AF 447 Thread No. 10 [Archive] - Page 3

PJ2

25th Sep 2012, 15:53

Hunter58;

Thanks for your response.

Regarding "management" and "Flight Operations Management" - First, as the CEO goes so goes the airline's corporate culture and priorities. If the CEO broadcasts that he or she will not tolerate compromise in safety standards and demands a healthy safety reporting culture, it will happen. If the CEO broadcasts the view that cost-control-at-all-cost is the priority, his lieutenants will ride out and do the CEOs bidding. It is the way bureaucracy, job security, promotion, and egos, work. The airline/corporate culture adopts the approach that the CEO broadcasts.

If the CEO does not have a comprehension of the aviation business and, more importantly, what keeps it safe, then there is little that operations, the safety department or the broader culture can do to counter picayune priorities that are set by the executive leadership.

The unspoken but not subtle belief conveyed is, "the business has to stay in business", and where there is normalization of deviance (cutting corners, "doing the right thing according to corporate values especially where there are no untoward outcomes), that is the corporate culture that will grow and which becomes "invisible" because it is "the way we do things." In such a culture, a serious incident or accident is unexpected and therefore is always a complete surprise, and blame not comprehension is the usual outcome in such cultures.

Now within that structure, certainly senior management, even operations management, can retard the retreat towards pure cost control, (which takes safety for granted). In fact in my experience that's how it works, to a greater/lesser degree. Those in the business know that a perfectly safe operation isn't possible without staying on the ground but running the business does not afford the time to understand..."there's a business to run". I have known CEOs who had absolutely no clue how flight safety actually worked to keep their aviation business safe - the apparent comprehension appeared in discussion and in print from the executive offices to be at the very rudimentary "have everyone wear safety vests while on the ramp" level. There was little understanding at senior management levels of the notion of the organizational accident, threat-and-error management and the importance of the basics, (as per Lonewolf_50's post).

Operations may be at the coal face and may be the only ones who truly comprehend what is required in an ongoing safety culture but if Operations does not have the active, involved support of the CEO, then they are limited, primarily by stature, (meaning, Marketing is more privileged than Operations or Maintenance), within the corporation and by budget contraints (and the subtle pressures which attend such dynamics) in their effectiveness and ability. In such cultures, flight safety departments are usually viewed as dead-end career-path choices.

These situations aren't static of course. People change with new awarenesses and I saw that too. The flight data program, very late in coming, was ignored for years until that kind of behaviour actually became a liability. When something showed up in the data they wanted to know "who that pilot was" so they still didn't get it. In this particular example data is slowly being valued and makes changes in SOPs so change does occur.

What is obvious to those who do flight safety work is not at all obvious to those who must run the business, and vice versa. That's neither good nor bad, it's a challenge...for both groups.

roulishollandais

25th Sep 2012, 18:10

Today the Cassation Court of France said in a definitive decision going against the General Prosecutor opinion, on Request from international lawyer Daniel Soulez Lariviere, that France Court could judge a criminal case who happened out of the French Waters.
All the men of the chain have been said culprit.

This decision is an important point for AF447 and the future aviation crashes.

The law of the "for" finds an important and safe precision, with safe independance of Judges for transport cases

PJ2

25th Sep 2012, 18:17

roulishollandais;

Thank you for this information.

"This decision is an important point for AF447 and the future aviation crashes."

Indeed.

Lonewolf_50

25th Sep 2012, 18:28

I would have been much surprised had they ruled otherwise.

(sotto voce ... do you think they want to cede jurisdiction to someone else? :E )

Lyman

25th Sep 2012, 18:54

Strictly speaking, Lonewolf, it is not "theirs" to "cede".

Imo

Lonewolf_50

25th Sep 2012, 19:17

Lyman, I see your point, but I was looking at it thusly:

if they assert jurisdiction, someone else has to take the time and effort to show that it isn't theirs.

Conversely, if they don't assert jurisdiction, who has it? :confused:

mm43

25th Sep 2012, 19:38

The following Reuters Article (http://www.reuters.com/article/2012/09/25/france-erika-idUSL5E8KP8Y320120925) refers to the Cour de Cassation ruling which held the giant French oil company Total responsible in both the criminal and civil domains for damage caused when the Italian oil tanker "Erika" split in two in 1999 and sank off the French coast, but in international waters. The environmental damage was severe, but Total had argued that it had only chartered the vessel and was therefore not responsible.

The judgement helps to confirm the jurisdiction of the French courts where incidents happen in international waters, and which ultimately covers wet leased aircraft registered outside of France, but operating a French airline service.

None of this is directly related to AF447, though it does confirm the jurisdiction the French courts have over this accident.

roulishollandais

27th Sep 2012, 13:27

Thank you mm43.

International private criminal law :
It is important to have in sight that international cases concerning private actors are judged by national Courts with national laws.The first difficulty is to know if some Court has the competence to judge. The second is to know wich national law must be applied on the case and for the different actors. The third great difficulty is to get effective execution of the decision in another country.
The concept of "Jurisprudence" has generaly no interest, as international cases are very specific. But they are uses who have been established, and who are respected in any country in the world "democratic" or not, "capitalist" or "communist". That does International Law is a reality.
Force of "res judicata" ("force de la chose jugée" in French) does that a country will not judge a second time the same case.
Damage have to be repared : it is an old global law of the trade to be trustful.
Very often the law which is used is not always the law of the state of the Court.
No mention to sworn translators, and lawyers who have to travel from continent to continent..., and the high cost...
The case may be shared in different parts in different countries if special international treaties allow that, like ICAO, IATA conventions, aso.

The intention of Me Soulez-Lariviere concerning the Erika/Total case, and Aviation crashes :
It has been well explained by Me Soulez-Larivière (defending FRANTZEN the Civil Aviation Director), and also some Air France and Airbus lawyers in the Ste-Odile A320 Air Inter Crash (20.jan 1992) I could listen them as I was present at the both trials. Aeronautical crossover Atlantic lobbye hope to change the law,to avoid possibility of criminal charge in the air disasters... As Soulez-Larivière asked it to the Cassation Court. He tried and failed ! Why did he try that?
Remember that Soulez-Larivière became a star lawyer in France since he was the defender of the two DGSE agents who put a bomb on the Greenpeace ship in the Auckland Port. He obtained the false couple Turenge to plaid guilty, and France had to pay some billions to New-Zealand help state secret negociations (and french people have to eat a lot of muttons, and tons of kiwis !). After a time in New-Zealand jails, Mafart and Prieur could fly away toward HAO island for some years. That french typical conspiration story killed a men and destroyed the ship in the Port. It has been said later from well informed sources, that the DGSE's teams had been betrayed by others... Someones said Mafart would not have to phone to a DGSE number. But that helped to consider Prieur as a french agent aswell they officialy had no women... Soulez-Larivière got the benefit to be considered as a specialist of international difficult cases. But that was a Public International Law case...

roulishollandais

27th Sep 2012, 15:48

That would be the EASA...
BEA did say that ,with some recomandations done to EASA.

BEA added the FAA, as they have seen the EASA certification was depending on FAA certification.

But did the latter depend on Vietname's once by a french DGAC agent as it was the case for A320 systems?

Court will have hard work.

mm43

27th Sep 2012, 20:46

It is worthwhile pointing out that establishing jurisdiction is essential to France, as France won't necessarily be bound by a judgement of the International Court of Justice.

This was the very reason in the "Rainbow Warrior" case (roulishollandis mentioned), of international terrorism committed by agents of the French state in New Zealand, that NZ sought the mediation of the UN Secretary General, and to which France ultimately agreed to the terms negotiated. There was a technical breach of those terms when the two DGSE agents (under house arrest on Hao Island for 3 years) were repatriated to France a year earlier than agreed due to claimed "ill health".

At the end of the day, all law is the result of political action, and the application of International Law is often open to political rejection when an affected state feels offended.

jcjeant

27th Sep 2012, 23:20

Hi,

Do not forget the last and extreme resort that is the international justice court of human rights based in Strasbourg
When it is entered and the case is admissible .. it can make (if any) notice very opposite even to that of a supreme court of any country

roulishollandais

28th Sep 2012, 16:44

-@jcjeant
To go to CEDH (Strasbourg-F) allows Total to get time. But CEDH will never say they had no right to "equitable" justice, which is the only thing they could try to plaid
@mm43
CIJ is the Court for public international law, which is not the case for TOTAL/ERIKA nor AF447 who are concerned with private international law.
Negociated solutions are possible between States in public international law despite criminal cases. So was the Rainbow Warrior case in the second part.
But in french law in national or private international criminal case it is not possible.
(You are right mm43 , France was not loyal with the health problems!!, and was really unloyal with New-Zealand with state terrorism, aswell as international law and relations conception).

It is time that law gets respected everywhere in France to improve air safety. As a french pilot i discovered that since 1980.:E

CONF iture

29th Sep 2012, 00:24

Consider the pilot knows what's best and demands NU on SS, hence the Elevators follow and as the airspeed is bled off and the 'g' commanded is not being met, the THS commences its journey. It knows no better, only that the pilot knows best.
But the logic is biased here as in Normal Law the pilot can keep pulling on the stick and still the THS will stop moving further up as speed reaches alpha prot. The system does not permit the pilot to know better, but on known sick data, the system is allowing the pilot to know better by "assisting" him when actually it should simply retract as it did by commanding AP A/THR and FD to withdraw.
The point of all this is that if the aircraft during this UAS event had actually gone into Direct Law, and the THS was limited at 3° NU, the aircraft when handled the way it was would still have stalled. Owain Glyndwr has pointed out many times that the Elevators [alone] were quite capable of providing whatever NU/ND was requested.
Of course it would have stalled, but never to that extent, and with much better chance to get an exit point.
Give a reason why it would be indicated to trim further up approaching the stall or already in it ?

The advantages of Direct Law were significant (http://www.pprune.org/7378242-post109.html).
Sophistication helped to set the trap.

CONF iture

29th Sep 2012, 00:26

Thirty-plus crews handled this event without incident; one did not. Where is the basis for fundamental autoflight or system design changes in this?
There is no need of fundamental autoflight or system design changes, there is a need of transparency or how to call a cat a cat.
The THS behavior and influence in this accident must be detailed, not hidden.
On the sidestick concept, it is a very first time the BEA is commenting, but still, the comment seriously lacks of character.

DozyWannabe

29th Sep 2012, 00:39

But the logic is biased here as in Normal Law the pilot can keep pulling on the stick and still the THS will stop moving further up as speed reaches alpha prot.

Which is why pilots are trained on the differences between Normal Law and the others.

The system does not permit the pilot to know better

Actually the system is deferring to the human pilot because it knows that it does not have the information to make that call.

when actually it should simply retract

In your opinion.

as it did by commanding AP A/THR and FD to withdraw.

I know you feel differently, but the fact is that in almost every respect Autotrim is not automation in the same sense as AP and A/THR - it is simply a dumb load-balancing device and does not require the inputs that AP, A/THR and FD do.

Of course it would have stalled, but never to that extent, and with much better chance to get an exit point.

Again, that's your opinion. The fact is that the difference related to a matter of seconds, and that proper corrective action on the sidestick would have caused the autotrim to *assist* in recovery if necessary.

Give a reason why it would be indicated to trim further up approaching the stall or already in it ?

The flight control system does not understand "stall" as a concept - we've been through this.

The advantages of Direct Law were significant (http://www.pprune.org/7378242-post109.html).
Sophistication helped to set the trap.

Again - in your opinion.

The THS behavior and influence in this accident must be detailed, not hidden.

The THS behaviour *is* precisely detailed in the report. The "influence in this accident" is not proven and simply conjecture on your part.

On the sidestick concept, it is a very first time the BEA is commenting, but still, the comment seriously lacks of character.

How so?

Machinbird

29th Sep 2012, 02:56

I know you feel differently, but the fact is that in almost every respect Autotrim is not automation in the same sense as AP and A/THR - it is simply a dumb load-balancing device and does not require the inputs that AP, A/THR and FD do.Dozy,
I know it has been a long time since you have flown, but did you ever learn how to trim up an aircraft?

You seem to not appreciate the significance of trim in aircraft control, particularly, speed control. In the old days, before everything became automated, that was the foundation for getting an aircraft to behave. It is also one of the skills that can deteriorate with disuse.

DozyWannabe

29th Sep 2012, 03:08

Not to put too fine a point on it, but this isn't the old days.

Because the flight surfaces do not have force feedback to the PFCs in the Airbus design, trimming the aircraft by feel is not possible in the same way as older designs. This is the main reason why autotrim was developed.

Clandestino pointed out a while back that it can be done visually, but I suspect that you wouldn't want to be doing it all the time.

Machinbird

29th Sep 2012, 03:58

Because the flight surfaces do not have force feedback to the PFCs in the Airbus design, trimming the aircraft by feel is not possible in the same way as older designs. This is the main reason why autotrim was developed.Dozy,
There is more to the art of trimming than you indicate. It is a two step process. First, get the trim into the ball park (An airbus that hands itself to you should already be in rough trim).

The second step is to make small adjustments to get the final aircraft performance desired (that is the perishable skill part). In the F-4, C-1, A-4, or F-9, it was done with quick clicks on a "Coolie Hat" switch. At that point, you are not so much getting rid of force on the controls as getting an aircraft parameter such as roll rate, rate of climb, or airspeed stabilized. In an aircraft with a trim wheel, it involves small inputs to get the aircraft to fly hands free. You let go of the stick to make the final corrections.

I'll bet that works well in the 'Bus in Direct Law. You would just have to remember what control to use for trimming roll (Rudder trim).

jcjeant

29th Sep 2012, 05:03

Which is why pilots are trained on the differences between Normal Law and the others.Can be .. but
All men learn in one of three ways:
1. Some learn by being told.
2. Some learn by being shown.
3. Then there are those that learn by experience. They just have to urinate on the electric fence
I think that the men of the AF447 are those of the option N°3 .. but unfortunately they can't anymore use the experience (if any) acquired

DW
The flight control system does not understand "stall" as a concept - we've been through this.That's interesting
Not understanding "stall' is for a "flight control system" a serious mistake
What do you think of a pilot (the human flight control system) who does not understand the concept of "stall" ?
What do you think of the designers of a "flight control system" who do not understand the stall as a concept ?

CONF iture

29th Sep 2012, 14:37

In your opinion.
Again - in your opinion.
... and simply conjecture on your part.
In my opinion ... correct Dozy.
The opinion of someone flying ... for some time now and on the thing.

gums

29th Sep 2012, 15:43

Sorry, Doze, but I gotta go with the 'bird on this one.

Unless the new pilot learns in a FBW system that trims to relieve pressure on the stick for an AoA, then some of we dinosaurs have a point.

The 'bus does not seem to care what the AoA is until reaching some of the AoA "protections". It simply reduces pressure on the stick so's the pilot can gradually release pressure/displacement to achieve one steeenkeeng gee!( sorry, but my time was pressure and our stick only moved an eighth of an inch). You can't trim for an AoA using the 'bus FBW system in Normal or a few reversion modes. The jet is basically speed/AoA neutral in most cases. Our primitive system allowed us to trim for a gee unless gear was down, then it was biased to achieve some semblance of speed/AoA stability. A natural feel with gear down, but not as crisp as most of us were used to or wanted. The system basically lied to the gee command function using our AoA probes.

My point, and that of others, is that this mechanization is not "natural" for many. Our cadre quickly found this out when gear up, but we were yanking and banking a lot and it didn't matter.

That's my story, and I am stickin' to it.

DozyWannabe

29th Sep 2012, 17:36

My point, and that of others, is that this mechanization is not "natural" for many.

That's fine and I have no problem with that - however my point is that the traditional control methods and flight deck layout grew out of the limitations of the technology of the day. As technology improved, some of the more awkward aspects were implemented in a different way. So while it may not feel "natural" for some, for others it's fine.

I'm prepared to bet that in another 20 years, there'll be enough incremental changes for those who at this point in time find the A320 perfectly natural, to feel a little uncomfortable - it's in the nature of the beast called progress.

Not to mention human psychology when confronted with change.

Lyman

29th Sep 2012, 18:35

The behaviour, (I assume you mean the position of the THS), is not hidden from the crew, it's movement is plainly available on the pedestal via the movement of the THS wheel, the illuminated position indicator, and the Flight Control Page. .....PJ2

I find the oblivion on the part of the pilots re STALLWARN somewhat acceptable, given the nature of the situation. What is inexplicable is the position of the THS throughout, post STALL. Not a sausage. Not a word.... The Captain says "Eh, what the Hell are you doing?" upon his cockpit entry, then says essentially nothing until impact, save for comments that amount mostly to "tweaking" the airframe, whilst descending at 180 mph, in a NOSE UP attitude?

Not a word. "LOOK at the gd TRIM, rook, its maxed!!" Nope, although later he says essentially, "maybe the a/p is selected on?"

In the descent to impact, the angle of incidence is set to its maximum, (13+ degrees), and the captain says nothing? Incidence, in this case, used to describe the angle of the THS from its longitudinal neutral... And its effects on the AoA of the airframe....(wings)

How stubbornly fixed on an "explanation" of "N/A" ("not aware") do people have to be? If a drama for a screenplay, NO ONE would accept it as possible.

And that's the best offer of conclusion?

Fine. However, to do so, one needs to roundly condemn the package, not the crew alone.

DozyWannabe

29th Sep 2012, 19:15

Information presented to the Captain on arrival consisted of problems with:

Speed indication
Lateral instability
Pitch instability (to a lesser extent)

The Captain arrives at 02:11:42.5 - in many ways the worst possible time for diagnosis. At this point the stall has developed and the nose has begun to drop sharply - he was never aware that the aircraft had been held nose-high for over 30 seconds prior to his arrival.

As such he was mis-cued by the information presented and, as a methodical professional, tried to solve the problems he was aware of as they presented. He was missing a vital piece of information from the start of the sequence and had no reason to look at trim initially. By the time the PF makes his admission of pulling up for some time it's too late, and shortly thereafter the GPWS was taking all their attention.

Lyman

29th Sep 2012, 19:30

Dozy

All three of the above bullets were screaming for the Captain to check attitude, and screw the rest.

Have you an inkling for the environmental cues available to Captain DuBois?

He had just climbed a deck that was quite steep, heard the Stallwarn, and came to find a baffled aircrew. You think he assumed the imstruments had been ignored prior to his entry?

the pilots reported they were clueless, would you not first check attitude?

