozy

What I was getting at (as I'm sure you're aware) was whether certain posters believe that the data was deliberately altered to say something other than what was on the DFDR, and what reason they have for thinking that may be the case.

To me, It is not necessary to accuse anyone of anything. The report and its genesis are self explanatory. Without the fullness of the Data, in its entirety, the report is misleading beginning on its face page. Purposefully? I cannot say, but again that does not matter either. Everything in view is "interpreted", and left to the imagination.

What's left is what matters, corroboratory, exculpatory, and further room for doubt. What is not included would frame nicely the part that is published, right wrong or indifferent.

It is a "managed" document, apparently satisfactory for most, and dissatisfying for some....

Motive? Who gives a rats behind, the damage is done. "Intent" is loaded with nuance. Nuance has no business in a report that is intended to be a complete and factual record....

Were these gents actually that silent? Speaking prophetically and sparingly to a conclusion of their own incompetence? They had several minutes to bring to bear the sum of their 10000 hours.

It is the height of injustice to not allow them to be heard in the arena of fairness, by experts who can use discretion and somber reflection, toward a result of added wisdom.

They perished fighting a kind of flying that is rightfully held in awe, and fear, by sane and experienced transport pilots.

Their legacy deserves a hearing, by others than those who have thus far prevented one.

I do not wish to hear it. I wish for some neutral and wise party to judge and report what happened. BEA does not qualify in that regard.

That is why Data is necessary, to remove doubt.

DozyWannabe

12th Mar 2013, 20:04

most of the raw transducer anomalies are filtered before they get to any exterior data bus.

Or the instruments, as per design.

On to the public release - the mere act of taking those fiddled numbers and placing them on a chart is once again a manipulation of the raw data. Subtle, and mostly innocuous, but the movement away from fidelity is incontrovertible and obvious to those who have seen the raw traces.

The numbers aren't "fiddled". Filtered, maybe - but no more so than is normal for this kind of process and certainly not due to direct human intervention.

To me, It is not necessary to accuse anyone of anything. The report and its genesis are self explanatory. Without the fullness of the Data, in its entirety, the report is misleading beginning on its face page.

In which case every accident report ever published is, by your standards, "misleading" - as they are based on data sets no more precise than those supplied here and do not include a full dump of the FDR data as a matter of course.

It is a "managed" document, apparently satisfactory for most, and dissatisfying for some....

Same as for most accident reports. For example, the Spanish report on the 1977 Tenerife disaster was very unsatisfactory to the Dutch investigators, yet the veracity of that report is rarely, if ever, questioned.

It is the height of injustice to not allow them to be heard in the arena of fairness, by experts who can use discretion and somber reflection, toward a result of added wisdom.

So why are you not demanding the same for other accidents?

I do not wish to hear it. I wish for some neutral and wise party to judge and report what happened. BEA does not qualify in that regard.

Why does the BEA not qualify? Neutrality is in their charter!

jcjeant

12th Mar 2013, 20:08

To the best of my knowledge, no accident investigation has released raw DFDR data in its entirety.

Maybe not all the FDR but at least a big part (the most relevant for the accident)
Find here the Sharm El Sheik accident report (Egyptian report) with FDR listing (from pages 96 to 305!)
Download Report Charm pdf - upload, email & send large files up to 1GB for free! (http://verzend.be/ywqfs5eitu7u/Report-Charm-El.pdf.html)
And in France also .. FDR listings are sometime released to the public ...
Download Listing FDF France jpg - upload, email & send large files up to 1GB for free! (http://verzend.be/4t4uelrc2tmg/Listing-FDF-France.jpg.html)

DozyWannabe

12th Mar 2013, 20:29

Last time I tried to download those it tried to put a trojan on my computer. Hopefully I'll have more luck this time...

I note that the second (French) document dates to 1990. Given that there were far fewer methods at that time to render such data graphically and in an easily-readable format, could it not be that the graphical method used by the BEA now is simply a tool of convenience?

Lyman

12th Mar 2013, 20:29

Whether you accept it or no, the BEA fail neutrality and wisdom both, by definition, and at Law.

They are an arm of the FRENCH government, which has an enormous stake in the outcome. There are economic and political repercussions.

BEA themselves would demur as to wisdom, for wisdom bears judgment, and BEA may not judge.