The nose then dropped through twentyfive degrees, you would fix on AS?

Give these crew just a little assumed credibility....

CONF iture

29th Sep 2012, 19:38

By the time the PF makes his admission of pulling up for some time it's too late
And the captain could not tell the PF was pulling up before he made that own admission … What a nice concept Airbus really.

DozyWannabe

29th Sep 2012, 19:55

@Lyman - I'm not assuming anything. While the cues as a whole may suggest checking attitude, in the event they were presented sequentially - it's obvious with 20/20 hindsight, not so obvious in the heat of the moment.

@CONF iture - Theoretically yes, but based on the historical evidence, whenever a yoke-equipped aircraft has been stalled due to UAS and the PF continues to haul back, none of the other flight crew have either noticed or commented on it. In fact the PNF knew full well that his colleague had been pulling back earlier in the sequence, but - for whatever reason - never mentions this to the Captain.

jcjeant

29th Sep 2012, 20:32

Information presented to the Captain on arrival consisted of problems with:

Speed indication
Lateral instability
Pitch instability (to a lesser extent)

And certainly one more ... the trim wheels position
That's a important item for the control of a aircraft
But seems the captain forget this important item in his "screening" of instruments
If he was not able to see clearly the position of the Bonin (or Robert) stick (for some reasons) .. at least in the position he occupied in the cockpit .. the captain had full view on the trim wheels .....
There is none so blind as those who will not see

gums

29th Sep 2012, 20:47

I would pray that future pilots, and even some of the "monitors" of today, would understand what makes planes fly.

I do not buy into the "technology will make things feel 'natural'" argument unless we have pure "monitors" and Nintendo crews that are clueless when sierra happens. Otherwise, why have crews at all? Trust the technology and let HAL talk to the SLF's and maybe have one or two human flight attendants. Is that what we are looking at?

The "monitors" must understand what makes planes fly. AoA versus lift, change in speed at the same AoA versus lift, thrust versus drag, overspeed symptoms, stall symptoms, flight control laws that disguise the natural aerodynamic characteristics of the jet, flight control reversion laws, appropriate control inputs when sierra happens and HAL syas, "Dave..... you got it!"

Our system had the same trim implementation as the 'bus except we could trim for any gee from plus 3.5 to about minus 1.5 or so. We mostly trimmed for one gee, and we had the "auto trim" just like the 'bus. However, we were much more advanced when pulling or pushing due to the AoA inputs. e.g. you could pull all you wanted, but eventually you got to one gee and max AoA. In between, you rode the curve of AoA versus gee - pick an AoA and gee changed with speed, or pick a gee and AoA would change with speed. Duhhhh. Gear down and you trimmed for AoA, same as Orville did when he taught me to fly.

Back when the Earth was still cooling, we tried pitch rate laws, pure AoA laws, and finally got to a pitch rate/roll rate/ AoA/ gee control law, all mixed together to get the jet to do what you wanted and it wanted. Worked for me, and still does almost 40 years later. Why is that?

DozyWannabe

29th Sep 2012, 21:59

But seems the captain forget this important item in his "screening" of instruments

I wasn't referring to what he could see, I was referring to what he was told (and what he wasn't, namely that the aircraft had been nose up and climbing for over 30s prior to his arrival).

When problem-solving, the first thing you do is gather information from those already present and focus on those issues. This is because in most cases it's quicker to get a summary from them rather than try to work it out from scratch yourself.

I do not buy into the "technology will make things feel 'natural'" argument unless we have pure "monitors" and Nintendo crews that are clueless when sierra happens

That's not what I said - I said that what is perceived as "natural" is bound to change over time.

Think about it. Cable controls, electro-mechanical devices, hydraulics - they're all "technology", and they ended up feeling natural. Why not this setup?

gums

29th Sep 2012, 22:46

A good point from Doze:

Think about it. Cable controls, electro-mechanical devices, hydraulics - they're all "technology", and they ended up feeling natural. Why not this setup?

Trust me, Doze, I learned in planes that were basically 1930's technology. You prolly did as well, as many of us here. I was never one to resist the advances in technology that went to irreversible hydraulic controls, yaw/pitch dampers, etc. That being said, I was taught the basics of how planes fly and what to do when things went south.

In the 70's a new system came along designed purely for enhanced performance made possible by FBW. Talk to any other Viper pilot and we all had the same concerns, but they were about the control system reliance upon electrons to do the same thing that we had done for 30 years with irreversible hydraulic controls. We also balked at the limiters ( "protections" for the 'bus). We adapted. But we still understood the good, bad and ugly. We still understood the basic aero, and we were prepared when sierra happened.

We all worried about the Atari generation coming to us in 1980 ( Nintendo and Xbox were not on the scene then). So we explained in excruciating detail how the plane used basic aero to zoom about, and how the flight control laws helped to keep them flying at optimum performance. Then we demonstrated it for real. We had no problems, and many of the young nuggets went to Eagles later and had no problems with a conventional system.

I don't see that with some of the current crop of folks in the commercial planes, and it scares me.

There has to be some basic philosophy about flying jets that is ingrained in the pilots/crew that seems to be fading.

DozyWannabe

29th Sep 2012, 23:07

I don't see that with some of the current crop of folks in the commercial planes, and it scares me.

There has to be some basic philosophy about flying jets that is ingrained in the pilots/crew that seems to be fading.

To be fair, I suspect the generation who grew up flying Trimotors and DH Rapides probably felt that way about the crop of pilots who cut their teeth on the Sperry-era autopilots! ;)

If you look at the thread in R&N, you'll see that Airbus are completely reworking their training syllabus for the A350 onwards, starting with handflying skills and building up from there. I think it's a good start.

CONF iture

29th Sep 2012, 23:51

In fact the PNF knew full well that his colleague had been pulling back earlier in the sequence, but - for whatever reason - never mentions this to the Captain.
The PNF did not know, as most he could guess, nothing more.
The CPT had no idea before the PF comment, due to the Airbus concept.

Theoretically yes, but based on the historical evidence, whenever a yoke-equipped aircraft has been stalled due to UAS and the PF continues to haul back, none of the other flight crew have either noticed or commented on it.
False – Either the PNF was ok to pull more, either he did not have the confidence to challenge the PF. In all cases he was perfectly aware of the inputs made by the PF : Priceless !

DozyWannabe

30th Sep 2012, 00:08

The PNF did not know, as most he could guess, nothing more.

He knew because he saw what was happening on the ADI ("You're going up, so go down.")

The CPT had no idea before the PF comment, due to the Airbus concept.

And because no-one told him the aircraft had been nose-up and climbing for 30s prior to his arrival.

False – Either the PNF was ok to pull more, either he did not have the confidence to challenge the PF. In all cases he was perfectly aware of the inputs made by the PF!

Certainly in the Birgenair case there's not enough information to tell one way or the other. All we know is that at no point did the PNF ask the PF why he was pulling up, or try to take the controls. Like the trim wheel in front of the AF447 Captain, it doesn't matter if the information's there if it isn't seen, heard or felt.

Look - I don't want to keep arguing over this - you have your viewpoint, I have mine, can we call it quits?

CONF iture

30th Sep 2012, 00:45

He knew because he saw what was happening on the ADI ("You're going up, so go down.")
You could go up for many reasons and still pushing on the flight controls.
If I follow your logic, when AF447 was 10 degrees ND and going down it was necessarily because the PF was pushing his sidestick ... was it the case ?

Quit at your own convenience.

Linktrained

30th Sep 2012, 01:07

Dozy #536
As a Rapide Captain ( nowhere for a F/O to sit !) I had to "sign-out" the 1179 form that my Chief Pilot ( who was also my employer) was "fit to fly in command."
A/Ps on later types of aircraft were not always able to be used. 1500ft was the minimum for A/P for the B170, where the cruising level outbound to Le Touquet was 1000ft with return flights at 1500ft. (Up to 12 sectors per day.)
This allowed plenty of practice for both pilots.
Some later types had only single channel instrument landing capabilities - and a number of airfields still lacked ILS but might have an impressive Terminal Building instead. ( Which would you prefer to show to the President of your country?)

jcjeant

30th Sep 2012, 01:07

I wasn't referring to what he could see, I was referring to what he was told (and what he wasn't, namely that the aircraft had been nose up and climbing for over 30s prior to his arrival).

When problem-solving, the first thing you do is gather information from those already present and focus on those issues. This is because in most cases it's quicker to get a summary from them rather than try to work it out from scratch yourself.That's the biggest mistake you can make when you are the responsible...
Take advices of others is one thing .. rely on those and do not make your own job is another thing !
You can not explain (justify) a mistake on your part by an error of your subordinates
At the end .. it's you the responsible .. and you are paid for this !
In any case this is how it worked in my profession
BTW .. the informations gathered by the captain were:
We don't know .. we don't understand .. we have try all .. we don't control anymore the plane
That's very useful information !
So the focus of the captain (make your job) was to take the controls from those two lost people
Instead he stay seated between the two ... and as a viewer it looked this bad movie unfolding before him

Linktrained

30th Sep 2012, 12:06

The Captain ( and the other two pilots) may well have seen that the THS was moving, as it does, usually and quite normally, untouched by human hand, but may not have noticed that the direction was (largely?) NU. A quick scan in the current circumstances could have failed to note the actual readings.

( My very ordinary car's oil pressure is indicated on a gauge, which I seldom watch. If the reading becomes abnormal I am alerted by a warning light so that I can take the appropriate action, pull over to a safe place.)

A modern aircraft like .......... should have something similar, when the THS goes to something out of its normal range, whatever that should be. (I might prefer a pulsing rather than a flashing light, adjacent to the THS.)

DozyWannabe

30th Sep 2012, 15:17

The Captain ( and the other two pilots) may well have seen that the THS was moving, as it does, usually and quite normally, untouched by human hand, but may not have noticed that the direction was (largely?) NU.

In fact the THS was almost fully-NU by the time the Captain arrived, and as such the abnormality would have been that the trim *wasn't* moving much despite the fact that their pitch was all over the place.

Linktrained

30th Sep 2012, 17:18

Dozy,
Just how much of the range that is possible of NU on the THS would be used in a normal cruising flight at altitude ?
You have flown the sim ( with any limitations that may or may not have had). Your recent experience exceeds mine by several decades. (Earlier aircraft types used to cruise with the trim close to the middle, more than a notch or two, up or down would be uncommon.)
"Almost fully NU..." would have made "my oil pressure warning light / excess THS" illuminate, (had it been fitted).
Perhaps this would still have been too late for the Captain. But there were two other pilots...

The CVR print-out can give no indication of just how "10,000 ft." was said, as the first mention of direction of travel.

BOAC

30th Sep 2012, 17:27

The concept of 'limiting' normal THS movement was proposed after the PGF crash, but seemed to go nowhere. I mooted a 'push to over-ride' button set at an appropriate value.

CONF iture

1st Oct 2012, 00:37

I assume you mean the position of the THS
The information display on the position of the THS is not my point of contention, the information on the THS functioning depending on the laws, sub-laws, or sub-sub-laws, is.
Except from the FDR data, the BEA report is absolutely empty on the matter.
To be told that the THS moved from 3 to 13 degrees in 1 minute or that the THS moved accordingly to the stick inputs and as designed is vastly insufficient.

The "influence of the THS" argument has been demonstrated as a non-starter.
Far from it.
Owain Glyndwr made very interesting comments (http://www.pprune.org/6663753-post457.html) which should have been already part of a final report. The BEA had all the necessary tools to elaborate further on the subject.

3 degrees versus 13 ?
No autotrim versus autotrim ?
Direct Law versus Altn36Z ?

Owain Glyndwr comments are necessary and welcome. They deserve further analysis but are certainly not already the conclusion to avoid looking in that direction.

Why not trimming in a stall ?
You’ve been asked the question (http://www.pprune.org/7338268-post951.html).
You did not reply ... ?

airtren

1st Oct 2012, 02:14

What does it take to get out of hibernation?

CONF iture;

The "influence of the THS" argument has been demonstrated as a non-starter. The aerodynamic argument has been examined by Owain Glyndwr to which reference has been made before.

For lack of better words, it seems this is pushed quite a bit far out of context.

The aircraft remained in the stall because of the predominantly NU stick position held in by the PF, and not due to the position of the THS.
I have great respect for the mastering of a careful and well thought out writing in posts carrying your signature, and the surprise to see an exception has certainly been a wake up.. .

You're not saying that the HS has no contribution to the NU are you? But it reads that way.

The A/C remained in stall because of the sum of the effects of ALL the aerodynamic contributing factors to a prolonged NU, of which HS is part of. The NU stick drove the automatic move of the HS to MAX NU. If the NU stick would have had no effect on the THS - if the HS would stop moving at STALL condition detection - that would have removed the HS from the contributor factors. But that was not the case.

CONF iture is absolutely right that this should be documented well by any analysis, or technical report.

mm43

1st Oct 2012, 03:04

Except from the FDR data, the BEA report is absolutely empty on the matter.
To be told that the THS moved from 3 to 13 degrees in 1 minute or that the THS moved accordingly to the stick inputs and as designed is vastly insufficientI am well aware I haven't answered your original query from my "It [the THS] knows no better, the pilot knows best" post, but I didn't really need to get caught up with that "bloody bird" circling again!

To answer your question, though rather obliquely, I defer to another part of the same post where I pointed out that Airbus expected its aircraft to be flown by properly trained and competent pilots.

I know this doesn't make anything right, but part of being a competent pilot is to have a thorough knowledge of the aircraft flight control substructure, which includes the level of automation available from Normal Law to the fallback positions, i.e. Alternate + colors and Direct Law. Likewise, I am well aware that the attributes of the aircraft when in Normal Law have been espoused ad infinitum, but that's the "gilding on the Lilly", and as you know there are "man traps" for the unwary when the automation level degrades, and AF447 clearly revealed those traps, i.e. the Stall Warning NCD switch off, and to a lesser extent the Auto Trim action when in Alternate 2B Law.

The FC training for the A350 will be different, and starting on the ground floor will IMHO enhance the basic understanding of the aircraft flight control structures, and maybe pilots will once more get to respect and understand the advantages and limitations of each layer of automation that gets added.

You claim that the crew of AF447 were badly served, but I venture that poor CRM along with some unfathomable actions by the PF provided none of the service expected by the aircraft, nor the other souls onboard that night.

I respect your right as an A330 pilot to question the data and confusing manner in which the crew became aware [or in this case not aware] of their situation. Though, I'm inclined to ask why the situation that developed at A/P off wasn't resolved as UAS by them? They knew:-

Entering the ITCZ,
OAT higher than expected,
Had started Anti Icing on engines,
Characteristic 400 foot Altimeter drop when Pitot/Static system suffered short-term icing,
Lost Airspeeds,
ECAM - ALT LAW (Prot lost).

The only cue they didn't get, was a reminder that they should refer to the QRH, but IMHO that comes under the second paragraph of this post.

gums

1st Oct 2012, 22:08

Thank you mm43 and PJ2.

I shall sit back for a while, as well, but noted the recent article about training for the A350 or whatever the thing is called. Emphasis upon flying the basic FBW system, then adding all the neat A/P functions and normal law "protections".

bubbers44

2nd Oct 2012, 01:32

Airbus made a good change in their initial training with the manual flying prior to blending in automation. Hopefully that won't be the end of it because we all know if you don't practice it on a regular basis the skills gradually deteriorate.

SOP's allowing pilots to handfly when conditions are right is the only way they can maintain those skills.

It is in everybody's best interest to let them retain these skills.

gums

2nd Oct 2012, 14:43

from PJ2:

....It was "normal" after a while and flying a raw-data, no FDs, manual thrust ILS even in clear weather slowly became a real challenge.

That, quite frankly, is not and never was, a good thing. Autoflight's a simple bread-and-butter assistant, not one's keeper.

Guess we're from the same "mold", PJ.

As I have oft-stated, I encouraged the fighter jocks I flew with/helped learn to use the A/P to reduce workload when things got very BZ. With only one human in the jet, the A/P really helped during a WX abort/diversion to new field or an alternate approach. The big difference between our use of the A/P was that it was the exception and not the rule. Sure, we used altitude hold and heading hold when crossing the pond or flying st-and-level for more than 10 or 15 minutes. But we never used it from 500 feet AGL after takeoff until final approach. Seems to me that with a crew of two or more that "the other guy" can handle the admin and the pilot can simply fly the profile best he/she can.

I have a hard time understanding why the human pilot cannot descend/turn/climb within a few knots or a degree or two heading/pitch. My only experience in a "heavy" was a joyride in the 'vaark. Sucker weighed 3 times what my Viper did. That being said, I flew a st-in and landed the sucker all by myself after about 20 minutes of "stick time". Once getting it lined up and trimmed, holding within 2 knots and a half degree of required pitch for the descent was a straightforward exercise. It was like on a wire. Very comfortable. And my B747 captain buddy said the same thing about that beast.

And be advised that in the T-33 with the J-8 attitude indicator that we made pitch corrections for a GCA or ILS approach using the thin white line on the "horizon" line - figure about a half degree of pitch or less. The SLUF had a "flight director" to cue you when intercepting the ILS glide path and centerline. The Viper was pure manual, and you can see my emergency landing HUD here to see how we did it ( Q-time required):

http://www.sluf.org/warbirds/lef-landing.m4v

For those HUD naysayers, I can guarantee that a raw nugget made beautiful approaches first time. That flight path marker didn't depend upon any air data - it was pure inertail vector, and was easy the "lead" the turn or pull.

airtren

2nd Oct 2012, 21:08

airtren, CONF iture;

Thank you for your observations and critique of my last.

airtren, re your comment, "You're not saying that the HS has no contribution to the NU are you? But it reads that way."

No, I am not saying that the THS "has no contribution" to the NU attitude.

Now that I review it, you are right that the statement, in and of itself, wasn't nuanced as I have in the past and can read that way.

Thanks for reviewing your post, and making the above clarification..

But the contribution of the THS to the sustaining of the stall has been thoroughly discussed even if it has not been thus in the BEA Final Report, and my own views on the contribution of the THS are both expressed and known as are my views on why the stall continued instead of being recovered from.
..... I made the observation that overall, the behaviour and contribution to the stall of the THS has been thoroughly examined and the statement made on such contribution thus, (bolding is in the original) by someone who really knows what they're talking about, supports the view that the NU stick and not the THS were the critical factors:
I've expressed my opinion myself at least once on the THS contribution to 1) entering and 2) staying in STALL - this thread is repetitive.

Even though you may have NO acrobatic or fighter pilot training, and thus direct and repeated experience with entering and exiting stalls, I would ask nevertheless your opinion based on your pilot expertise:

Question:
If you were the AF 447 Captain, and had understood at the very moment of re-entering the cockpit, the Stall state, and the Cause for it, the extremely short amount of time left for a successful recovery, and had known what it takes to exit the Stall and recover the A/C, what would you have ordered the PF to do?

1. move stick ND ASAP and move THS manually to NEUTRAL or MAX ND ASAP
or
2. move stick ND ASAP and keep THS to MAX NU?

DozyWannabe

2nd Oct 2012, 23:40

1. move stick ND ASAP and move THS manually to NEUTRAL or MAX ND ASAP
or
2. move stick ND ASAP and keep THS to MAX NU?

You're missing option 3:

3. Move stick ND and allow autotrim to move the THS back to neutral.

Possibly a little slower than option 1, but not by a great deal.

In fact option 2 is impossible. Pushing the stick ND will cause the THS to follow suit in Alternate Law.

airtren

3rd Oct 2012, 01:13

No, I am not missing anything!

But you're missing:

I. that both 1 and 2 involve Manual Control action onto the THS from the pilot.

II. "the extremely short amount of time left for a successful recovery" from my post.

I know you're not a pilot... A pilot will do everything in his direct power, to speed up the action on control surfaces, knowing that time is NOT on his, his crew, and his passengers side.

Although I have to thank you for making my point by answering indirectly my question by indicating option 1 as the fastest..... as a matter of courtesy, your abstaining from interfering with my question directed to PJ2, by obstructing it, or answering it, and letting PJ2 answer, would be also appreciated.

You're missing option 3:

3. Move stick ND and allow autotrim to move the THS back to neutral.

Possibly a little slower than option 1, but not by a great deal.

In fact option 2 is impossible. Pushing the stick ND will cause the THS to follow suit in Alternate Law.

CONF iture

3rd Oct 2012, 03:18

Nor have you answered my questions in my last (http://www.pprune.org/7439948-post524.html).
Do we have a kind of misunderstanding here as you're asking me to defend a position that is simply not mine - I am not looking for any kind of design change regarding the THS display and information on the flightdeck - THS wheel + indicator are just fine to me.

The THS behavior and influence in this accident must be detailed, not hidden.
I was probably not clear : By 'THS behaviour' I was asking for technical information : Why, when, how, for how long, to which limit, at which rate the THS is moving in ALT2B or whatever the law ?
Not much in the FCOM and nothing more in the BEA reports - Actually a pdf research on THS shows how unpopular those 3 lettres are to the BEA ...

the ECAM drills were not done when the event occurred
I disagree on that.
It took 35 sec (or is it 15 ?) to move the thrust levers, that's all.

CONF iture

3rd Oct 2012, 03:27

In fact option 2 is impossible. Pushing the stick ND will cause the THS to follow suit in Alternate Law.
If it was the case the THS would have reach its physical NU stop.
What did stop its operation ?

Lyman

3rd Oct 2012, 16:09

Except to say there is no evidence presented in favor of, or in disagreement with, the above, I would suggest that's essentially what happened.

The Captain's comments were initially leaked, "This is STALL, get the Nose DOWN". That was reported in the Press, and one can draw their own conclusion.

By its absence, virtually all here have concluded it did not happen. Given the fact that the Captain entered the cockpit when he did, having heard Stall, and seen the cues described above, it would be incumbent upon BEA to provide the CVR audio surrounding this entry into the flight deck. Instead, nothing....

I do not know if the CVR even exists, or if the chronology was assembled out of whole cloth. Were I family, or friend, I would make it my mission to acquire the last words, if only to be with these men in their last moments.

Given the stakes at hand, one tends to be suspicious even of saints, let alone an agency with a history that suggests scepticism might be in order....

The chronology above is hindsight, as warned, but suggests that with all the cues and conditions present, the Captain and his two F/O's were other than qualified. And that is not the case.....Something is missing, literally.

TTex600

3rd Oct 2012, 16:23

Organfreak

3rd Oct 2012, 16:30

@TTex600, with the greatest respect:
Lyman, the problem you face is simply that no one still participating in these discussions is interested in why the event occurred. Most everyone is either: defending a position, or defending a perception, or pontificating to hear themselves talk.

By now it is obvious that something IS missing, what that is may never come out. Que Sera Sera

As it happens, I agree, for once, with Lyman on this point, and am still interested in what may be missing, not that we'll ever find out! :confused:

Was this so-called leak accurate? Inquiring minds will never stop inquiring.

Lyman

3rd Oct 2012, 16:34

TTex600

3rd Oct 2012, 16:38

@TTex600, with the greatest respect:
Quote:
Lyman, the problem you face is simply that no one still participating in these discussions is interested in why the event occurred. Most everyone is either: defending a position, or defending a perception, or pontificating to hear themselves talk.

By now it is obvious that something IS missing, what that is may never come out. Que Sera Sera
As it happens, I agree, for once, with Lyman on this point, and am still interested in what may be missing, not that we'll ever find out!

Was this so-called leak accurate? Inquiring minds will never stop inquiring.

Which is why I qualified with "most". I'm just tired of the spin coming from "most". It seems that "most" are missing the forest and focusing on individual pine needles. I guess it's time to go back to union infighting and name calling on US boards.:(

Lyman

3rd Oct 2012, 17:19

"The transcribed CVR indicates that standard ECAM discipline was not accomplished. Without announcement or communication to the PNF, a sustained pitch-up occurred, even as the PNF attempted to do the ECAM drills. There was no announcement of the ECAM messages from the PF, and their subsequent response was done in an undisciplined, halting manner that did not initiate and did not complete as per SOPs*. There was no evidence of CRM."

You are missing the evidence to support your conclusion. The CVR is not complete, we do not know what is missing....

Speculation, over time, morphs into gospel...

As expected, BEA succeeds.

DozyWannabe

3rd Oct 2012, 17:26

Dozy;

It is courteous and respectful to permit the person addressed in a communication to respond first. Thank you.

Apologies for the presumption - I only did so because I know you only check in here rarely these days. Won't happen again.

The Captain's comments were initially leaked, "This is STALL, get the Nose DOWN". That was reported in the Press, and one can draw their own conclusion.

Quite - this is the same press that is regularly pilloried in these forums for not knowing the difference between elevators, ailerons and flaps (and tending to use the term "wing flaps" for all three), having no apparent grasp of piloting or procedure and turning every incident into a "terrifying plunge" which narrowly avoided schools and hospitals. The same press that to all intents and purposes punished Captain Burkill of BA038 for refusing interviews by publishing scuttlebutt - almost destroying his career in the process. The same press that frequently quotes out of context to create controversy.

I'm not saying that there haven't been occasions where press action has brought things to light in a positive way (I'm thinking particularly of the expose on the MD/FAA "Gentlemens' Agreement" regarding the DC-10 cargo door, and the Seattle PI's dogged pursuit of the 737 rudder problems), but on balance I'd say I'm inclined to take isolated press reports with a hefty dose of salt.

Lyman

3rd Oct 2012, 17:33

As am I, my friend. But to broad brush the media, in this case, puts BEA on a Pedestal....

Ordinarily, your case would be persuasive, but BEA leave the entire product in doubt, imo.

TTex600

3rd Oct 2012, 17:50

Tex

Of course. I have no real position re: what, where, why.... From the outset, I have faulted BEA for not providing the evidence they supposedly possess; their data is based on something not in the record.

Instead of looking at that, most people do dig in, I hope I am not one, for as above, I do not KNOW.

The report is unacceptable.

1. In reporting some of the CVR, BEA leave open the suspicion that Airbus is at fault.

2. The suspicion exists also that the pilots are at fault.

3. The "Conclusion" (one of) exists that there is a blend of responsibility for this tragedy.

Without a jaundiced eye, BEA escape their responsibility, and play the politician.

Que sera? Strange attitude from a line pilot...

The only hope of getting to the evidence is to hope that the CVR still exists, or certifiable transcripts...

This can be done via FOIA if/when the FAA get access to the record...

Til then, my hope is that people do not give up, NO MATTER THE INTENT.

I don't expect the info to ever come out. Therefore, Que Sera Sera. I feel that I now know enough to deal with the "it flies like any other airplane" airplane when it quits flying like any other airplane. That's all I wanted to know when I started looking for info.

Whatever will be with the investigation, or with the PPrune discussion, will be.

xxxx will still pretend to be unbiased. xxxx will still pretend to be the best pilot ever. xxx will still pretend that it will never happen again because it happened once to AF447. etc, etc, etc, but we don't seem to be adding to the body of knowledge. In the mean time, Airbus birds will fly and I'm content with my ability to fly mine. Whatever else happens, so be it.

DozyWannabe

3rd Oct 2012, 17:56

Ordinarily, your case would be persuasive, but BEA leave the entire product in doubt, imo.

How? By not printing a remark from the crew that was once alleged by the press and therefore may not have been accurate?

Look - if we combine the more colourful language used in the book with the CVR transcript in the report, I think it's fair to say you've got probably 98% of the total CVR content in the two, and if you use the book to determine language that the BEA omitted it quickly becomes apparent that only non-pertinent language was omitted (as the report itself makes clear).

Organfreak

3rd Oct 2012, 18:24

@DW:
...and if you use the book to determine language that the BEA omitted it quickly becomes apparent that only non-pertinent language was omitted (as the report itself makes clear).

Sigh. How is "We are in STALL" non-pertinent??? I shouldn't have to point out to a smart fellow like you that what is pertinent, or not, is a subjective matter that has been decided in a closed room.

:ugh:

DozyWannabe

3rd Oct 2012, 18:52

@Organfreak - The point I'm making is that there's a good chance those words were never said, given the origin of the claim.

Also given that the transcripts we do have show no cognizance on the part of the Captain that they were stalled at any point - not just in the BEA report, but also in the controversially- published book on the subject. How likely is it that the captain would enter, immediately diagnose stall and appear to forget that he'd diagnosed a stall for the remainder of the sequence?

mm43

3rd Oct 2012, 21:00

If it was the case the THS would have reach its physical NU stop.
What did stop its operation ?I seem to remember that you have already conceded that A33Zab's proposal (http://www.pprune.org/tech-log/454653-af-447-thread-no-4-a-post6543802.html) that the PRIMs prevented any further NU of the THS after the ADRs returned NCD at around 02:11:50 [or while they returned NCD].

If that was correct, the alternative may also apply to SS ND in the same circumstances, whereby the THS may not follow the ND demand until the PRIMs allowed it. In that case, the use of the Manual Trim Wheel would be needed to resolve the situation quickly.

This situation was apparently not foreseen, and the clarification you are seeking would be welcome.

Lyman

3rd Oct 2012, 21:02

At long last....

"Also given that the transcripts we do have show no cognizance on the part of the Captain that they were stalled at any point - not just in the BEA report, but also in the controversially- published book on the subject. How likely is it that the captain would enter, immediately diagnose stall and appear to forget that he'd diagnosed a stall for the remainder of the sequence?"

I think you are on to something......

DozyWannabe

3rd Oct 2012, 21:06

Yes, I'm on to the likelihood that the press report you refer to is incorrect.

Are you seriously suggesting that they'd rewrite the entire transcript for the Captain?

Clandestino

3rd Oct 2012, 22:49

Ladies and gentlemen, dear fellow PPRuNers.

First I'd like to remind you that "blame" and "pilot error" are not phrases included in any properly made accident report, (except in the legal notice clearly stating it is not the job of investigation board to blame anyone or anything). Fault is also seldom used and then only in mechanical or electronic sense. Accident reports only state that pilots did so-and-so and occasionally can add it was in contravention of such-and-such rule or procedure. This is what folks not very well acquainted with aviation safety, or more often with aviation at all, wrongly condense into term "pilot error", which by itself wouldn't be so wrong if it didn't always come with the notion that they who erred are the ones to blame for the calamity. Such a ignorance-based mistake usually comes from media or lately, bless internet, from anonymous fora.

Since AF447 crashed into international waters, BEA was appointed as the official investigator as the country of registration was France. In its final report, it has thoughtfully provided CVR transcript from the autopilot disengagement till AoA went over 40°, superimposed on some FDR parameters (page 60 English report, page 64 French), to make it more readable than it would be the case if one would need to constantly switch from CVR transcript to DFDR graphs in order to get exact chronology of who said and did what. NTSB style animation would be even better but I guess we have to do with what we have for the time being.

What can be seen is interesting, to say the least. CM2 has promptly arrested the roll, while unnecessarily pulling and properly announced he has controls. Next thing CVR recorded is stall warning, followed by exclamation of surprise from the CM1, next both pilots commented they have no display of speeds. To digress a bit: there was a theory put forward that they were unconcerned about sudden massive indicated speed drop but rather with characteristic protection speeds being removed from from the displays. To accept it as plausible, one has to be massively unaware of the importance of the IAS in any flying, let alone airline one. Basically: speed is life. For advanced users: while in itself it is life, we can live without it being properly measured and displayed.

So far so good, there are two pilots who promptly and correctly diagnosed the problem so what should have ensued is application of proper procedure, life goes on, no one notices except perhaps FDM, etc.

However, with the benefit of 20/20 hindsight we know that it took less than five minutes form the first sign of trouble till the aeroplane impacted the ocean.

Ten seconds after he concluded there are no good indications of speed CM1 warns CM2 to watch his speed. CM2 replies with "Okay, I'll redescend" as if he were warned of climb but he doesn't. CM1 now realizes they are climbing and only then prompts CM2 to descend. CM2 agrees but doesn't reduce the pitch enough to stop climb so busts practical ceiling. Aeroplane loses energy, stall warning goes off, CM2 attempts to pitch the aeroplane even more up so seals his and 227 other fates.

Not a reaction expected from professional pilots. Perfectly understandable if we assume ones acting so are scared mindless.

There was an occasional "we steam gauges pilots did so-and-so while these new EFIS kids on the other hand..." which usually made some sense but was more often than not garnished with a plenty of nonsense as it would compare theoretical perfect pilot of yesterday with the tragically underperforming modern crew, while the unspoken but presumed narrative would be that what was discussed were the average representatives of both species. There was many a classic cockpit crew who lost the situation awareness and ended smashed against the mountain or at the bottom of the spiral dive following disorientation as there is many a wonder-electric-jet crew that turned potential catastrophe into incident (e.g. QF32). So yes, there are still pilots flying those machines overhead us and given the number of incidents that did not end up tragic (or in newspapers or PPRuNe at all) I'd venture a guess they still outnumber mere system operators by quite a large margin. Now take this statement with a grain of salt: circumstances can catch any pilot out of his depth. Trick is to be so skilled, knowledgeable, conscientious and calm to make chance of it astronomically small.

It was mentioned there was thirty-something other incidents very similar to AF447 that ended without any damage or injury. While it can be used as a definite proof that Airbus is not lethal by design, conclusion that other crews knew what happened and what they are supposed to do is so far-fetched to be patently untrue. This is the tragic part: not every did but they did manage to avoid the traps that AF447 failed into. Many survived by doing nothing while trying to figure out what is going on and so exited the area of ice that clogs the Thales pitots in the process. There were those who pulled but they didn't ignore stall warning so pushed. There were those exposed to brief stall warning as they hit updraft. After every updraft must come a downdraft so they, wrongly but not fatally, assumed warning was false.

There was many a heated argument of how this or that automated feature should have been incorporated into Airbus to prevent the CM2 from wrecking the aeroplane. Well, Einstein once observed that the good thing about thought experiments is that they always succeed. In real life, safety devices have to be designed (and demonstrated) to acceptably cope not just with the occurrences thy are supposed to deal with but also the two failure modes: 1) failure to work when required 2) activating when not required. Number 2 is dealt with by system being overridable (stickpusher) or shutting itself down when risk increases (Airbus protections and control laws). Certification authorities assume that even the crew that has barely passed the obstacles of the type rating course has good situational awareness and will recognize failures and react to them properly. There is never an assumption that crew will get totally incapacitated for prolonged period. Pilots that get detached from reality are faced with simple choice: timely regain SA and act correctly or meet thy maker. Airbus protections (which incidentally started with A300, only got more sophisticated with introduction of FBW) can only buy a bit more time for crews to regain their wits but it was repeatedly demonstrated that you can still crash while staying away from protection parameters.

What are the chances that the pilot who gets so freaked out to forget just about all the basics of flying - pitch & power, performance ceiling, that heavy buffet and failure of the aeroplane to respond to controls is indicative of stall (since warning just got ignored) would pay attention to AoA gauge or use manual pitch trim? In real world: zilch. We can indulge in wishful thinking if we find it emotionally satisfying but it won't prevent the recurrence of AF447.

There was even mention that there is no feedback from aeroplane to pilots in Airbus as sticks are not backdriven and this is supposed to be major design flaw. Well, we have mostly abandoned the feedback fifty years ago when we made the switch from power-boosted to power-operated controls. If you fly aeroplane with hydraulically operated controls and believe what comes through yoke is feedback, I am sorry to disappoint you but you have been lied to. It is synthetic pitch feel. It is there to prevent you from overstressing the airframe. It can provide clue how far you are from the trimmed state but it is not by design or purpose and folks who are mislead to believe they can use it to tell the speed error can get bitten when things get a bit pear shaped as almost was the temporarily hapless crew of G-CPAT (http://www.tsb.gc.ca/eng/rapports-reports/aviation/2008/a08q0051/a08q0051.asp). They were so concentrated on yoke feel they at one point believed they had unreliable airspeed - despite all three indications agreeing. Good thing they maintained healthy respect towards GPWS.

ECAM complications are another red herring. No abnormal checklists, no ECAM actions, no memory items, there's nothing that has be done before positive control is established (to be nitpicky: except items that prevent loss of control such as overcoming control jam or feathering the propeller that went into ground fine, nothing similar was involved in AF447) which seemingly never was.