My opinion.

vapilot2004

12th Mar 2013, 20:32

Or the instruments, as per design.]

Precisely, my friend.

The numbers aren't "fiddled". Filtered, maybe - but no more so than is normal for this kind of process and certainly not due to direct human intervention.

Both words describe an alteration, or better, interpretation if you will, of the raw numbers. Perhaps one has a negative connotation that should be avoided?

Turbine D

12th Mar 2013, 20:36

Lyman,
I am trying to make a case for more understanding of this accident, not less.
It seems to me you are taking the case where the basic facts of the cause of this accident are well understood and attempting to make them less understood with your unsubstantiated theories, imagination and innuendoes.
Below is the released data, CVR and FDR from the BEA. That's all there is. In the absence of the Captain, the PF & the PNF stalled the airplane, never figured out they were stalled and upon the return of the Captain, he couldn't unravel what had taken place and what was happening in time to make a difference.

http://www.bea.aero/docspa/2009/f-cp090601.en/pdf/annexe.01.en.pdf

http://www.bea.aero/docspa/2009/f-cp090601.en/pdf/annexe.02.en.pdf
And here, an opportunity to learn, squandered.
I don't agree. It has certainly focused attention on high altitude, high speed manual flying as well as what to do and not do should UAS suddenly happen. So far, there has not been a repeat so there has been learning going on, one would think, not all has been squandered.

DozyWannabe

12th Mar 2013, 20:46

They are an arm of the FRENCH government, which has an enormous stake in the outcome.

What stake would that be? The A330 is already a success in financial terms and the pan-European Airbus consortium is going toe-to-toe with Boeing in the global airliner market. How would the outcome of this investigation change that?

I ask again, are you insinuating the BEA's complicity in a cover-up?

There are economic and political repercussions.

No more or less than any other commercial aviation disaster.

BEA may not judge.

They have no legal say - however as with every other accident investigation bureau they are required to make a judgement call on the technical and human factors surrounding the accident.

Both words describe an alteration, or better, interpretation if you will, of the raw numbers. Perhaps one has a negative connotation that should be avoided?

It's not an alteration of the numbers (as they came out of the DFDR), it is simply a graphical rendering*.

* - Which in turn allows them to present the same amount of data that would take thousands of pages rendered numerically into less than ten pages graphically.

Lonewolf_50

12th Mar 2013, 21:31

True but irrelevant. Do classic controls always produce the same aeroplane response for the same yoke displacement or it depends on weight, C.G., speed, altitude? Proper way to fly passenger transport aeroplane is by attitude indicator, not by feel.
No kidding? I do know how to fly, I do know how to fly on instruments, and I am aware of how modern flight control systems have response rates. I used to have to check them for delivery, according to a spec.
Who checks THS position on classics after take-off anyway?
Why are you asking me? The "position of THS" beacme a topic of discussion in re AF 447, and some of the folks in this discussion feel that the THS ended up impeding the recovery. I am not in that camp.

You comment to me there is not on point, as I was referring to response rates, a feature which will be found in any aircraft that has hydraulic/electro mechanisms in the linkages between pilot input and flight control surface movement. As I understand it from those folks who fly the A330, the response rates are just fine in normal flying. No surprise, I imagine the AB engineers and test pilots did a lot of work together to get that "just right" before deliveries started ...
When required attitude and performance is achieved, residual trim force is trimmed out but notice taken of trim position after trimming - naaaaaaay.
Thanks for that, but I already know that.

Cheers.

DozyWannabe

12th Mar 2013, 21:45

LW_50, I suspect that while Clandestino's point is referring to your post he is - as usual - addressing the gallery and not you specifically. As far as I can tell you're singing from the same hymn sheet, and I wouldn't take it personally.

For good or for ill, he does tend to go off like a hand-grenade!

Lyman

13th Mar 2013, 00:03

Dozy you make some good points re: the report.

It is what it is. I have high expectations, and am irritated at the "sole source" aspect of the system as expressed currently. It has the flavor of secrecy, something that is repellent in a free society.

It does not feel or appear right that evidence can go unseen by all but one group. I would favor an Ombudsman to represent neutrality. Certainly at the level of International Aero Commerce....

Whether or not there was bias, the system is set up to create the appearance of prejudice, at least to me.

It's been a great ride, thank you for all the energetic point counterpoint. I do not know about you but I have learned alot, and you have been a source of some of that new knowledge, so thanks....