It was mentioned that AF447 is a proof modern pilots have insufficient manual skills and that we should practice raw data manual flight more often. While I agree with the recommendation, I don't think it can be derived from the accident we are discussing. Indeed, most common contemporary accident scenario is not involving a crew that knows what goes on and what needs to be done but lack of manual flying skills prevents it from carrying out the plan. More common is the crew who loses SA, often through some minor and trivial distraction and does exactly the wrong thing (sometimes with astounding manual dexterity) so loses control. I am afraid manual flying when everything goes right does exactly nothing to prevent such a calamity and introducing distraction during simulator won't be much helpful either as basic limitation of it is that it is still a sim, it cannot simulate the feeling that you are flying for your life. IMHO problem here is the pilot that has many an hour and many a simulator session under his belt. He goes to the sim, does the motions, passes the checkrides while secretly harbouring deep mistrust of what he has been taught as he "knows" better than some manual written by the lawyers for the aeroplane made by the pilot-haters. So one day proverbial hits the fan and that's when he realizes that he has nothing to fall back upon.

Question that remains is how to prevent AF447 from recurring. Human factors are definitively the key but methinks in that aspect, BEA report leaves a lot to be desired. While I'm no expert in psychology so I can't meaningfully comment some findings from that aspect, I do know that notion that night makes maintaining attitude in passenger jet more difficult through lack of outside horizon to be utter tosh. You can combine it with the best psychological expertize and still you won't get anything true out of it. Even worse is lack of background data for the pilots involved except the very basic information. BEA should really follow the NTSB example with its background checks. We got informed that F/O of AA587 really misunderstood AAAMP to imply that it is proper to use rudder for any disturbance, was already warned by a captain on one of his previous flights, but was unable to comprehend. NTSB told us that captain of Aloha Islandair 1712 regularly scud-ran, he made wrong estimate of his position only once and that was enough. As for AF447 pilots, we have no idea whether there were precursors noted during their careers that would make their reactions more comprehensible or - far more scary option - their de-structurization and consequent disaster struck out of the blue.

DozyWannabe

3rd Oct 2012, 23:06

@Clandestino - I agree with 99% of what you are saying, however there's one point that needs to be addressed -namely that the NTSB has a further-ranging remit when it comes to identifying cause than most other agencies. Usually, civil service investigation agencies such as the AAIB and BEA are restricted to determining cause from the immediate evidence, and their write-ups consequently tend to read more drily.

CONF iture

4th Oct 2012, 02:19

I seem to remember that you have already conceded that A33Zab's proposal that the PRIMs prevented any further NU of the THS after the ADRs returned NCD at around 02:11:50 [or while they returned NCD].
Thanks for the reminder, I had forgotten that one.
Nothing was for certain in his answer but it was making sense. I didn't have and still don't have the knowledge or the tools to confirm or dispute his theory.

But for sure, such explanation should have already been part of a Final Report ... ?

Lyman

4th Oct 2012, 02:41

Quote:
Originally Posted by mm43
"I seem to remember that you have already conceded that A33Zab's proposal that the PRIMs prevented any further NU of the THS after the ADRs returned NCD at around 02:11:50 [or while they returned NCD]."

Sorry, that does not make sense to me. The reason for Alternate Law2b in the first place is duff ADRsX3. What difference does it make if they are duff or merely NCD?

Another thing, if the THS freezes with NCD ADR, why did it move at all after AL2b latched, never to be changed? If the THS did move, then the Controls Law should have reverted to Alternate Law 2, since ADR would have been reliable?

perhaps?

mm43

4th Oct 2012, 06:52

The reason for Alternate Law2b in the first place is duff ADRsX3. What difference does it make if they are duff or merely NCD? Sorry Sir, not my call.

AF447 - Thread 6, Post #962 (http://www.pprune.org/tech-log/482356-af-447-thread-no-8-a-49.html#post7214889) by A33Zab may help when working out whether NCD data had an affect on the PRIMs.

Clandestino

4th Oct 2012, 12:42

there's one point that needs to be addressed -namely that the NTSB has a further-ranging remit when it comes to identifying cause than most other agencies.Then it is cultural or political issue. After FI acquaintance of mine perished in training accident, BFU traced his former students and their testimonies about the way he performed and taught the fatal manoeuvre made it into the final report.

Turbine D

4th Oct 2012, 20:48

DozyWannabe,
In a reply to Clandestino you stated:
the NTSB has a further-ranging remit when it comes to identifying cause than most other agencies. Usually, civil service investigation agencies such as the AAIB and BEA are restricted to determining cause from the immediate evidence, and their write-ups consequently tend to read more drily.Perhaps you can explain what is meant in your quote as my interpretation would lead me not to agree. Here is the intro into how the NTSB does its investigations:
The Investigative Process at NTSB
The National Transportation Safety Board was established in 1967 to conduct independent investigations of all civil aviation accidents in the United States and major accidents in the other modes of transportation. It is not part of the Department of Transportation, nor organizationally affiliated with any of DOT's modal agencies, including the Federal Aviation Administration. The Safety Board has no regulatory or enforcement powers.

To ensure that Safety Board investigations focus only on improving transportation safety, the Board's analysis of factual information and its determination of probable cause cannot be entered as evidence in a court of law. Is what I have bolded the difference you are identifying?
You can read the entire investigative process of the NTSB by going to this link:

Accident Investigations - NTSB - National Transportation Safety Board (http://www.ntsb.gov/investigations/process.html)

CONF iture

5th Oct 2012, 04:43

To answer your question, though rather obliquely, I defer to another part of the same post where I pointed out that Airbus expected its aircraft to be flown by properly trained and competent pilots.
But the best tool I know to attain competency is proper training.

This is where Airbus has to question its lethargy - When it became obvious that UAS were adding up in cruise, especially after the Air Caraibes note, Airbus had to do something.

A red OEB had to be published :

Lately, multiple cases of UAS in cruise have been reported and seem to be related to ice crystals in the vicinity of CBs, temporarily obstructing pitot probes.
The situation can be stressing as AP and A/THR disconnect, ECAM messages pill up, and multiple visual or audio warnings interact such as :

MASTER WARNING
MASTER CAUTION
CAVALRY CHARGE
SINGLE CHIME
C-chord
STALL

Possible sequence of ECAM messages :

http://i35.servimg.com/u/f35/11/75/17/84/ltop_a10.gif (http://www.servimg.com/image_preview.php?i=155&u=11751784)

Additionally :

Sudden decrease of a few hundred feet of the indicated altitude
Characteristic speeds may disappear.
Sudden increase of the TAT

Crews have also reported :

St-Elmo fires
Smell of ozone

Recommended procedure :
At first signs of deterioration, suspect UAS and call for the UAS Memory Item :

AP OFF
A/THR OFF
FD OFF
PF maintain wings level + pitch of 2.5 deg
PNF call any deviation and set thrust to 80% N1

This phenomenon is of short duration, 3 minutes at most according to recorded events, airspeeds are then back to normal.

Notes :

Possibly Alternate 2 Law activates, pitch remains a load factor demand but roll is in Direct Law.
Due to turbulence, brief STALL warnings have been triggered - Maintain recommended attitude + thrust setting except if Stall warning persist in which case the STALL procedure has priority and must be followed.
Disregard the STATUS MSG : RISK OF UNDUE STALL WARNING

We still investigate and bla bla bla ...

Even better if a simulator experience can be provided.
Proper training is a good tool to make us competent.

philip2412

5th Oct 2012, 09:08

Dear clandestino,
Thank you for your post from 3.oct.I trully hope you do believe me,when i tell you something you mentioned in your post was in my mind for a long time.
Why did`nt i post it ? wll it may be because english is not my native language and i was`nt sure that i`m able to do oi right.
You mentioned the missing backgrounds ckecks.I`m just a Slf with interest in aviation and i have reed a few hundreds of accident invest.reports.So that`s my experience and i think i know a little bit more about aviation than the common man on the street.
in ca.90% of these reports there had been a background check of the pilots and i was always thinking that the cause of the accident of AF 447 may lay in the personal structure of the PF.
How was his behaviour on duty,to colleagues,how did he react earlier in stress situations in the cp.How was his behavior to friends or relatives,how did he conduct his private life.
I`m quite sure that it is possible there is maybe something in his past that could explain why he did react that night the way he did.

rudderrudderrat

6th Oct 2012, 10:19

Hi Clandestino,

Thanks for the link to Aviation Investigation Report A08Q0051.

The report mentions:
"2.6.4 Spatial Disorientation and Interpretation of Indications of an Airspeed Indicator Error

From the start of the descent until the reduction in power, the somatogravic illusion due to the aircraft’s acceleration could have suggested that the aircraft had a nose-up attitude when in fact it had a nose-down attitude. The false impression of a nose-up attitude combined with the increase in aircraft speed may have prompted the captain into diagnosing an airspeed indication error."

Yet you say I do know that notion that night makes maintaining attitude in passenger jet more difficult through lack of outside horizon to be utter tosh. You can combine it with the best psychological expertize and still you won't get anything true out of it.

Suppose AF447 crew experienced a similar somatogravic illusion, and the deceleration of the aircraft caused PF to "feel" a nose down sensation. It may help explain why PF was reluctant to believe his PFD.

HazelNuts39

6th Oct 2012, 10:25

A red OEB had to be publishedIsn't that more or less what the Air France "info OSV" of november 2008 contained?

BOAC

6th Oct 2012, 10:33

Quote:
Originally Posted by rrat
Suppose AF447 crew experienced a similar somatogravic illusion, and the deceleration of the aircraft caused PF to "feel" a nose down sensation. It may help explain why PF was reluctant to believe his PFD.

- indeed it might, but do we not expect 'average' pilots to associate rapidly climbing altimeters (x3) with a loss of speed? The essence of ALL instrument training is to believe the instruments where they appear to be reliable and IGNORE 'somatogravic illusion'.

rudderrudderrat

6th Oct 2012, 10:52

Hi BOAC,
but do we not expect 'average' pilots to associate rapidly climbing altimeters (x3) with a loss of speed?
Very true. But throw in the lowest circadian body clock time & no natural horizon. The simultaneous loss of 3 air speeds, and an apparent Altimeter drop of 400ft (due loss of Mach correction). Now which instrument is still telling the truth?

Lyman

6th Oct 2012, 11:36

From 2:10:08 until impact the a/c was in AL2b. (BEA)
...perhaps sooner, but it was annunciated at :08. And even then, crew did not know which AL....

AL2b latches when none of three ADRs is available.
.....which was immediate, and the reason the THS stopped moving

At no time was a/s available to the crew, from 2:10:08 on.... By definition.
...There was no way for them to get whether subsequent speeds were valid. It took the DFDR to explain it, after they were dead.

Whether or not the a/s was demonstrably "accurate" at any time, the pilots could not have known, by definition.

The THS is inhibited when 3ADRs are unavailable, by design...
.....after it started up again, was the LAW changed? The Protections? The DFDR showed it hadn't. Again, after they were dead.

Yet the THS was moving prior to STALL... Whether the crew knew it was moving or not, they had no reason to want to stop it.

By definition, the a/c was demonstrably in the incorrect flight control LAW when the THS was moving... If it moves, Alpha prot must be available, according to Flight Law. So why stop it? Protection applies.

I was taught never to maneuver with trim, trim is trim, not a flight control....

As the aircraft was dissipating energy rapidly, the THS was not trimming, it was flying the aircraft...Once STALLED, the airstream never allowed valid speeds?

So if the ADRs are never available, the crew have no airspeed, ever, by definition. It is unlikely this was trained, 330 pilots here were unfamiliar with 2b.

At times in the critical path, airspeed was "valid" (BEA).
......excellent, how was the crew to know?

NO, it was not valid, not in any useful way. "vitesse feu".

next, Flight Directors....

The FDs were not turned off, nor was A/P, shouldn't this be part of automatic disconnect, along with Thrust? If leaving them active prevents autoflight, how does leaving them on, help recovery? Especilly when they return intermittently, to resume random modes?

CONF iture

6th Oct 2012, 12:55

Isn't that more or less what the Air France "info OSV" of november 2008 contained?
I’m operating the A-330 … but I’m not airfrance.
That’s the Airbus responsibility and duty to publish such stuff.
An OEB has a DIRECT entry in our QRH.
What is an info OSV in the middle of the box letter of an AF pilot …

HazelNuts39

6th Oct 2012, 17:00

What is an info OSV in the middle of the box letter of an AF pilot …Well, if the info OSV was still in their letter box, and they never got the QRH out, ...

gums

6th Oct 2012, 20:18

Gotta admit it, but Lyman has a point:

The FDs were not turned off, nor was A/P, shouldn't this be part of automatic disconnect, along with Thrust? If leaving them active prevents autoflight, how does leaving them on, help recovery? Especilly when they return intermittently, to resume random modes?

As many of we human factor folks and at least one experienced FBW pilot from over 30 years ago ( yep, 30+ steenkeeng years), there is no substitute for a clear, straightforward reversion sequence for the flight control system and same for the displays that the "monitors" seem to use all the time nowadays.

So I give Airbus a "D minus" in that regard. Training and attention to the previous airspeed problems is a whole other topic, and seemed to be ignored by the company/ Air France. I cannot forgive them.

bubbers44

6th Oct 2012, 21:32

I agree with what you are saying gums.

If the PF had done his part with the UAS immediate actions he would have verified AT off AP off and FD off, pitch 5 degrees and climb power. They didn't do that so crashed.

Not everything was AB's fault and training inadequacy's, a great deal was due to pilots not doing their job after thousands of hours experience.

Lyman

6th Oct 2012, 21:46

There was no UAS SOP, none. Every incident was a fresh abnormal, subject to the unquantifiable readiness of the AF crews to instantly interpret what was happening, and deal with no airspeeds, until the Controls Law changed, which it never did.

Straightforward does not mean simplistic, and STALL training should never have become an issue. STALL TRAINING? At the flight levels?

you have got to be kidding.

It was not UAS at the time, it did not have the familiarity it attained on this epic website.

ALTERNATE did not appear until the fourth screen, and the descriptions given here by professionals are not necessarilt the waynit was. Everything in the reort is an interpretation, subject to after the fact pause, and weighing this against that, including politics, and personalities.

The Pilots are quite naturally at the center, and it is exquisitely frustrating to see the slow and measured sculpture of a new urban myth.

NO ONE knows what the screens showed, and that is why the regulators now require CVVR format in future.

If there were usable honest cues on the panel, do you think they would have said nothing about the Attitude until GPWS?

These crew had a dozen seconds or so to get it right, up to the point the cueing got unsussable, imo.....

NeoFit

6th Oct 2012, 23:36

bubbers44 wrote:
If the PF had done his part with the UAS immediate actions he would have verified AT off AP off and FD off, pitch 5 degrees and climb power. They didn't do that so crashed

IF... !

But we do know, with more than 36 UAS events, that it seems difficult to recognize such an event (Thread 7 #1321 (http://www.pprune.org/tech-log/468394-af-447-thread-no-7-a-67.html#post7123396)) :
However, in BEA IR2 was evidence of inappropriate UAS recognition (and therefore incorrect subsequent procedure) by several crews, not just AF447
It seems to me that we must go to "Machine-Man Interface" Thread, rather than "HF" Thr.

Lyman
NO ONE knows what the screens showed ...

But we have some idea:

- PF Erroneous airspeed display between 02:10:07 and 02:11:37 (Final, page 93), PNF between 02:10:07 and 02:10:37

- Fantastic FD pitch orders till 02:11:40 AND stall warrning since 02:10:51 (Final, p 96)

- FD1 + FD2 mostly not available between 02:10:08 and 02:10:47,
and disapeared again at 02:11:40 (IR 3 CVR transcript and Final report)
We know(?) that PF was following FD and pulling up (Final, p 96).
But why NU SS inputs after 02:11:40 ?

- CAS/ISIS CAS out of duty (NCD) beginning 02:12:14 (and computerized again btw 02:13:00 and 02:13:24 (IR 3 CVR transcript),

- Invalid AOA beginning at 02:11:40.

And plenty of "may be", "perhaps" in Final report.

Lyman

6th Oct 2012, 23:41

Hi NeoFit, nice to see you.

Take a closer look at your excellent review of DFDR determined data. Those data cannot be assumed to have been displayed!

Especially not AoA....:ok:

Let me introduce something from what is on another thread. Having to do with displays, let's look at what the pilots were experiencing in the cockpit on the way down. The PITCH was consistently around 16 degrees, the a/c was falling at about 1g, and the airstream is assumed to have been LOUD.

Cover the panel with a tarp, and put hoods on the pilots. No cues, save kinesthetic. The pilot, standing, is on his feet on a 1g floor at an angle of 16 degrees, quite uphill. The pilots, both seated, sense the angle of the a/c in their back and buttocks, also 16 degrees uphill. This continues for two minutes.

And none of these experienced airmen are aware of the deck angle? Of course they knew their Pitch was unacceptably high. No Comment, at all? They ignored it?

To believe the BEA report is to believe in the Mad Hatter, and Rumplestiltzkin

And they had VSI to corroborate their kinesthetics! And Instruments! But, dumbfounded, they descended to their death, unaware of their condition?

nonsense.

NeoFit

7th Oct 2012, 00:03

Hello

Those data cannot be assumed to have been displayed!
Regrettably!

CONF iture

7th Oct 2012, 00:20

Well, if the info OSV was still in their letter box, and they never got the QRH out, ...
The proposed OEB here (http://www.pprune.org/7450265-post577.html) is not to be visited when things happen - Too late for that - It is to be known - It is to be prepared.
On the 4 red OEB I have in my QRH right now, 2 are of that type.

30 known events of UAS in cruise prior AF447 - I feel cheated Airbus kept me in the dark.
Today the average pilot I am is certainly more prepared, not because Airbus informed me, but because AF447 happened ... What a shame !

Clandestino

7th Oct 2012, 22:11

Suppose AF447 crew experienced a similar somatogravic illusion,Impossible. Somatogravic illusion means longitudinal acceleration or decelaration gets interpreted as pitch-up or pitch-down. AF447 was flying steadily when CM2 pulled first time and subsequent deceleration was not very quick anyway, mushing around 0.05 and peaking at 0.1G prior to stall (annex3, page 6)

The simultaneous loss of 3 air speeds, and an apparent Altimeter drop of 400ft (due loss of Mach correction). Now which instrument is still telling the truth? By the time the aeroplane stalled, each and every instrument in the cockpit was telling the truth.

While the UAS was going on, there was no indication any inertial reference was not available or any display unit failed, so with three attitude displays agreeing, it wasn't supposed to be difficult to fly the attitude.

Whether or not the a/s was demonstrably "accurate" at any time, the pilots could not have known, by definition.They knew it was inaccurate. They said it so and then it is not overly difficult to deduce if your speed indication as dropped below minimum needed for sustained flight and you are still flying pretty normally, then the indication must be false.