DozyWannabe

13th Mar 2013, 00:22

Dozy you make some good points re: the report.

Cheers.

It is what it is. I have high expectations, and am irritated at the "sole source" aspect of the system as expressed currently. It has the flavor of secrecy, something that is repellent in a free society.

How so? The only reason the BEA has been the primary investigatory agency with little outside influence is because no other agency has asked to join in at that level. Don't forget that in the case of the Mt. St. Odile accident (probably mindful of the press assertions regarding AF296) the BEA invited an NTSB team in to check their work.

Whether or not there was bias, the system is set up to create the appearance of prejudice, at least to me.

And yet the NTSB has been the sole investigatory authority for US-made airframes flown by US-based airlines for decades without similar aspersions being cast - why the double standard?

There's a scar in the earth of the Ermenonville forest just north of Paris that serves as a constant reminder to the French of the folly of sweeping airliner design problems under the carpet. To this day it still pushes bits of metal and bone to the surface. It's a lesson that only needs to be taught once.

jcjeant

13th Mar 2013, 08:57

It's not an alteration of the numbers (as they came out of the DFDR), it is simply a graphical rendering*.

* - Which in turn allows them to present the same amount of data that would take thousands of pages rendered numerically into less than ten pages graphically.

It seems to me that the BEA believes he is a journalist
The graphic is their press article and their source is the FDR listing
You can not force a journalist to give his source .. because it is protected by law :}

Lonewolf_50

13th Mar 2013, 12:16

Dozy: I understand and see something similar. What I fell needs an answer is taking a comment I make somewhat out of context.

DozyWannabe

13th Mar 2013, 13:23

@jcj:

Not quite - the data is verbatim from the DFDR, it's just rendered differently - i.e. the formatting has changed but the data has not. Ironically, you could make a case that it's like what passes for "journalism" these days (i.e. slapping a byline on a pre-written press release and leaving it unchanged), but that's different. :ok:

@LW_50:

Sure, and he's misrepresented me once or twice in the heat of the moment - he's usually happy to take it back though, and I'd much rather have him inside the tent than outside! ;)

Lyman

13th Mar 2013, 15:18

Dozy

And yet the NTSB has been the sole investigatory authority for US-made airframes flown by US-based airlines for decades without similar aspersions being cast - why the double standard?

You create the double standard by defining it, and you haven't let me agree. There is no difference in the lack of suitability NTSB/BEA to perform their mission.

The environment for both is populated by people whose job descriptions are written by other people, similarly situated....

The conflict is glaringly obvious, to deny it, is, well, denial....

These folks are BUDS. It is not fair to demand intellectul isolation of the investigators from their confreres. It goes against human nature, and in and of itself creates the conflict.

Assuming people can easily transform themselves into Solomon, is patently ridicilous, and childish.

"Ombudsman"......eliminating the potential, and hence reality, of conflicts.

"Peer".....QED

DozyWannabe

13th Mar 2013, 16:01

These folks are BUDS. It is not fair to demand intellectul isolation of the investigators from their confreres. It goes against human nature, and in and of itself creates the conflict.

I disagree. Separating one's personal relationship from the working relationship is Professionalism 101, and in the case of aviation it's even more important to do so. Making sure that your colleagues do the right thing, and in turn allowing them to do the same for you should not be subject to whether you like each other, because in a heavily interdependent organisation getting it wrong lets the team down.

"Ombudsman"......eliminating the potential, and hence reality, of conflicts.

It could be argued that the BEA, NTSB and AAIB fill that role for their regulatory counterparts (i.e. DGAC, FAA and UK CAA) - it's why they were made independent in the first place. Prior to this, political and personal factors allowed standards to slip and it always ended in tears.

One major limitation to this system is that the investigatory agencies only come into play after something has gone wrong - Air France's troubled recent history was well-known amongst the piloting fraternity, but it took something drastic to allow the BEA to investigate. Another limitation is that the regulators cannot be compelled to act on the recommendations of the investigators, but that's for another time.

Turbine D

13th Mar 2013, 16:35

Lyman,
There is no difference in the lack of suitability NTSB/BEA to perform their mission.
If not the NTSB or BEA, who, in your mind should do airline/aircraft accident investigations? What would be the make up of that organization in terms of expertise?

Lyman

13th Mar 2013, 16:43

Somebody like "ExPonent, Failure Analysis Associates", in Menlo Park, California.

Or RTCA, who published strict rules for Lithium Ion Batteries, which Boeing then completely ignored, relying instead on their own in house generated "special conditions".....Which they then failed completely, because the authority, FAA, allowed them to certify themselves?

But certainly a private and independent entity, some one who is not paid by the people who compose their mission statement....(Congress).

Who would you choose? Some one who receives Lobby Money, or someone who is paid out of independently managed and scrutinized funds? Subject to independent Grand Jury Audit, at random?

:ok:

May I submit for the approval of the assembly the most egregious and flagrant "OXYMORON" known to mankind?

"CONGRESSIONAL OVERSIGHT"

DozyWannabe

13th Mar 2013, 17:39

Yeah - 'cos whoever heard of a private entity being corrupt? :rolleyes:

Look - while the independent agencies are funded by the various governments, the funds ultimately come from taxes paid by (among others) the people of the country. Ultimately it's those people those agencies are answerable to, because they are chartered to ensure their safety. Imperfect as it is, I for one have more faith in that social compact than I would in a for-profit organisation trying to do the same.

Lyman

13th Mar 2013, 18:00

Dozy

You my friend, have two annoying idiosyncratic tendencies.

First, your habit is to respond to a post that is in conversation with two other parties.

Second, you jump in and defend or attack an exchange of semi personal flavor involving others.

Oh, and three.

Your belief, without question, is that your mere disagreement with another poster is sufficient to successfully extinguish the other position.

I charge it off to exuberance.

Meet me at the TechLog thread Batteries and Chargers, and we will discuss the utter incompetence and blatant conflict of interest of the two American entities, NTSB and FAA.

I would like to bid adieu to this thread, pending the ultimate release of the complete data by BEA.

DozyWannabe

13th Mar 2013, 18:13

Hey Bill,

Firstly, all forum discussions are group discussions - so I, or for that matter anyone else, should be free to contribute at will. The PM system exists for more private discussions. Secondly, my opinion is just that - I don't ascribe myself psychic abilities or consider my word on any matter final; if you choose to read me this way then I suggest you're reading me wrong.

Finally, the 787 issues have not involved the NTSB at any point, because the NTSB can only become involved in the event of an accident or serious incident (usually involving injury). Don't make the mistake of assuming that because they are both government agencies they get their marching orders from the same people.

Lyman

13th Mar 2013, 18:34

Finally, the 787 issues have not involved the NTSB at any point, because the NTSB can only become involved in the event of an accident or serious incident (usually involving injury).

Sorry?

Enough OT, out

Turbine D

13th Mar 2013, 19:05

Lyman,
Somebody like "ExPonent, Failure Analysis Associates", in Menlo Park, California.
And,
Who would you choose?
It is a small world out there in the accident investigating field. Most private firms wouldn't have the capability to do a complex investigation on their own. Exponent does have a person knowledgable in transportation investigations according to their web page:
Dr. Dickinson specializes in transportation related issues, particularly accident reconstruction and safety analysis of transportation related products, systems and installations. He has had extensive experience spearheading many investigations of major transportation related accidents and failures, and his current research focuses on urban transport studies, safety analysis of railroad equipment and operations, evaluation of aviation safety and air traffic control. Dr. Dickinson is a former member of the National Transportation Safety Board and held several engineering and research positions before joining Exponent.
Exponent was used by the NTSB in the investigations of TWA800 and AA587. They were also used in the Turkish Airlines 981 accident investigation lead by a French Commission of Inquiry appointed by the Minister for Transportation.

Personally, I am generally satisfied with the way the NTSB does their investigations and don't see the advantage of taking this function private. OTOH, I think the FAA could do a better job when given recommendations by the NTSB.

Lyman

13th Mar 2013, 19:28

Hi TD

Personally, I am generally satisfied with the way the NTSB does their investigations and don't see the advantage of taking this function private. OTOH, I think the FAA could do a better job when given recommendations by the NTSB.

Yep. The only current gripe I have re: NTSB is that its chief, Deborah Hersman, is at the top of a short list to head the Department of Transportaton for President Obama. The current chief resigned just after the grounding of 787, but was pressured into staying on, to avoid making Boeing look bad.

As to FAA, my recommendation is to scrap the entire agency, with prejudice ("and don't come back").....