I was taught never to maneuver with trim, trim is trim, not a flight control....Fact that in every manual, I've used, from C-150 to A320, trim is listed under flight controls. There are proper ways to use it, blanket "don't use it to manouever" just isn't one. It might be applicable for turning the Cessna 172, though.

As the aircraft was dissipating energy rapidly70 kt indicated (appx 118 true) over a minute.

the THS was not trimming, it was flying the aircraft..As commanded by the pilot. Per design. Certified. Proven.

there is no substitute for a clear, straightforward reversion sequence for the flight control systemTrue, but reversion sequence on FBW Airbi is totally straightforward. No matter what law you are in, as long as you have flight controls continuity and are within envelope's lift limit, behaviour of the aeroplane is strictly conventional, nose & wings follow the stick displacement. Now there's another clue you have stalled; if you can't rise the nose with nose-up input or full stick in roll can't help you pick up the wing. Sadly, crew missed even that.

So I give Airbus a "D minus" in that regard. Based on PPRuNe hearsay.

There was no UAS SOP, none. Report explicitly says otherwise.

Every incident was a fresh abnormal, subject to the unquantifiable readiness of the AF crews to instantly interpret what was happening, and deal with no airspeeds, until the Controls Law changed, which it never did. AF crews did experience UAS before AF447. Their control laws did degrade to alternate. They survived. What's your point, again?

ALTERNATE did not appear until the fourth screen,
Who cares! As long as proper control of the aeroplane is not achieved, no ECAM actions are to be done! If crew just did nothing aeroplane would have continued to fly of its own accord, it would not have not gone anywhere near the parameters that would trigger the normal law protections. Unfortunately, picture is messed up in the English version but French report, page 96 refers.

The Pilots are quite naturally at the center, and it is exquisitely frustrating to see the slow and measured sculpture of a new urban myth.OTOH, constantly reproducing the old one about the-guy-whose-name-I-forgot being serious when mentioned that concierges can fly an Airbus is not even funny anymore.

NO ONE knows what the screens showedDisplay units integrity is monitored for the benefit DFDR. Guess what fault was recorded. Yup, none. Anyway, roll disturbance was quickly stopped by CM2, proving he was looking at the functioning attitude display. Also there were references to altimeters recorded on CVR.

If there were usable honest cues on the panel, do you think they would have said nothing about the Attitude until GPWS? They said something about the altitude well before GPWS.

These crew had a dozen seconds or so to get it right, up to the point the cueing got unsussable, imo..... This crew would be far better off with going-into-fear-induced-stupor option than with what they did. Tragic part is that CM2 believed he was saving himself and everyone else on board with his actions, while they were what killed them.

But we do know, with more than 36 UAS events, that it seems difficult to recognize such an eventWell, IAS shows 274 kts one moment and 52 kt next. What could it be? Hitting the anti-gravity field, therefore remaining airborne at speed well below Vs1g?

There were crews that didn't recognize UAS. They did nothing. So survived.

The PITCH was consistently around 16 degreesIt was not. Are DFDR traces really so difficult to read?

No cues, save kinestheticBelieving kinesthetic cues is certain to get one killed when flying in IMC. Proven again and again.

And none of these experienced airmen are aware of the deck angle? Of course they knew their Pitch was unacceptably high. No Comment, at all? They ignored it?
Weirder things can happen when one is scared mindless.

To believe the BEA report is to believe in the Mad Hatter, and RumplestiltzkinWould you be so kind to provide us with plausible alternative?

NeoFit

7th Oct 2012, 23:14

Lyman, I am so sorry, but I don’t agree with your #590 add-on.

I wonder if we have read the same other thread!
I need to read it again because I had understood all the opposite of what you wrote.
… what the pilots were experiencing in the cockpit on the way down.
The PITCH was consistently around 16 degrees,
the a/c was falling at about 1g,
and the airstream is assumed to have been LOUD.

Pitch is not relevant
Liners Pilots are not flying with their pants since a long time, and furthermore, they have order to distrust their sensations (which are often erroneous). The internal ears (semi-circular canals) are not precision gyroscopes.
Watch instruments!

The fall of about 1g
does not seem to me an appropriate remark, because we are only perceiving the speed variations, thus only accelerations change ( positive or negative). 1 g is the earth acceleration, nothing abnormal !!
That to say, when speed is constant, you can’t feel it, flying at FL350 with G/S 550 kt or stalling with V/S 160 kt.

the airstream is assumed to have been LOUD
Yes, of course: “j’ai l’impression” … “crazy speed”

As you wrote previously: “NO ONE knows what the screens showed ...”

Lyman

7th Oct 2012, 23:23

Clandestino:

"By the time the aeroplane stalled, each and every instrument in the cockpit was telling the truth."

Possibly, maybe probably. And the crew were to know this exactly....HOW?

Oh, that's right, the large green bulb, center panel:

"We're valid now, trust me!!"

as if.......

Clandestino:
Quote:
Originally Posted by Lyman
"If there were usable honest cues on the panel, do you think they would have said nothing about the Attitude until GPWS?"

You say:
"They said something about the altitude well before GPWS."

I referenced Attitude, something they never mentioned, and I find that bizarre.

NeoFit:

Quote: Quoting Me....
… what the pilots were experiencing in the cockpit on the way down.
The PITCH was consistently around 16 degrees,
the a/c was falling at about 1g,
and the airstream is assumed to have been LOUD."

After "stabilised" in final descent. Yet they do not reference attitude (NU), only altitude. This to me means they actually did, and the CVR is not released with this data. I simply cannot fathom no mention of PITCH, they have no AoA, and PITCH is all they have to start with, in any recovery. Altitude is fascinating, and informative, but a SYMPTOM, not the CAUSE. How can they have been silent, hint, they were not.....

Clandestino, HERE:

Quote:
Originally Posted by Lyman
NO ONE knows what the screens showed.....

YOU SAY:
Display units integrity is monitored for the benefit DFDR. Guess what fault was recorded. Yup, none. Anyway, roll disturbance was quickly stopped by CM2, proving he was looking at the functioning attitude display. Also there were references to altimeters recorded on CVR.

I am not talking FAULT, you misunderstand. And what the instruments display is decidedly NOT recorded. Only that they are functioning...... That is obvious, NO?

jcjeant

8th Oct 2012, 00:30

This crew would be far better off with going-into-fear-induced-stupor option than with what they did. Tragic part is that CM2 believed he was saving himself and everyone else on board with his actions, while they were what killed them.I disagree ...
Bonin and his co-pilot are telling (to Dubois) that they don't understand what happen and they don't control the plane anymore .. and be sure ...they know what it means !
I don't think someone think he is saving everyone with such arguments !
Actually they hope that Dubois will save everyone (Robert call him frantically) .....

Clandestino

8th Oct 2012, 07:01

I referenced Attitude, something they never mentioned, and I find that bizarre.
My bad, I misread.

Oh yes, they referenced attitude, just not explicitly pitch. CM1 mentions "Horizon" at 2:12:25 and both CM1 and Captain urge CM1 to "get the wings level" from 2:12:54. First GPWS alert is recorded at 2:14:16.

Possibly, maybe probably. And the crew were to know this exactly....HOW?It seems we have to dumb down this discussion down to non-pilot level. By crosscheck. There are three independent pitots, feeding three independent displays, two of which can be switched to fourth source (ADC3). If they agree at the realistic value, and 183kt after one zoom climbs from cruise altitude is realistic, it works. If they don't, check that all three AIs agree and fly any of them. When I trained for PPL, pitch and power circuits were part of PPL syllabus and it was not fifty years ago, it was in 1996.

What overwhelmed the crew of AF447 is very similar to (and IMHO probably the same thing) that which wiped the crews of KAL 8509 (http://aviation-safety.net/database/record.php?id=19991222-0) and Birgenair 301 (http://aviation-safety.net/database/record.php?id=19960206-0) out of existence. First time they were faced with a bit more serious anomaly in flight was when they first really realized that the air is a dangerous place to be and they had no clue how to get out of their predicaments. As was predicted long time ago:

The fact that you've got Air Line Transport Pilot written on your license doesn't mean you fly any better. One day these pilots who fly for the money of the job, they're going to lose everything, the cockpit's going to burst or some such thing and they'll be left with a stick and rudder and they won't know how to fly.

Yet they do not reference attitude (NU), only altitude. This to me means they actually did, and the CVR is not released with this data. Are you accusing BEA of deliberate falsification?

How can they have been silent, hint, they were not.....Of course they weren't but CVR mostly recorded the utterances consistent with being confused and clueless.

I am not talking FAULT, you misunderstand. And what the instruments display is decidedly NOT recorded. Only that they are functioning...... That is obvious, NO? They are the instruments that work reliably for thousands of hours and all of a sudden they fail simultaneously, at the exact time airspeed goes unreliable, with bizarre fault that doesn't trigger DU monitoring. Yeah, right. For the record: I wasn't the one that first mentioned "Mad Hatter" in this thread.
I disagree ...How come?

Get the French report, go to page 96. If you are struggling with French: blue line is DFDR readout, red line is produced by simulator fed by winds and control inputs from DFDR. Blue and red are match. Magenta is simulator without any input on the stick.

Do you get it?

Bonin and his co-pilot are telling (to Dubois) that they don't understand what happen and they don't control the plane anymore .. and be sure ...they know what it means !They are right; they didn't control the aeroplane anymore because CM2 has chased it away out of control and CM1 did not stop him! Both were pretty clueless from the start of the event.

Actually they hope that Dubois will save everyone (Robert call him frantically) ..... Airborne equivalent of "Help, daddy, help!". It is tragic that when they realized that flying is no children's play they were left with only minutes to live. Not unprecedented, though.

Lyman

8th Oct 2012, 12:09

Clandestino..

"Oh yes, they referenced attitude, just not explicitly pitch. CM1 mentions "Horizon" at 2:12:25 and both CM1 and Captain urge CM1 to "get the wings level" from 2:12:54. First GPWS alert is recorded at 2:14:16."

Pitch is all they had to refer to, they had no AoA. Of course it was not wack as AoA, but it was well out of cruise values?

And even AoA was not extreme until after the a/c STALLED....

I appreciate your patience, I stopped flying before you started. 1996?

jcjeant

8th Oct 2012, 13:28

Airborne equivalent of "Help, daddy, help!". It is tragic that when they realized that flying is no children's play they were left with only minutes to live. Not unprecedented, though. I agree ....
I admire your honesty and do not use convoluted language to say that these two pilots (maybe three pilots) were qualified to fly an Airbus A330 that only when all goes well
The only thing that could invalidate this constatation would know at least one of these pilots had already in the past saved a aircraft in disarray
Unfortunately it seems that the BEA (human factors) have not investigated it .. or find nothing .. or does not echo in the final report
It is the responsibility of training schools .. the regulator and Air France that is committed

rudderrudderrat

8th Oct 2012, 18:41

Originally Posted by Clandestino
Impossible. Somatogravic illusion means longitudinal acceleration or decelaration gets interpreted as pitch-up or pitch-down. AF447 was flying steadily when CM2 pulled first time and subsequent deceleration was not very quick anyway,

The PF on AF447 attempted to recover the Altitude loss of 400 ft (due loss of mach correction), but for some unexplained reason he continued to pull achieving 7,000ft per min RoC. According to the final report http://www.bea.aero/docspa/2009/f-cp090601.en/pdf/annexe.03.en.pdf the graph of ground speed shows a reduction from about 500 kts to 400 kts in 30 seconds (between times 02:10and 02:10:30). i.e. about 3 kts per second. Apparently you don't believe that rate of deceleration could cause a somatogravic illusion.

Yet from the incident report of Air Transat Airbus A310-308 C-GPAT (to which you posted the link happless crew (http://www.tsb.gc.ca/eng/rapports-reports/aviation/2008/a08q0051/a08q0051.asp)), says
1.11.4 “At about 1440:44,” (I think they meant 19:40:44)“ at the end of the climb, the perceived attitude reached greater than 30° whereas the actual attitude was about -3°.” (Due to Somatogravic illusion).

The table in Appendix A shows the aircraft speed and time base.The aircraft accelerated from 0 at 19:39:38 to 209 kts by time 19:40:44 (i.e. 66 secs or about 3.1 kts per second) and produced a somatogravic illusion of 30 degs error in perceived pitch.
The fastest acceleration I can see is between times 19:40:44 at 209 kts and 19:41:29 at 345 kts (VMO) i.e. 136 kts in 45 secs again about 3 kts per second.

Please explain why the crew of C-GPATcould have suffered from Somatogravic illusion with an acceleration of 3 kts per second, but according to you, the crew of AF 447 could not have.
Impossible?

roulishollandais

20th Oct 2012, 17:59

We needed from BEA a total description of the differents laws ; why, how, rejection, etc. We are here trying to guess details to rebuild analogy.

Why could the BEA not provide that analysis ???

The BEA report (s) does not apply on scientific method (thesis), nor on juridic method. The result is that increases the role of the Court(s) in Aviation. Who wants that ? :(

jcjeant

20th Oct 2012, 19:47

BEA has explained how the accident happened
Justice will seek to explain why the accident happened
Doing .. they will find out who is responsible ( if any ) .. that BEA can not
BEA's investigation and the trial court are therefore complementary and two inseparable things to know all the truth about the accident
Actually we know only the half truth ....

Lyman

20th Oct 2012, 20:00

roulishollandais, jcjeant.

If at Court it is requested, can BEA be required to disclose data that is not published?

If so, who would argue for no further data, someone who is fearful? Who could object, who has the right to do so, eg standing

roulishollandais

22nd Oct 2012, 17:16

@Lyman
Yes.
The Court is free to make a search at BEA, AIRBUS, AIR FRANCE, Thales, DGAC, etc.. ("perquisition"). It is the "Juge d'Instruction" (the most powerful person in France) who comes himself whith Police, and take everything they want. Nobody knows before they are on the door.(Soulez-Larivière, during the Rainbow Warrior case himself could not avoid perquisition in DGSE ! from Policeman of New-Zealand)...

There was a time where the victims/families did not appeal the Criminal after an airliner crash, only Civil action. It really started with Habsheim and the magic aircraft who "cannot stall".

DozyWannabe

25th Oct 2012, 00:26

There was a time where the victims/families did not appeal the Criminal after an airliner crash, only Civil action. It really started with Habsheim and the magic aircraft who "cannot stall".

The aircraft at Habsheim never did stall - it's the reason almost all the occupants walked away. The main reason it crashed was because the pilot in command (described on one occasion as the most arrogant man the interviewee had ever met) thought he was good enough to disable the A/THR safety features and fudge a flypast rather than swallow his pride and attempt another approach.

His legal team was responsible for almost all the inaccurate statements made about the design to this day. The irony is that the BEA report considered Air France's actions more responsible for the accident than those of the Captain, but you wouldn't know that because of all the rubbish talked over the years.

jcjeant

25th Oct 2012, 08:15

Year 1988
Habsheim crash
Year 1996
First trial
Year 2008
End of the justice procedures .. case closed
In my opinion the case of AF447 may last even longer and the result will be
Airbus will continue to sell and construct aircrafts
Air France will continue to transport passengers
DGAC and EASA will continue to regulate
BEA will continue the investigations jobs
The losers are the victims and their families
Moral suffering .. financial losses ... etc. .. whatever the outcome of the trial

roulishollandais

26th Oct 2012, 20:18

you wouldn't know that because of all the rubbish talked over the years.

I was living in Alsace and could follow the first trial !

Really nobody during the trial thougt or said A320 could not stall, with one exception : the copilot MAZIERES. He said to the Court "Je croyais que l'avion ne pouvait pas décrocher" ("I thougt that the plane could not stall").
Nobody said something at that moment, other that Pierre BAUD saying it is a problem of "energy" (nothing about AoA...). MAZIERES seemed to still be convicted of what he said, and his face seemed to say he could imagine no shematic of another way to fly A320. That is what I have seen and listened.

From ASSELINE I never listened during the trial that the aircraft would have stalled, nor that the aircraft would have been stalling. His book "Le pilote est-il coupable ?" reflects the same things he said during the Trial.

About ASSELINE, I first want to say about his legal team, the Laywer died quickly after the Trial. Me Michel AGRON was an helicopter pilot, and seemed not to be an impulsive or an unprudent man. He wanted to understand how that aircraft was flying.

I was really estonished to hear that A320 pilots knew so little about that aircraft : ASSELINE who was the first A320 pilot from Air France, explained that he had to teach the other pilots, as he was the A320 Sector Chief. He needed a simulator, and THOMSON (today... THALES !!!) decided with him and AIR FRANCE to provide it. So they asked to Airbus the description of the flight laws. Airbus refused but said they could provide a closed box whith a computer. THOMSON and ASSELINE accepted (no other deal possible). And ASSELINE trained himself on that blind computer !

He tried to do the anavoidable "tours de piste basse altitude". And finally he discovered he was able to do them at 100 Ft, not with the height sensor, but only with the altimeter. To do that he needed to cut the protection alphafloor, what he did at HABSHEIM. Pierre BAUD who was present at that moment said (smiling) to the Court he was right, he needed. And nobody said anything, assuming ASSELINE was able to fly without stalling without that protection and without A/THR. The Court asked nothing about that. The trial report or notes would show it.

That is what I have seen and listened that day.

ASSELINE said also - during the Trial , I say it again - that after that, he explained to AIR FRANCE he was able to fly with the (baro)-altimeter at 100 Ft. And AIR FRANCE who had NO MEAN to evaluate if it was feasible or not and trusted Captains, accepted to allow him what ASSELINE said to be able. (Well readed regulations surely did not allow to do that, but remember it was the time where CONCORDE was doing a go-around over the most known French meeting of the FERTE-ALLAIS at 50 Ft, and other AIR FRANCE planes over the town (parc de VINCENNES) whithout any crash zone other than houses, and all national meetings like PARIS LE BOURGET airshow, or military meetings were used to show aircrafts flying very low over the people, with pilots from many countries... ".Que celui qui n'a jamais péché lui jette la première pierre"/(Let he who is without sin throw the first stone). Despite that regulation problem, I am not sure the Court took these "details" in consideration.

You say ASSELINE was arrogant : after the accident at that public Trial, I have to say I have seen a man who still searched how that aircraft was working with his blind sealed computer box.