I favor a review of NTSB findings, why not? Second opinions are de rigeur in other important realms.

FAA should be a legal and administrative agency/entity, familiar with transport law, risk manaagement, and safety issues, not "to promote Aviation" (from the FAA charter, I kid you not)

henra

13th Mar 2013, 20:46

As to FAA, my recommendation is to scrap the entire agency, with prejudice ("and don't come back").....

and

not "to promote Aviation" (from the FAA charter, I kid you not)

This is one of the (unfortunately) not so frequent occurrences where I absolutely have to agree with you!

Sometimes I have the feeling the last sentence should in reality even read it is "to promote Aviation INDUSTRY". Joe public doesn't seem to rank terribly high on their agenda...

That said, your bashing/mistrust of NTSB on the other hand I don't share.
They have often stated unfavourable/critical things regarding aircraft/airlines/other companies only to be later ignored by FAA.

KBPsen

13th Mar 2013, 21:14

Quote:
not "to promote Aviation" (from the FAA charter, I kid you not)
This is one of the (unfortunately) not so frequent occurrences where I absolutely have to agree with you!That is neither here nor there. You are all falling for the bait. Lyman/Bearfoil/Airfoilmod/Will Fraser etc. is simply here to perpetuate an argument.It does not matter what is right or wrong, what is truth or opinion. All that matters is impugning anything that can be seen as authority and maintaining a perpetual argument

This is nothing but a rerun of an attention seeking individual.

bubbers44

13th Mar 2013, 21:25

TWA 800 was the worst case of NTSB manipulating the final center fuel tank explosion as the cause of the crash. All observers of how it happened were disregarded to make their case. They decided to make the cause of crash what they wanted and worked backwords to make it seem logical.

Lonewolf_50

13th Mar 2013, 22:37

KBPsen: we are occasionally advised to play the ball not the man. ;)

Bubbers: what, was Salinger right? Was it an Aegis cruiser shooting an SM-2 missile that really brought it down? :eek:

KBPsen

13th Mar 2013, 23:20

Lonewolf, every conflict is not your responsibility, so you do not have to resolve all.. Grow up.

Lonewolf_50

13th Mar 2013, 23:27

Lonewolf, every conflict is not your responsibility, so you do not have to resolve all.
No quibble with that observation. Trying to be a peacemaker.
Grow up.
Play the ball, not the man ... boy.

Guess it didn't work. May have to do with pigs and sows's ears. :p

john_tullamarine

13th Mar 2013, 23:31

Folks, can we keep ourselves nice, please ? Lest the sword be wielded.

vapilot2004

14th Mar 2013, 05:30

It's not an alteration of the numbers (as they came out of the DFDR), it is simply a graphical rendering*.

Please see bold from my post:

Both words describe an alteration, or better, interpretation if you will, of the raw numbers. Perhaps one has a negative connotation that should be avoided?

Contrary to what we might like to believe, not all of the report production process in an accident investigative body uses objective thinking. This includes part of the process when plotting the numbers onto graphs.

Lonewolf_50

14th Mar 2013, 13:03

Lyman

14th Mar 2013, 13:59

TurbineD

I was involved (at the investigative level) in a fatal motor vehicle accident (MVA). The client was charged with Vehicular manslaughter and looking at 15 years in prison.

The Official Report by the Highway Patrol was damning, and on the face of it, impenetrable. My partner, through diligent research, found record of an interview done by the State investigator. The eyewitness was a registered Nurse, and first on the scene, performing unfortunately unsuccessful resuscitative work on the dying victim.

The record of the interview was nowhere to be found in the Official Report.

The witness was incredulous, "They did not quote my statements?"

Fifteen minutes after the District Attorney found out that the witness had been found, and was willing to testify at Trial, he dropped all charges.

NOTHING in the Official Report was false. It portrayed a slam dunk case of manslaughter. One piece of evidence, excluded from the report, (when "found"), trashed the Official report to smithereens.

The eyewitness report was wilfully and illegally hidden, suppressed.
There was no reason to support a charge of felony obstruction, the person who hid the interview was someone who would participate in many more actions, and one needed to be circumspect about those kinds of things. We were happy with the dismissal, and satisfied that "Justice" had been won.

I do NOT charge misfeasance; BEA has released a FINAL report, no one may ever know what is in the full record. Probably nothing of importance.