Some mistake has been made between Air France and the Habsheim airport, but I am not sure that the Court evaluated that : People were placed along the grass runway, and not along the concrete runway and ASSELINE has been surprised to change the approach. Here, Dozy, you are right, ASSELINE would have to go-around and come back for a second approach toward the grass runway. Both runways were too short to land.
Not sure the Court took that in consideration... that has not been discussed as far I know, I have seen, I heard. I discovered also that the grass runway (who was used daily by the airclubs and flight schools) was not legal too, trees too high at the extremities... for the lightest aircrafts... That has not been discussed at the Trial, despite the President of the airclub, chief of the airfield was possible culprit.

Would ASSELINE have done a second approach, he would have been too low over the trees to respect the 100 FT ASSELINE was able to fly on the THOMSON "simulator" with its blind sealed box and he could not know it...

Something was really strange, many newspapers and rumours said since years that the aircraft COMPUTERS would have been the cause of the lack of ASSELINE to be able to go-around and specially the limitation of 2.5g start the climb quickly (not engine problems) : loss of height decreases if load increases. But the Court has never questioned about a computer or automation failure : the reason is that NOBODY from the experts and the Court was able to do that analysis at that moment ! The trial has been conducted as a very conventional aircraft crash. Only BAUD and BENOIST gave a video about system, but initiation level 000, max that people there were able to understand... Victims had a witness who had to ask some about computer certification, but another DGAC certifyer was there as a Prosecutor expert, who had done thousands certifications (he said in private) for aircrafts without such computers. So the automation of A320 has not been examined by the Court.

To forget nothing important from that trial, mention must be done to NORBERT JACQUET : himself who doubted of the Airbus safety in AIR FRANCE, has not been able to critisize the systems, and did not try to do it. He was focused on DFDR possible change, and he himself tried a trial he failed. Despite that, at the ASSELINE trial, a last test has been done about his theory : The end of the magnetic tape would have been folded in case his theory of DFDR change would finaly by proved. And I can remember this strange... (and funny !) scene where two mens were left and right before the Court, 6-7 meters from one another along the opposite walls, enrolling the entire tape to the last meters, in a hitchcok suspense : there was no folders. (I could never understand from where these folders would have came). But that was not the reason that put NORBERT JACQUET out of our world ! Since the very first day of the accident, he refered to a phone message he had lost to a good friend of him (witness of NORBERT JACQUET 's marriage) working very close of the Ministre des Transports, to remember him his accident prevision, in AIR FRANCE, on AIRBUS, he did BEFORE THE CRASH. And IMMEDIATELY SOMEONE IN AIR FRANCE, tried to discredite him... This part of the HABSHEIM story is particulary SAD !

I do not know what happened to you Dozy, I feel something we do not know was very sad for you two, and I respect that, you surely have good reasons.

Iself, as pilot AND computer guy, my position is since more than 40 years that scientists and experts have a great responsibility they are not allowed to go under.

Pilots, Passengers, Public and members of automation and computing team, are allowed to can trust in safety, and only scientific transparency allows that. :)

AlphaZuluRomeo

26th Oct 2012, 22:11

jcjeant, take care, your last post coud be read as if you thought "abnormal"/"unsatisfying" that the organizations/companies you quote do not simply ceased to exist, due to some justice decision.
That would be vengeance (?), not justice.

roulishollandais, I can't see how an AoA protection (alpha prot / alpha max) would prevent to fly at 100ft? Are you sure you didn't mean the automatic TOGA engagement (i.e. alpha floor) instead?
With alpha floor disengaged/forbidden, but normal law still in force (Habsheim's configuration), alpha prot/max protection still applies and the aircraft will do its best to avoid stalling... :ok:

Regarding your: "Would Asseline have done a second approach, he would have been too low over the trees to respect the 100 FT Asseline was able to fly on the THOMSON "simulator" with its blind box and he could not know it..."
I'm sorry, I don't understand what you mean, here... :confused: Would you be so kind as to elaborate?

And finally, about the g protection hypothesis (i.e. the limitation to +2.5g which would have prevented Asseling to start the climb quickly):
This hypothesis is null & void as per the BEA report (which, by the way, does examine what you call "the automation of A320").

roulishollandais

27th Oct 2012, 14:43

Hi AZR,

You are right AZR : it is not "alphamax" but "ALPHAFLOOR". I discovered my mistakes when I was far from internet connection, and thought Dozy would not miss the target !:E You were the first ! ;) Thank you for immediate correction to avoid some wrong idea development.

"tout calcul non vérifié est à-peu-près certainement faux" (Kaufman)... it is the same with the posts...:(

RetiredF4

27th Oct 2012, 14:58

Ineresting presentation from Royal Aeronautical Society Heathrow Branch
The Sir Richard Fairey Lecture
Training to avoid Loss of Control 12. Oct. 2012 (http://www.google.de/url?sa=t&rct=j&q=+Bill+Wainwright%27s+comments+on+the+combined+manufacturer s%27+recommendations+on+using+rudder+in+upsets&source=web&cd=3&cad=rja&ved=0CCoQFjAC&url=http%3A%2F%2Fwww.dibley.eu.com%2FHDRAeSLHRBranch121012-TrainingtoAvoidLOC-IAccidents-15oct12.pptx&ei=bueLUMWGBaj14QT0mICoCQ&usg=AFQjCNG-wepYRGesf_q6fpiK4r-4yh_YWQ)

DozyWannabe

28th Oct 2012, 00:42

@roulishollandais:

I only pop in from time to time at the moment, as I'm very busy with work.

The flight control computers, far from a "black box", were probably one of the most strictly-specified designs of their day. Given that the flight laws, the consequences of those flight laws and what triggers them are part of every conversion and training course on the A320 and her sisters, I think it unlikely that Airbus refused access to a "description" of the flight laws. The underlying logic maybe - but to a non-computer scientist this information would be meaningless.

As I recall, as part of the investigation, AF provided the BEA with documents still in force that prohibited display flights below (if I recall correctly) 600ft. If they gave Asseline the go-ahead to do so then the people responsible were negligent in not being aware of that rule.

Another poor judgement call by AF was in providing Asseline and his crew with charts of the Mulhouse airfield that were *photocopies* of the only one they had on file. This becomes important when it comes to the decision-making behind trying to fudge the flypast rather than turn around and try again. The photocopier they used was black and white rather than greyscale, and the graphic indicating trees at the end of the grass runway was of a grey too light for the photocopier to pick up - so if the crew checked their photocopied charts as they approached then they would have determined that the end of the runway was clear of obstruction because the copies were missing that information. This is the reason why the crew stated that they weren't expecting the trees at the end of the runway to be so high.

In the event, as AZR states, by disabling (rather than disengaging) autothrust - and as a consequence alpha floor, Asseline painted his aircraft into a corner that left no margin for error and there is no excuse for that - even less so with passengers in the back.

As for aircraft behaviour, the BEA's lead investigator on the case put together a test which set up one of the longest runways in Toulouse to mimic the approach made by Asseline based on the DFDR data, and what they found was that it was alpha protection that prevented the aircraft from pitching further up than it did. As Asseline asserted, it prevented a pitch up beyond a certain point, but what it was doing was preventing a stall because the airspeed was not sufficient to climb. If the aircraft had followed his pitch-up order, it is likely that the aircraft would have stalled short of the trees, likely resulting in an unstable crash and many more deaths than actually occurred.

There were no secret software errors and no significant technical failures - simply a pilot who took a gamble, in part because of erroneous information supplied by his employer, and lost with tragic results. The irony is that if Asseline's legal team had focused on AF's negligence rather than trying to cause controversy over the aircraft, he'd likely have had a much better case when he went to trial. Why he did not take this option is a question only he can answer.

Unfortunately because of the way aircraft accidents are essentially handled by the judicial process in France, a lot of rumour and counter-rumour was generated by the legal teams of those involved, which have obscured the facts under a mountain of legalese. The press were simply repeating the press releases from each legal team as they came - there was no attempt to check the veracity of what they were saying.

CONF iture

28th Oct 2012, 03:54

In the event, as AZR states, by disabling (rather than disengaging) autothrust - and as a consequence alpha floor
A/THR was disconnected, nothing more.
Where is that BEA quote that states otherwise ?
And what does it change as the radar altitude was already around 30 feet ...

... and what they found was that it was alpha protection that prevented the aircraft from pitching further up than it did. As Asseline asserted, it prevented a pitch up beyond a certain point, but what it was doing was preventing a stall because the airspeed was not sufficient to climb. If the aircraft had followed his pitch-up order, it is likely that the aircraft would have stalled short of the trees, likely resulting in an unstable crash and many more deaths than actually occurred
Will you ever stop repeating the same nonsense over and over ?
For a given AoA corresponds a specific airspeed and that is not the airspeed that was not sufficient for the aircraft to climb, that was the thrust.
The system prevented the aircraft to reach and maintain alpha max so correct now once for all those misconceptions of stall and more deaths.

DozyWannabe

28th Oct 2012, 04:50

A/THR was disconnected, nothing more.
Where is that BEA quote that states otherwise ?

I don't know, but it's common knowledge that the disconnect button was held down, thus not only disconnecting, but also disabling A/THR.

The system prevented the aircraft to reach and maintain alpha max so correct now once for all those misconceptions of stall and more deaths.

Alpha max is unlikely to have helped. Sure alpha prot holds the pitch just shy of alpha max, but not by a significant degree. With neither sufficient thrust nor airspeed to climb the result would have been the same.

jcjeant

28th Oct 2012, 06:04

All is there (in french of course)
Histoire du crash de habsheim (http://www.crashdehabsheim.net/l%27historique.htm)

AvMed.IN

28th Oct 2012, 08:43

Besides everything else, tragedy of flight AF 447 was that the temporary inconsistency of measured airspeed and autopilot disconnection, was compounded by “inappropriate control inputs". This brings to focus an overdependence on automation (http://www.avmed.in/2012/10/old-facts-new-insights-surprises-in-glass-cockpit/) at the cost of basic piloting skills!

jcjeant

28th Oct 2012, 09:07

(http://www.avmed.in/2012/10/old-facts-new-insights-surprises-in-glass-cockpit/)overdependence on automation (http://www.avmed.in/2012/10/old-facts-new-insights-surprises-in-glass-cockpit/) at the cost of basic piloting skills!
Interesting study

Lemurian

28th Oct 2012, 13:56

I was really estonished to hear that A320 pilots knew so little about that aircraft : ASSELINE who was the first A320 pilot from Air France, explained that he had to teach the other pilots, as he was the A320 Sector Chief.He was not the sector chief pilot, merely the "senior training captain" ans as such he was responsible for the training of all pilots joining the 320 fleet.
He needed a simulator, and THOMSON (today... THALES !!!) decided with him and AIR FRANCE to provide it. So they asked to Airbus the description of the flight laws. Airbus refused but said they could provide a closed box whith a computer. THOMSON and ASSELINE accepted (no other deal possible). And ASSELINE trained himself on that blind computer !
You've either misunderstood the mission given by AF to A., which was to define a requirement for in-house simulators and for which he performed some 150 hours sim time with AeroFormation and Thjomson or you're quite a bit disingenuous. Contrarily to what you are saying about Airbus "hiding" the flight laws, these were well known by all airlines and included in the syllabus of the typre-rating at AeroFormation. I personally saw these original programs in a few airlines' VAC Bi .

You say ASSELINE was arrogant : after the accident at that public Trial, I have to say I have seen a man who still searched how that aircraft was working with his blind sealed computer box.
And I met him in Colombo in June '90 as I was being line checked on the 743 ; didn't know him but he came to the flight deck after getting some french newspapers from the girls at the back. when my check captain came back, they had a rather heated conversation, the guy being a bit graphic about how he was about to "stick it dry to AF and all"...
When he left, the checker had just these words to say : "For someone who shoud be bearing the death of three innocent people on his conscience, this man is in my opinion a bit too imbued with himself "...

Some mistake has been made between Air France and the Habsheim airport, but I am not sure that the Court evaluated that : People were placed along the grass runway, and not along the concrete runway and ASSELINE has been surprised to change the approach.
That's a load of bull if I ever saw one : There was no preparation at all about this fly-by, something that was his responsibility to have done.He eventually lined up his trajectory with the grass strip
As for the rest of your post, it just smacks of total un-understanding of aviation subjects, including av laws. If you're a pilot, I'm not surprised any more with the level of safety achieved by french pilots... of course, conspiracy theories are somehow more important than technical knowledge.

CONF iture

28th Oct 2012, 14:23

I don't know, but it's common knowledge that the disconnect button was held down, thus not only disconnecting, but also disabling A/THR.
DozyWannabe don't know but keeps pushing theories based on common knowledge.

Very interesting from someone who pretends to fight such attitude (http://www.pprune.org/7489485-post364.html) :
Rebutting scuttlebutt, "common knowledge" and opinion that I know to be debatable by using fact is not a sign of disrespect, it's because I genuinely want to learn and get to the bottom of why there is so much resistance from some camps - and hopefully get everyone talking from a factual standpoint so the discussion can progress.
Waiting for the facts not common knowledge ...

Lemurian

28th Oct 2012, 15:04

Confiture :I don't know, but it's common knowledge that the disconnect button was held down, thus not only disconnecting, but also disabling A/THR.
DozyWannabe don't know but keeps pushing theories based on common knowledge.
Waiting for the facts not common knowledge ...
Easy. Just the BEA official report :
§1-11-3 :... at the beginning of the taxi to takeoff, FO asks Capt to confirm his intentions for the fly-pasts... Capt says he will perform the first presentation with config 3, gear down at 100 ft and max AoA, the alpha floor function disabled... FO wil manually adjust thrust in order to maintain level flight...
and on the dfdr reading at 12.41.58 : "Je déco... braye l'automation ( "I discon...disable the automatics...")In >french, déconnecté -disconnected - is not débrayé - disabled, taken off-line. Capt's reverting on the correct term is quite telling.
As it ghappens, the disabling of the Alpha floor function didn't have any influence onj this accident, as they went quickly below 100 ft, when they wenht first into C* - i.e N demand around 1G- and then into pitch ref function.
Apparently, Dozy has a very good memory... unlike some here.

CONF iture

28th Oct 2012, 18:35

Apparently, Dozy has a very good memory... unlike some here.
Too bad your references are based on cvr, just not fdr.

His intention was to disable A/THR but did he do it ?
NO

When he was going to do it at time 12 41 58 he was distracted or interrupted by a landing gear issue. Thirty seconds on a disconnect switch is a long period. What he did at that time was disconnecting the A/THR, nothing more.

And if he had done it at that time, why does he mention it again at time 12 45 26 when the aircraft is already at 40 feet RA :
Bon, j’vais bien là, débrayer l’auto-manette.

Dozy does not read French, you do, so come up with the BEA quote which would state that the crew in Habsheim had permanently disabled the A/THR.
If they had, I assume it must be clearly stated somewhere in the BEA report …

Memory is not always enough ...

Owain Glyndwr

29th Oct 2012, 08:38

The final BEA report on Habsheim says:

In section 1.1 Déroulment du vol,

Le décollage a lieu à 12h 41, immédiatement suivi d’un virage à droit pour rejoinder Mulhouse-Habsheim à une altitude de 2000 pieds QNH (soit une hauteur d’environ 1000 pieds par rapport au sol) atteinte à 12h 42.
Pendant le vol en palier à 1000 pieds sol, l’autopoussée est debrayée pour permettre un contrôle manuel de la poussée et deux séries d’alarmes liées à la configuration train rentré et deux indications de radioaltitude inférieure a 1000 pieds sont entendues. L’autoroute est utilisée comme premier repère de navigation à vue, puis un chemin, pârallèle à l’autoroute et menant au terrain d’Habsheim.
A 12h 44, l’avion quitte son altitude de vol en palier pour descendre vers l’aérodrome quie est identifée a vue. Les moteurs sont réduits. L’extension des volets et du train d’atterrissage est faite au début de la descente.
And again in section 1.11.3. Restitution des conversation et des alarmes sonores (CVR)

Le décollage a lieu à 12h 41, l’autopoussée est débrayée dès la rentrée du train et des volets en position 1.
That seems clear enough to me

CONF iture

30th Oct 2012, 01:20

L’autopoussée est débrayée pour permettre un contrôle manuel de la poussée
That’s exactly what it is.
A/THR is disconnected to allow manual control of the thrust.
Nothing else.

To not be confused with :
L’autopoussée est débrayée de façon permanente afin d’inhiber l’activation d’ALPHA FLOOR.
A/THR is permanently disconnected to inhibit Alpha Floor activation.

FCOM
The A/THR system is disconnected for the remainder of the flight.
ALPHA FLOOR is lost.

Lemurian

30th Oct 2012, 11:51

A/THR is disconnected to allow manual control of the thrust.
Nothing else.

To not be confused with :
L’autopoussée est débrayée de façon permanente afin d’inhiber l’activation d’ALPHA FLOOR.
A/THR is permanently disconnected to inhibit Alpha Floor activation.
This is absolutely typical of your tactics : selective quoting and selective memory.
You can't have it more than one way : either reject the whole report - as you've done in many instances - or accept everything in it.
On a previous post, I quoted the transcribed pre-takeoff briefing the captain gave the FO :
Au début du roulage à 12 h 29, le copilote demande au cdb de confirmer les éléments prévus pour les passages à Habsheim. Celui-ci indique qu’il effectuera la première présentation en config volets 3, train sorti à 100 pieds, à l’incidence maximale, Alpha floor débrayée, le copilote ajustant la poussée pour tenir le palier… à la demande du cdb, le copilote affichera la poussée maximale des moteurs, le cdb effectuant alors une montée en virage…
What is really tragic is that he planned a deliberate dangerous manoeuvre with passengers on board, without any preparation except what he'd seen Airbus test pilots perform routinely. All went to hell because, after all and in spite of his very high self-esteem, he wasn't up to the piloting task, never understood the vision geometry -at a high nose-up attitude- involved and eventually was responsible for the deaths of innocent people.
Had the airplane had anything sinister about it, it believe it would have been revealed... that 25 years later, there are still people to defend the most reckless flying with pax on board is totally beyond me...
Of course, I'm not naive enough to ignore that some do have a very definite agenda...

Lonewolf_50

30th Oct 2012, 13:08

I had the mistaken impression, when I saw a new post, that something about AF 447 (or some bickering about AF 447) was added to the thread, even though the blood has mostly been squeezed from that rock some time back.

The topic of this thread isn't the Habsheim crash.

It is AF 447, which conversation seems spent.

Respectfully request the bickering on the Habsheim accident be taken to a thread concerning that accident, gentlemen.

CONF iture

30th Oct 2012, 13:48

Respectfully request the bickering on the Habsheim accident be taken to a thread concerning that accident, gentlemen. You are absolutely correct - I had already promised to do it ... as every Airbus event brings us in a way or the other back to Habsheim.
But there is no bickering here, there is only stuff that needs to be discussed.

CONF iture

30th Oct 2012, 15:05

Respectfully request the bickering on the Habsheim accident be taken to a thread concerning that accident, gentlemen.
Sorry Lonewolf, I guess I'll have to reply to Lemurian here as my thread on Habsheim is not accepted for now by the administrator.

Organfreak

30th Oct 2012, 15:49

Lemurian said to CONF iture:
You can't have it more than one way : either reject the whole report - as you've done in many instances - or accept everything in it.

I'm sorry, that simply defies logic. Would anyone here do the same with the BEA Report on 447? No, they would not. What is black-and-white about piloting? Nothing. I'll now return to hibernation. :bored: G'nite!

Lyman

30th Oct 2012, 16:13

I think there are important parallels, Confiture.

In both accidents, the aircraft had 'settled in', and the pilots, for different reasons, were unable to modify the flight path. Asseline had established a short final, and Pitch had the appearance of being on some mechanized value, sinking slowly as if to land, the engines did not change attitude, even though they had spooled up before the trees. Dozy is right, had the airplane Stalled, they likely all would have died.....

But it did not, it sank slowly as if to settle on the runway, having done the "retard" thing. Unfortunatley, there were trees on the 'runway'.

Had Airbus programmed their peachy "Escape" from CFIT at that point?

Question? Is TOGA escape available at the cruise levels? In ALTERNATE LAW?

Because at one point, 447 had flight parameters of a 330 on short final.

Unfortunately, she was above 38000 feet at the time, and ballistic.

TSR2

30th Oct 2012, 16:34

Having seen the recent documentary on the crash of AF447, one thing puzzles me. During the programme it was stated that the rate of descent was '10-15,000 feet per minute' and yet non of the three pilots seemed to be aware that they were in a stall until reaching 4,000 feet. Surely at that rate of descent the pilots would have felt something that may have given them a clue.

cwatters

30th Oct 2012, 17:08

Falling = weightless = empty feeling in stomach.
vs
Decending at constant velocity = 1g = feels normal.

They knew they were descending but not the reason why.

HazelNuts39

30th Oct 2012, 17:16

Because at one point, 447 had flight parameters of a 330 on short final. At what point?

Lyman

30th Oct 2012, 17:24

Nose high, sinking, approaching STALL, under power.

HazelNuts39

30th Oct 2012, 17:42

Sinking on approach to stall?

BOAC

30th Oct 2012, 17:54

....and silly me - there I was thinking they were already stalled too - what WERE they doing?:ugh:

PS Don't fancy flying wiv 'im. Going up should be ok, but...................

Lyman

30th Oct 2012, 17:55

Howdy

HazelNuts39 Sinking on approach to stall?

Yes, though perhaps perceptually only, (reducing Vs)

'sinking' then. Let me add 'slow' As well. (<60 knots) With the STALL warn to seal the 'illusion'.......

Lyman

30th Oct 2012, 18:34

Hi BOAC

BOAC "..and silly me - there I was thinking they were already stalled too - what WERE they doing?"

With respect, it is of no consequence what you were thinking, v/v 447.

They were thinking they were not already STALLED.

They had no access to the data you have.

bubbers44

31st Oct 2012, 01:02

Air France 447: Final report on what brought airliner down - YouTube

Lyman

31st Oct 2012, 01:29

bubbers44....

Thank you for that. That pretty much puts to rest the debate re: SS/yoke.
Sullenberger is not anonymous, and seemingly has no bias.

Case closed.....

TTex600 and CONFiture, a question.. From the video. Full aft stick shows the handle's remaining cant of approx twenty degrees forward. From this geometry, it would seem Airbus have incorporated a bias to back stick, and left NOSE DOWN as more difficult to gain v/v stick angle. Your thoughts? Full forward stick looks to require forearm push PLUS wrist rotation, is that it?

Is that an engineering artifact? A remnant of overconfidence in the aircraft's protection against extreme NU commands?

Full back stick looks alarmingly comfortable. is it?

HazelNuts39

31st Oct 2012, 09:28

Sullenberger is not anonymous, and seemingly has no bias.
No bias? I wonder.

Lyman

31st Oct 2012, 14:36

Hi HazelNuts39

"HazelNuts39
Quote:
Originally Posted by Lyman
'Sullenberger is not anonymous, and seemingly has no bias.'
No bias? I wonder."

You know, that is an interesting observation.... I think, pedantically, that any opinion is by definition a bias.

So it requires some critical thought...... He is a paid professional, and has been the owner of an Aviation Safety Consultancy for some time.

At some point, should scepticism be suspended in favor of practical purpose?

In my opinion, no my bias, I would say of course. In the video, he is sitting in the right hand seat, and we know he was a Captain, probably flying exclusively from the left side. Does that hamper his assessment?

The question addressed in the video had to do with visibility of the stick, as did BEA in their report, not interconnectivity. So we have BEA making a point of acknowledging the difference between Airbus and the Boeing architecture, and now Sullenberger more or less damning the layout as deadly, when compared in this way. (The accident would have been less likely, according to Sully).

I live nearby three Airbus pilots, all retired, who unanimously think the difference was unimportant to them.

The bottom line? What do the regulators and the operators think should be done, if anything?

For most folks a risk/benefit analysis suffices. What is the advantage of isolating the control devices visually?

gums

31st Oct 2012, 17:59

I had not seen Sully's opinion of the accident. Thanks for reminding us.

So I hear the narrator describing the onset of the accident - loss of the speed inputs and A/P disconnects. Then Sully talks about the constant back stick. As with Sully, most here will never understand the thinking of the PF. He may have still thought " I can't stall this jet".

So I posit we maybe should look at the A/P reversion modes as much as the FCS reversion laws.

In short, why not simply go to an "attitude hold" mode if only speed inputs are FUBAR? My archaic VooDoo had such a mode called "control stick steering", and was limited by AoA and gee. If you relaxed on the stick the sucker maintained an attitude, and not an AoA or gee. The AoA limiter would come into play long before the gee limiter.

For those flying the 'bus, just put in a tiny back stick that is commanding 1.1 gee versus 1.0 gee. And with all respect for Doze, the system commands a gee, not an attitude or AoA. The THS will trim to reduce the reuirement to hold that tiny back stick, right? But if I continue to hold it, the THS will move more and my pitch attitude will continue to rise. No need to hold full back stick. Just a timy amount will provide the same thing we saw with AF447's pitch.

So my idea is to look at the A/P reversion as much as the flight control law reversion. If the gyros/accelerometers are still working, then the crew has some time to figure out what's going on. No need to go "full manual" in a back-up control law.

What do the 'bus drivers here think?

CONF iture

31st Oct 2012, 21:05

Full back stick looks alarmingly comfortable. is it?
Not that much - It takes effort to maintain it at the full aft position - More noticeable when practicing the PULL UP TOGA scenario.
But it is invisible to the other pilots in the flight deck ... When the PF was full back stick for a thirty seconds period after the aircraft was stalled, neither of the 2 other guys would know that important piece of information. That's what Sullenberger is talking about.

DozyWannabe

1st Nov 2012, 00:27

Once and once only on this issue:

Too bad your references are based on cvr, just not fdr.

DFDR matches CVR. If you are referring to Ray Davis's independent reading of the FDR, he was not experienced in dealing with the new digital models, and got it wrong.

From the document posted by Franzl months ago : http://www.crashdehabsheim.net/Rapport%20Airbus.pdf

Mr. Davis was apparently not aware of the convention (which is apparently unique to France) that requires that the transcripts of forward accelerations are shown with a negative sign. [He is] therefore claiming that in the last seconds the negative acceleration shown in the transcript demonstrates that the aircraft was decelerating and therefore one or both engines were not providing sufficient thrust.

The flight recorders did not stop instantaneously at Habsheim. In the final report produced by the Commission of Inquiry it clearly states that -after the first impact with the trees, the CVR continued to operate for around 1.5 seconds and then stopped. The DFDR continued to operate
for around one second [after impact] then gave incoherent data for around two seconds". The exact cause as to why the recorders stopped almost simultaneously before the aircraft finally came to rest could not be determined. The most probable cause is that the power supply cables of the two recorders broke.

His intention was to disable A/THR but did he do it ?
NO

When he was going to do it at time 12 41 58 he was distracted or interrupted by a landing gear issue.

I realise anecdote is not the plural of data but this supposition is a hell of a stretch. I doubt very much that a human being confidently in charge of a machine will immediately stop what they are doing on the basis of a distraction. For example, if applying the brakes when driving and you see an accident in the opposite lane, you may turn to look, but that does not mean you will stop applying the brakes.

Thirty seconds on a disconnect switch is a long period.

The disable trigger is at 15 seconds though (FCOM DSC-22 30-90 P 5/12).

Dozy does not read French

Not fluently, but my wife does - and I have a dictionary.

Anyway - pointless distraction, this is about AF447, not AF296 (which I'm sure would be more than welcome on the AH&N forum if you've been having trouble starting a thread on the subject, CONF...)

CONF iture

1st Nov 2012, 03:44

The disable trigger is at 15 seconds though (FCOM DSC-22 30-90 P 5/12)
Dozy, you don't know the Habsheim report but cannot stop commenting on it.
What is true today was not necessarily at that time.
Next time, ask your wife first, she will tell ...

HazelNuts39

1st Nov 2012, 11:50

When the PF was full back stick for a thirty seconds period after the aircraft was stalled, neither of the 2 other guys would know that important piece of information. That's what Sullenberger is talking about. I wonder, did Cpt. Sullenberger really think this through?
Would AF447 have had the same disaster if this cockpit were a Boeing instead of an Airbus?
I think it would have been much less likely to happen on a Boeing, because the control wheels are large, they're obvious, and could hardly have been missed.

The airplane stalled at 02:10:58. Until 02:11:31 the PF's stick is moving so rapidly back and forth that it is hardly possible to interpret what it is doing to the airplane, except by looking at the attitude display. At 02:11:38 the PNF briefly takes the controls. The attitude is then 15 degrees NU, IAS 133 kt, STALL STALL STALL. Does he push the sidestick forward?

The PF's sidestick reached the aft stop at 02:11:41, that is 43 seconds after the airplane stalled. The AoA was then increasing through 35 degrees. The captain returned at 02:11:42.5. The AoA exceeded 41.5 degrees, became NCD and the stall warning stopped at 02:11:45.

If, at that point, the 2 other guys had known "that important piece of information", what would have been their reaction to it?

Would they have been that "extremely purposeful crew with a good comprehension of the situation (that) could have carried out a manoeuvre that would have made it possible to perhaps recover control of the aeroplane."?

BOAC

1st Nov 2012, 12:54

I think that nothing short of my 'boxing glove' firing out of the panel (see aged post) would have helped either pilot. Whether the CPT would have twigged that both yokes back in the stomachs and 10,000fpm down with TOGA was significant is an unknown factor in Air France, it seems. We can only surmise.

Lyman

1st Nov 2012, 13:17

Howdy HazelNuts39

You post: "The PNF's sidestick reached the aft stop at 02:11:41, that is 43 seconds after the airplane stalled. The AoA was then increasing through 35 degrees. The captain returned at 02:11:42.5. The AoA exceeded 41.5 degrees, became NCD and the stall warning stopped at 02:11:45.

If, at that point, the 2 other guys had known "that important piece of information", what would have been their reaction to it?"...Unquote

"that important piece of information"

You are referring to AoA? Or stick placement? They could not have known AoA; and PNF was engaging in full aft stick post STALL, so he was in the weeds with Bonin?

If the PNF held full aft stick post STALL, as you say, then "the two other guys" are in fact just one other guy, the Captain. The Captain has a particularly poor view of the SS. We know the Captain cannot see PF SS, from the CVR. Or if he can see it, he cannot suss its position......"But I have been climbing...."

If what you say is fact, then each of the three have attempted a climb to recover from STALL, the two pilots by stick, and the Captain by command to Bonin: "Climb, then..." "The PNF's sidestick reached the aft stop at 02:11:41, that is 43 seconds after the airplane stalled. The AoA was then increasing through 35 degrees. The captain returned at 02:11:42.5. The AoA exceeded 41.5 degrees, became NCD and the stall warning stopped at 02:11:45.

If, at that point, the 2 other guys had known "that important piece of information", what would have been their reaction to it? "But I have been climbing..."

And they supposedly had instruments?

HazelNuts39

1st Nov 2012, 13:54

Lyman,

thanks for picking up a typographical error. The PF's stick was held at back stop, which was the "important piece of information" missing for the 2 other guys that CONFiture refers to, the PNF and a few seconds later the captain.

Lyman

1st Nov 2012, 14:07

OK dokey....

But we are left with Captain's command to Bonin... "Climb, then...." to which PF replies, "But I have been climbing..."

So even Captain thinks a climb is a good thing to try, knowing they are Nose Up, and descending at 120 knots?

It simply does not compute. Think of it, Captain believes Bonin is inputting ND, and it is not working to lower the Nose? So he commands Nose Up?

Captain, for one, believes there is a control problem? After all, Nose Up quiets the Stall Warn each time. Do two of three pilots believe the controls are broken?

HazelNuts39

1st Nov 2012, 14:47

Lyman,

the exchange you're referring to is about two minutes later, as the airplane passes through FL100. It's Robert who says "climb, climb". The captain replies "no, no, don't climb".

Lyman

1st Nov 2012, 15:11

Sorry, my bad. Robert has seen the instruments, he knows the score, does he mean 'climb' rhetorically? As in, 'we need altitude' ? If Captain takes him as saying: "NOSEUP!", but knows that is not the thing to do, why has Captain not said "NOSEDOWN!" long ago? It is obvious attitude is a disaster, and will kill them, I continue to maintain there is far more discussion than what is releaseed by BEA.

"no, no, don't climb..." fair enough, but not "nose down" ? Essentially.... "maintain" ?

HazelNuts39

1st Nov 2012, 15:33

Lyman,

The pilots express their observations and commands in somewhat imprecise language. For example: Final report 2.1.2.5: The PNF detected the climb based on observation and reasoning (“according to all three you’re climbing”) One of the three is the ISIS which doesn't display vertical speed. So the PNF probably means nose-up attitude, not vertical speed.

Lyman

1st Nov 2012, 15:47

Thanks HN, as ever.

Isn't that exchange earlier, pre Stall? In the initial climb? "You climb, so go down..." ?

At 10k, the PNF wants Nose Up? The Captain wants to maintain? and PF has the stick at full back? What do each believe as to assiete?

The aircraft has been stabilised in Stall for two minutes, and the pilots are what, " thinking " ?

Thanks for your responses, HN.....

camel

1st Nov 2012, 16:16

DW

As you rightly say this thread is about AF 447.

Could you let us all know your opinion on Sully's thoughts and comments in the video posted by Bubbers44...seems to be a deadly silence so far...?

Thank you.

jcjeant

1st Nov 2012, 16:25

I think this accident will never be fully explained
Too many things have happened unlikely (pilots behavior .. mysterious dialogues or difficult to interconnect them or difficult to explain when compared with FDR data)
So far .. pilot error are the end words ...
I hope that such accident never happens in the future (with same or other aircraft) but unfortunately if this should happen again .. maybe some gray areas will be illuminated in a future investigation if new data are available .....

Lonewolf_50

1st Nov 2012, 17:10

I appreciate Sully's points. Particularly his last.

But I find the narrator to be full of crap.

If he had known what Bonin was doing (about 2:48 in)

Of course he knew, or could have known, without any reference to stick position. The Left Seat pilot has an attitude indicator. It is a primary reference instrument for instrument flight. Robert's attitude indicator would show him the nose was up.

DFDR evidence is that the nose was up, and that the attitude indicator for left seat was functioning.

Regardless of the position of side stick, the aircraft's attitude was wrong, and needed to be corrected.

Based on what I have read of the CVR excerpts, he did a few times suggest/direct to Bonin to "go down" or descend based upon the altitude obviously being wrong.

I never understood him to say was "lower your nose, that is why you are climbing when you should not be."

Can't say why that is how it went down, but I am puzzled at why a pilot would not do what I understand to be standard methods to assist the flying pilot with detecting and making corrections to errors or deviations.

How to Fly 101 was sadly missed by a professional pilot, in his role as co-pilot for that leg of the mission. Why that took place is a critical issue, as Sully notes at the very end of the video.
It sems to me to have to do with matters other than cockpit design, even though my preference as a pilot would be a set up like Boeing's. Or BOAC's boxing glove. :ok:

But there are some core issues here that cannot be solved by addressing that, such as

Basic instrument scan.
Basic error detection and correction.
Basic warnings to other pilot when outside of briefed/target performance goals (maintain heading, speed, altitude when in cruise flight).

The narrator cherry picks a bit of the entire sequence of events to present a skewed version of what the issue are. Note: I agree that stick position is most certainly an aid to the non flying pilot of what the pilot is doing.

I find his presentation dishonest and fundamentally flawed, even though he consulted with Sully and got some valid insight from an experienced airline pilot.

BOAC

1st Nov 2012, 18:04

LW - thank you for the support for the glove. (We can, no doubt, expect reams of code now to decide when it springs forth).:)

The thing that none of us can fathom is how PNF completely ignored the climb to a level well above the safe level for the weight. It still puzzles and worries me. Surely it is a fairly basic lesson instilled in crews (and indeed voiced earlier by this same crew) that you CANNOT climb above xxx and continue a safe flight.

This gaping hole in monitoring has not been addressed. This is all before we stalled. Let's (please) forget sidestick, AB control laws etc etc and ask why? We understand the altimeter and v/s were working on PNF's panel. Was he so totally head down in ECAM such that he did NOT watch the shop? Add to the query how could he NOT notice the extreme pitch attitude? It does not gel in my mind. Two experienced and 'competent' trained pilots. I have said before, 'Command' (LHS in this case) calls for one short sharp instruction here, probably as they passed 36000'?? - " Put the nose down" or "I have control". Why was this inhibited?

Lyman

1st Nov 2012, 19:40

BOAC

For what it is worth...."This gaping hole in monitoring has not been addressed. This is all before we stalled. Let's (please) forget sidestick, AB control laws etc etc and ask why?"