Confucius: "A Half Truth is a Whole Lie".

Trust in GOD, all others must disclose....

roulishollandais

14th Mar 2013, 18:07

@ Lonewolf_50, Turbine D, DozyWannabe, Other

I agree with Lyman and vapilot2004 conclusions for that reason :

CVR and Witness report are in NATURAL LANGUAGE , a NON-CONTEXT-FREE language. So you cannot replace or modify them.:=

Not modified CVR and Witness report bring us not only the FORMAL CONTEXT-FREE words but also the Context which helps us to understand the words and semantic of NATURAL LANGUAGE of the Crew and of the Witness.

It is the main difference between Human and software production.

Lonewolf_50

15th Mar 2013, 14:02

Roul, thank you. I am on board with that challenge to any investigation.

While that applies to the CVR, I was asking va about FDR and raw data interpretation. ;)

SeenItAll

15th Mar 2013, 14:13

Evidently Airbus is complaining that no one has been able to design a simulator to accurately replicate the conditions after an aircraft loses lift, or stalls -- and that this means that more non-simulator training needs to take place.

http://http://www.bloomberg.com/news/2013-03-15/airbus-test-pilot-says-air-france-crash-has-simulators-stumped.html?cmpid=yhoo

jcjeant

15th Mar 2013, 14:32

Good link to Bloomberg news !
Airbus Test Pilot Says Air France Crash Defeats Simulators - Bloomberg (http://www.bloomberg.com/news/2013-03-15/airbus-test-pilot-says-air-france-crash-has-simulators-stumped.html?cmpid=yhoo)
Engineers are also exploring whether a plane could be better protected after a stall by expanding the use of computer- generated responses even when control reverts to its pilots following the receipt of conflicting information, as happened in the Air France crash. I can be wrong .. but I think that the Boeing F/A-18 Hornet have such automatism (Auto spin or stall recovery)
Maybe Gums can tell us more about ...

Lyman

15th Mar 2013, 14:42

My understanding of the F/A18 is that at low speed, (0, on the catapult) and "departed" the hand must be off the stick....

The Pilot must "Let go", the aircraft recovers (launches) itself.....

gums?

jcjeant

15th Mar 2013, 16:46

OK .. I'm wrong
Hands off !!
QSLmblzI_c4

vapilot2004

15th Mar 2013, 18:48

vapilot: given that most raw data needs a bit of interpretation, should we toss into the bin, then, all FDR based analysis, deliberation, and conclusion? (I doubt you feel that way.)

When it comes to data, most of the major bureaus and boards only publish enough data to illustrate their focused areas of concern, leaving out the obvious unneeded stuff, which is perfectly fine, but also omitting that which fails to support their thesis - not unlike the modus operandi of a criminal defense attorney or a skilled prosecutor. Although looked down upon in the scientific world, it remains a common practice even within these trusted agencies. Blame it on pride, human nature, or whatever you desire. Some are better at 'full disclosure' than others, and history has taught me that within the same agency (NTSB) some investigations are more thorough and forthcoming than others.

Does the BEA's analysis not achieve the "good enough" standard in this investigation?

Since the AF447 readouts are unpublished and remain under lock and key - unobtainable even to those parties on the inside with a vested interest in the investigation - and what was published was cherry-picked, I can't say whether the BEA's analysis was good or bad. What I can say is there are a multitude of unpublished areas, both temporal and in selected data channel, that everyone should be able to examine in order to better understand what the aircraft was doing, what the automatics were doing, and what the pilots saw on their instrument displays.

HazelNuts39

15th Mar 2013, 19:55

What I can say is there are a multitude of unpublished areas, both temporal and in selected data channel It would be easier to understand your discourse, if you could tell us what those areas are.

Lyman

15th Mar 2013, 20:18

It strikes me as uncharacteristic of you to ask a loaded question, HazelNuts39.

If one has not seen something, how is it possible to index it for you?

HazelNuts39

15th Mar 2013, 20:38

Lyman,

How can one say "there are a multitude of unpublished areas" if one has not seen anything? Speaking in generalities is useless, specific 'omissions' can be discussed.

" what the aircraft was doing, what the automatics were doing, and what the pilots saw on their instrument displays" is all extensively discussed in the report, with all the relevant data as recorded. I really am at a loss what data could possibly be added to better understand those topics. "What the pilots saw" is asking what went on in their minds, and that was not recorded.

jcjeant

15th Mar 2013, 20:52

The only hope of knowing what has "not been made public" so far is that it will probably be made public during the trial
Indeed, the judge may require all documents he deems necessary to establish the judicial truth .. it is in his power

Lyman

15th Mar 2013, 21:21

HazelNuts39

I cannot believe we are having this discussion. Early: "Here, and Here, you go up, so go down..." "You climb, so go down..." 'Eh, what are you doing..."

Either you believe there is nothing of value in the CVR, and BEA have divulged what they have, without comment. Or you think and trust that BEA should be the be all and end all, of inflection, tone, vocabulary, etc. I do not trust anyone to interpret evidence for me. If I am privy to knowledge of dangerous behaviour by an airline, crew, or equipment, it is my RIGHT to make an informed conclusion, after assessing the evidence, for myself.

I have my reasons, as do others, for not being so trusting. I do not for one thing believe in a "sole source", when it comes to Public safety. I have seen enough of that that backfired on the investigation, and even led to prosecution for serious "errors" of "judgment"...

It is a fundamental of Western society that an accused be allowed to face his accusers, and testify on his behalf in any proceeding. The CVR is the last eyewitness account of an accident that has value for all of us regarding furthering the cause of safety, not to mention the reputations and state of mind of the crew....

What is it about the Truth that you do not feel obliged to seek? Do you believe the report is scrupulously complete, and without bias? It is impossible, without knowing the evidence, in my opinion, to know these things.

For one reason or another, this crash is charged as a crime, manslaughter. With holding evidence is a crime in and of itself, imo.

I have no idea the reputation of this source... But the MAIL ONLINE claims DuBois was heard claiming he had but one hour rest the night before the flight....

HazelNuts39

15th Mar 2013, 22:08

Lyman,

There are three recorded 'data channels' - the ACARS messages, the DFDR data, and the CVR. The DFDR tells us what the pilot did with the controls, and what the airplane did in response. The two have been correlated, and there is no open question about those. The DFDR data, together with the information gathered by BEA, tells us what the automatics were doing. It was extensively discussed on this forum. I'm not aware of any open questions in that area, except the behavior of the flight directors, but that was not recorded. The DFDR also tells us most of the information available to the pilots on their displays and BEA has reconstructed as far as possible the missing parts. Where that was not possible, the information was not recorded.

We do not know what the pilots saw because it was not recorded what they were looking at, nor how their brains processed what they saw. The CVR tells us what they told each other, and what other sounds there were in the cockpit. True, that information is too scarce to enable us to fully understand their mental processes, why they acted the way they did. If they had said more, maybe we would better understand what they did. But, if they said more, how could it be in anybody's interest to hide that?

Lyman

15th Mar 2013, 22:27

They did say more. You will say they did not. BEA have said nothing either way...

You are satisfied with that. My experience instructs me to ask for proof...

A graph of any kind can be erratic, inexplicit, and misinterpreted. Raw data, all of it....thank you.

Clandestino

16th Mar 2013, 00:10

I think that the Boeing F/A-18 Hornet have such automatism (Auto spin or stall recovery)Recovery is automatic but it has to be initiated manually via switch, at least on A-D models. Pilot has to be aware he lost control and has to admit to himself he doesn't know how to regain it.

Evidently Airbus is complaining that no one has been able to design a simulator to accurately replicate the conditions after an aircraft loses lift, or stalls Nope, it is ignorant misinterpretation of what Airbus said. Simulators accurately replicate the conditions for which there are collected data and that includes couple of degrees beyond alpha crit on 330 but certainly there is no requirement to get transport aeroplane to 45° AoA or test pilot suicidal enough to try it.

True, that information is too scarce to enable us to fully understand their mental processesCorrect, but the scarcity of info is info in itself - not to show there is some conspiracy with BEA deliberately falsifying the CVR transcripts but that the crew was so shocked there is no clear verbalization of what they think is going on.

How can one say "there are a multitude of unpublished areas" if one has not seen anything?Simply, if one's intention is not to discuss meaningfully but rather to elicit a reaction.

mm43

16th Mar 2013, 00:26

They did say more.I can agree with you there.

Some of what they said has been deemed irrelevant to the investigation, while on the otherhand, the speech tone and/or intonation imparted may in itself provide some additional clues. The BEA have in IMO avoided making those calls, as to do so would create further dispute over the rights or wrongs of such judgements.

Patience is a virtue, and the criminal trial programed for sometime in the future may eventually establish a little more about the situation in the cockpit that night, not that it will ever change the substance of the BEA's Final Report.

Clandestino

16th Mar 2013, 00:29

They did say more.

I can agree with you there.

Based on what?

mm43

16th Mar 2013, 00:43

Based on what?( ) Words or group of words whose meaning has not been identified with certainty. The “ / “ symbol gives various proposals.
(…) Word or group of words with no bearing on the flight
(!) Curse
(*) Words or groups of words not understood

I have read the CVR transcript - just like you, and the reasons I gave for my statement followed the piece you quoted.:D

Lyman

16th Mar 2013, 17:48

From A320Driver, on the RN thread (447)

According to a report on the Italian Corriere della Sera, at some point before he went for in flight rest, the Commander had said something to the effect hat he had not slept enough the previous night and that one hour sleep is not enough.

I also found that in the Daily Mail, from Ben's site.

If that is from the CVR, (how?) Then BEA should be removed from any role in the further investigation of the flight, and another impartial entity be appointed.

And they should relinquish all evidence. Criminal prosecution should ensue.

jcjeant

16th Mar 2013, 17:56

About fatigue .. this what all I find in the BEA final report:
Note:
Bold added by me
1.16.7 Aspects relating to fatigue
The professional timetable of the three crew members during the month that
preceded the accident flight shows that the limitations on flight and duty times, as
well as rest times, were in accordance with the provisions of European Regulation
(EC) n°859/2008 of the European Commission (sub-section Q of Annex III).
The investigation was not able to determine exactly the activities of the flight crew
members during the stopover in Rio, where the crew had arrived three days earlier. It was not possible to obtain data on their sleep during this stopover.
This lack of precise information on their activity during the stopover, in particular in
relation to sleep, makes it impossible to evaluate the level of fatigue associated to
the flight crew’s duty time.
The CVR recording does, however, make it possible to show that the crew showed no
signs of objective fatigue, as the following elements indicate:
ˆ The level of activity and implication of the augmented crew in the first part of
the flight, with the Captain and the copilot seated in the right seat, then in the
second part of the flight with the two copilots, are in accordance with what is
expected from a crew in the cruise phase. No signs of drowsiness or sleepiness
are noticeable;
ˆ At 0 h 58 min 07, the Captain was concerned with the state of fatigue of the
copilot in the right seat. («try maybe to sleep twenty minutes when he comes
back or before if you want ») who answered that he didn’t want to sleep;
ˆ Questioned on his return to the cockpit, the copilot who took the Captain’s place
answered that he had “dozed”.
Seems the judicial experts have more infos about fatigue in their report ..

Chris Scott

16th Mar 2013, 18:40

The only inference I can draw from this current discussion is that a few forumites are in effect demanding that the BEA should release the CVR sound track in its entirety, so that it can be broadcast on the www for public judgement and therefore, inevitably, prurient entertainment. Unlike the investigators, they seem to care little of the human consequences, and would carry no responsibilty for them.

They represent the school of the blame and shame culture - the modern equivalent of those who relished the spectacle of the guillotine, or pelted with rotten eggs the petty criminal in the stocks. To them an investigation is a tool for litigation; not for learning. Finally recovered from the trauma of realising that their crazy assertions about the demise of AF447, and the conduct of the search, were discredited, they employ weasel words to imply that the BEA is conspiring to pervert the cause of justice for the deceased.

Those who constantly protest for the truth, but deny it even when it is staring them in the face, include the usual suspects. They know who they are. They have never worked in an airliner cockpit, nor on the bridge of a ship, and appear to have no experience or even understanding of the balance between authority and responsibility in a safety-critical operation. Just as well, for their cavalier indifference to rational thought, combined with obsessive attention seeking, would be a lethal combination. Their constant carping has slowly betrayed their agenda, which even they no longer believe to be compatible with the established facts.

The truth is that no degree of revelation would silence their accusations of tampering of the data and other evidence, and it is impossible to prove a negative. Releasing the CVR audio channels for public consumption would be an immoral act. It would also persuade most flight crew that installing cockpit videos would be an intolerable step. Their arguments are not worthy of consideration.