I addressed it early on, along with a similar request to focus on the thirty seconds on either side of the cavalry charge. To no avail; it is evidently more interesting to speculate on how to recover from STALL, than how to prevent its entry.

I thought maybe hellish updraft, uncommanded climb (patent), or BEA fraud.

Without the records, in entirety, this accident will always smell of days old fish...

RetiredF4

1st Nov 2012, 19:55

This gaping hole in monitoring has not been addressed. This is all before we stalled. Let's (please) forget sidestick, AB control laws etc etc and ask why? We understand the altimeter and v/s were working on PNF's panel. Was he so totally head down in ECAM such that he did NOT watch the shop? Add to the query how could he NOT notice the extreme pitch attitude? It does not gel in my mind. Two experienced and 'competent' trained pilots. I have said before, 'Command' (LHS in this case) calls for one short sharp instruction here, probably as they passed 36000'?? - " Put the nose down" or "I have control". Why was this inhibited?

I mentioned that before, the answer lies in day to day flying where only minimal load changes are used for pitch changes otherwise the coffee will leave the small little tables. Once the excessive pitch was established there was not enough time left to get the nose down with a gentle maneuver before the airframe ran out of flying speed. This gentle maneuver was present, look at the FDR and there to the normal load factor graph. And the concentration in this early phase was on the roll problem. Selecting TOGA in answer to the second stall warning rendered this gentle nose down / ease off maneuver useless.

The culprit was to get in such a high pitch firsthand after AP disconnect. Only a drastic maneuver would have corrected this pitch timely, and neither PF nor PNF saw the necessity for it and therefore were not prepared to execute it.

HazelNuts39

1st Nov 2012, 20:21

The culprit was to get in such a high pitch firsthand after AP disconnect. Only a drstic maneuver would have corrected this pitch timly, and neither PF nor PNF saw the necessity for it and therefore were not prepared to execute it. Could you please elaborate, because I don't understand what you are saying. Are you referring to the first, rather gentle pull-up (1 deg/sec) immediately after A/P disconnect, that was partially corrected before 02:10:49, or to the second that pulled the airplane in the stall warning 2 and then stall?

RetiredF4

1st Nov 2012, 21:05

@ HN
The first initial pullup from AP disconnect until 02:10:31
- max g 1.6, pitch 12°, climb rate increase up to 7.000 fpm
-
The try to reduce the pitch from 02:10:32 until 02:10:56
-g overall below +1 g, minimum around + .5g, pitch reduction lowest + 6° , climbrate reduction to 1.100 fpm

TOGA at 02:10:56 after SW2:
-pitch increase to +17,9° within 11 sec, climbrate only slight increase to 1500 fpm. Stick initially still slightly nose down increasing to tendency up.

The initial pullup chewed up the energy, brought the airframe in a nose high attitude, started the climb to altitude not sustainable and was not corrected agrssively enough, although the normal load factor shows up tp +.55 g´s, which is quite a heavy felt unload.

Hope that answers your question.

HazelNuts39

1st Nov 2012, 22:00

@RF4,

Thx for the explanation. Reducing the RoC from 7000 to 1100 fpm in 24 seconds corresponds to an average normal loadfactor of 0.87 g. Maintaining that a couple of seconds longer would have avoided the stall. A drastic maneuver?

RetiredF4

1st Nov 2012, 22:32

Problem being, that at that point stallwarning Nr. 2 communicated approaching loss of control, which was honored by PF by selecting TOGA, a fatal failure.

A drastic maneuver would have been to unload to at least 0.5g to reduce the pitch faster, thus conserving more energy and gaining less altitude, hereby avoiding SW 2 and thus no TOGA with its negative side effect.

The aircraft ran out of speed before the climb was stopped.

gums

1st Nov 2012, 23:07

Well, BOAC and Retired have it pretty much the way I see the scenario.

Don't like to be brutal but here I go from a diehard single seater and more. And I had over a 1,500 hours as an IP in different kindsa jets, some side by side, some front seat/back seat, and most as a chase pilot flying maybe 30 feet from the nugget in his single seat jet. Multiply those hours by 8 or 9 to equal the "heavy" pilot IP time.

BOAC has expressed my primary concern. How come the experienced pilot failed to hit the other guy on the head ( boxing glove from the left seat)? The CVR indicates a few cautions and words of advice, but not "commanding" verbiage. e.g. "alternate laws", "we're going up, so go back down". "gently" and so forth. BOAC's point about being BZ with ECAM crapola might also be a factor.

Then what Retired says, which I agree with to the nth degree. A 1.6 gee pull is very noticeable, and that comes from a guy that routinely pulled 5, 6 and even 8 gees in less than 1 second. Unloading to a half a gee is also very severe unless you are flying A2A combat.

The immediate pull is what I am most concerned with. The jet was doing O.K. and then the speed sensors went tango uniform. Big deal. Why the pull up? Why the experienced pilot in the left seat doesn't take some action or yell at the nugget?

For one more time, the gee command doesn't need full back stick to keep increasing pitch attitude. A tenth of gee command can raise or lower the nose at a degree or two per second if you aren't at approach speeds. OTOH, when I see full back stick for a minute or two, it scares me. What was the experienced pilot doing then?

I also agree with BOAC WRT the mechanically connected yokes. My A-7 time was chasing a nugget who was in another airplane! No family models. So I used him as a giant attitude indicator and then glanced down to see speed, AoA and so forth. In the Viper family model we had zero feedback from the nugget in the front seat. The sticks did not move more than 1/8 inch in any case. So I watched and tried to figure out what the nugget was doing. Pitch, power ( at least the throttles were mechanically connected and I could see the tach) and attitude. So the Boeing yoke discussion is moot. Only control aspect that bothers me is the "auto throttle" and no visible/tactile movement when it changes the power.

When I first joined this discussion, I had posited the "deep stall" scenario. But looking at the 'bus charts and such, then the pitch moment coeffiecients, I could see the difference with the 'bus and my Viper. No easy way to keep the 'bus in a stall unless you keep pulling back ( THS doesn't help, either) . Our Viper FLCS prevented you from pushing nose down once we exceeded the AoA limit of 30 degrees or so. The horizontal tails were already commanding nose down. And the aero of the 'bus seems super. Little shaking or buffeting that lets you know you are stalled. It's only the descent rate and attitude that doesn't agree. You know, "gee, I have 10 or 15 degrees of pitch and 10,000 feet per minute of descent rate". Duhhhh? And oh yes, " I am holding full back stick".

As with PJ, I shall try to remain away from the discussion. Will check in every now and then, but seems to me that most agree we had a major failure of crew coordination and a belief that the jet would keep them outta trouble.

Clandestino

1st Nov 2012, 23:09

Please explain why the crew of C-GPATcould have suffered from Somatogravic illusion with an acceleration of 3 kts per second, but according to you, the crew of AF 447 could not have.
Impossible? Deceleration was caused by the pull-up, not the other way around. Of course, anyone is entitled to disagree with my notion that cause precedes effect.

A drastic maneuver would have been to unload to at least 0.5g to reduce the pitch faster, thus conserving more energy and gaining less altitude, A330 is not tactical fighter, she doesn't fly anything resembling typical F-4 mission profile, there was no need to gain any altitude.

thereby avoiding SW 2 and thus no TOGA with its negative side effect. What negative side effect of TOGA? Mind you, we are discussing the aeroplane flying at FL350.

The aircraft ran out of speed before the climb was stopped. Right stick went into nose up position as the stall warning was triggered second time, consequently attitude increased to 17.9° peak -see page 62. Eventually, it did stop the climb in the most disorderly manner.

You can't have it more than one wayThis is PPRuNe. Anything goes provided it's delivered politely and respectfully.

RetiredF4

1st Nov 2012, 23:58

@ Clandestino

Do you actual read a post in conjunction with the referenced discussion (why was the pullup not arrested) or do you just look for some words to comment on? Do i write in greek or Kisuaheli?

RetiredQuote:
A drastic maneuver would have been to unload to at least 0.5g to reduce the pitch faster, thus conserving more energy and gaining less altitude,

Clandestino
A330 is not tactical fighter, she doesn't fly anything resembling typical F-4 mission profile, there was no need to gain any altitude.

Did i say anything from being necessary to gain altitude or that A330 flies like a fighter or should do so? Stick to my words and do not lay words in my mouth i didn´t write.

Quote Retired :
thereby avoiding SW 2 and thus no TOGA with its negative side effect.

Clandestino
What negative side effect of TOGA? Mind you, we are discussing the aeroplane flying at FL350.

Imho that it was a major assisting part in changing pitch by 11° in connection wit the NU SS. Do the math, look at the loadfactor charts and come back again to comment. Later on the opposite happened, reduction of power had a noticeable effect on reducing pitch, as you stated yourself in previous posts. And we are not discussing an aeroplane flying at FL350, but one that was just short of falling out of FL350. TOGA might not have that much effect on an aircraft in FL 350 flying already at max speed, but it sure has more effect on an aircraft which is on the way to loose it´s aerodynamic stability due to lack of flying speed.

Quote:
Originally Posted by Retired F4
The aircraft ran out of speed before the climb was stopped.

Clandestino
Right stick went into nose up position as the stall warning was triggered second time, consequently attitude increased to 17.9° peak -see page 62. Eventually, it did stop the climb in the most disorderly manner.

Again, read my post as answer to HN´s question. I´m talking about the time period before stall warning two, when the PF attempted to arrest the climb with (HN computed it) average of .87 g´s, which was not enough. The SW2 sounded before a NU SS input was made again and the aircraft was still in a climb with 1.100 fpm. Would the PF had made his ND inputs more agressive like the assumed .5 g´s, then it would imho have changed the siuation significantly.

CONF iture

2nd Nov 2012, 05:30

If, at that point, the 2 other guys had known "that important piece of information", what would have been their reaction to it?

It is shocking – The message is : Something is very wrong here – It can be a crucial part of the enigma, especially for the Captain who is just entering the game.
The only time you see a yoke in that position is for flight control check during taxi-out.

Would they have been that "extremely purposeful crew with a good comprehension of the situation (that) could have carried out a manoeuvre that would have made it possible to perhaps recover control of the aeroplane."?
Maybe yes maybe no – But what is better ?

A given piece of information for all to grab
The suppression of such piece of information

HazelNuts39

2nd Nov 2012, 08:03

Maybe yes maybe no – But what is better ?You may have noticed that my post was in response to cpt. Sullenberger's opinion that the AF447 disaster "would have been much less likely to happen on a Boeing".

HazelNuts39

2nd Nov 2012, 08:07

Problem being, that at that point stallwarning Nr. 2 communicated approaching loss of control,Not true. The stall warning came 4 seconds after the PF started pulling. If he had maintained the nose-down input that produced 0.85 g there would have been no stall warning and no stall.

rudderrudderrat

2nd Nov 2012, 08:56

Originally Posted by Clandestino
Deceleration was caused by the pull-up, not the other way around. Of course, anyone is entitled to disagree with my notion that cause precedes effect.

As RetiredF4 says "Do you actual read a post in conjunction with the referenced discussion or do you just look for some words to comment on?"

PF initiated the climb to "recover" the apparent 400 feet loss due to Mach correction. That was the cause of the initial climb.

A side effect may have been that he suffered from Somatogravic illusion with an deceleration of 3 kts per second which may explain why he was seeking confirmation. (See Page 90 interim report 2011.)
"Ok. Ok. Ok. I am going back down?" (with a serviceable ADI in front of him) PNF then says "According to the three you’re going up so go back down"
PNF then selects ALT ATT "The ‘AIR DATA’ selector then the ‘ATT/HDG’ selector are positioned on “F/O on 3.

If they are not suffering from some Somatogravic illusion with regards to their attitude, why select ALT ATT?

HazelNuts39

2nd Nov 2012, 09:05

rrr,

IMHO one does not get a somatogravic illusion simply by pitching up.There is no change in the total acceleration perceived, the longitudinal acceleration is equivalent to the change in attitude and flight path. A pendulum suspended from the cockpit ceiling would remain in the same position in the airplane. AIUI, somatogravic illusion is caused by a change in the total acceleration, e.g. by adding thrust or applying brakes.

rudderrudderrat

2nd Nov 2012, 09:25

Hi HazelNuts39,

Please see my post 599 and the report Transportation Safety Board | Home (http://www.tsb.gc.ca/eng/rapports-reports/aviation/2008/a08q0051/a08q0051.asp)

If you calculate their linear acceleration, it is about the same as AF 447's deceleration.

BOAC

2nd Nov 2012, 09:39

IMHO one does not get a somatogravic illusion simply by pitching up......................AIUI, somatogravic illusion is caused by a change in the total acceleration, e.g. by adding thrust or applying brakes. - full motion simulators rely on this to generate the illusion of 'acceleration' by tilting the platform nose up! So, you are correct in that the actual pitch motion does not generate it, but the new attitude achieved (nose up) does.

HazelNuts39

2nd Nov 2012, 09:41

Hi rrr,

I've read that report. It doesn't explain how they did their calculations and I don't have access to reference 52.

HazelNuts39

2nd Nov 2012, 09:59

the actual pitch motion does not generate it, but the new attitude achieved (nose up) does. I do respectfully disagree. The pitch change produces a change in flight path. Once stabilized on the new flight path, lift equals weight and the AoA is the same as it was before, hence the change in pitch equals the change in flight path angle FPA. Without a change of thrust or drag, the change of linear acceleration along the flight path is given by a = g * delta FPA = g * delta pitch (angles in radians).

RetiredF4

2nd Nov 2012, 10:03

Originally Posted by RF4
Problem being, that at that point stallwarning Nr. 2 communicated approaching loss of control,

HN
Not true. The stall warning came 4 seconds after the PF started pulling. If he had maintained the nose-down input that produced 0.85 g there would have been no stall warning and no stall.

It´s not black and white again.

Figure 27 final report (http://www.bea.aero/fr/enquetes/vol.af.447/imageshr/figure.27.jpg)

Figure 28 final report (http://www.bea.aero/fr/enquetes/vol.af.447/imageshr/figure.28.jpg)

The PF never had a steady SS, and main cause for the Stall Warning two was the impending exiting of the flight envelope due to airspeed, altitude and pitch resulting in approaching creitical AOA. The SS NU phase might have initiated it a tad earlier, but imho we dont know the effect of it, as the SS input is not necessarily immidiately transferred to a elevator deflection (FBW) and a elevator deflection does not immidiately tranfer to a flight path change (delay until the aircraft reacts). Additionally at 02:10:45 there was a thrust reduction present, just 4 seconds prior the SW2 sounded. We didn´t talk about the effects of that one jet.

The trend to more NU SS might also have been a side effect of handling the throttles from PF, first the reduction at 02:10:45 and then selecting TOGA at 02:10:56.

But basically what i´m trying to say in regard to BOAC´s initial question was, that i see an early recovery attempt prior SW two (see loadfactor). The recovery attempt was not appropriate to the severity of the initial pitchup and the altitude rise and speed decay could not be stopped quickly enough. When the focus of the PF changed from the SS to power and switching indicators and the SW2 sounded, TOGA and SS position kicked the airframe outside the flight envelope without being noticed by the aircrew.

But again it is my oppinion and not fact, and everybody is entiteled to a different oppinion.

HazelNuts39

2nd Nov 2012, 10:32

RF4,

Look again at the figures you kindly posted. On figure 27 you can see that at 02:10:49 the pitch stabilized at 6 degrees and the PF's sidestick going from push to pull. On figure 28 you see the PF continuing to pull. The response of the airplane is immediate, it starts to pitch up. It is that pitch change that causes the AoA to increase and to exceed the stall warning threshold.

Not shown on these figures, the load factor changes from 0.85 to 1.15 in those 4 seconds.

The thrust levers are moved back to 33° at 02:10:47 and the N1 decrease to 85% in 4 seconds. That may have added a nose-down moment change, but did certainly not contribute to the pitch-up.

The following graph illustrates the drastic maneuver:
http://i.imgur.com/5m36B.gif?1 (http://imgur.com/5m36B)

BOAC

2nd Nov 2012, 11:40

I do respectfully disagree.- and entitled, of course, but way off beam! Perhaps you could tell us how you think a full motion sim produces a sustained feeling of acceleration (or deceleration)? the change in pitch equals the change in flight path angle FPA - remembering, of course, that a sim does not have an 'FPA'.

I would suggest you read up on somatogravic illusions. In this case it its the otolithic membranes that are in play. Skylibrary covers it well in www.skybrary.aero/bookshelf/books/767.ppt (http://www.skybrary.aero/bookshelf/books/767.ppt) - you will see the effect on slide 20.

HazelNuts39

2nd Nov 2012, 12:50

BOAC,

Thanks for the link. Very interesting, and confirms what I thought:

Slide 24: The gravity-inertial acceleration (GIA) is the vector sum of the vector of gravitational acceleration (upward) and all other accelerations.
Slide 25: A somatogravic illusion is a false sensation of body tilt that results from perceiving as vertical the direction of non-vertical gravito-inertial acceleration or force.

The direction of the GIA is the same as that of the pendulum suspended from the cockpit ceiling. Its orientation to the airplane longitudinal axis does not change when the airplane pitches up. Its orientation relative to the pilot's head doesn't change if the pilot doesn't change his position relative to the airplane. To convey the same sensation in a sim, the sim's cab doesn't tilt like the airplane it simulates.

EDIT:: Perhaps we should be talking about somatogyral isnstead of somatogravic illusions.

BOAC

2nd Nov 2012, 13:28

Perhaps we should be talking about somatogyral isnstead of somatogravic illusions. - no - they refer to rotational effects and we are looking primarily at attitude based effects.

Did you see slide 20? The effect of 'head tilt' as they call it - 'nose up' attitude here - which results in a sense of acceleration. Add to that the pressure felt on the back due to the tilt, all of which can cause a sensation of acceleration. I suggest you try to watch a full-motion sim - perhaps the best demonstration would be on the 'landing roll' when the sim adopts an extreme nose-down attitude to produce a deceleration effect where you are pushed forward in your harness..

You cannot just rule out somatogravic illusions in 447. It appears they did not really appreciate the attitude they had, so they could well have felt misleading 'acceleration' effects. I have no idea. I take it you have never experienced 'the leans' or the feeling of pitch induced by rapid acceleration/deceleration without 'normal' visual clues - very powerful illusions and the cause of many accidents..

EMIT

2nd Nov 2012, 13:42

Comparing SIMS to real world is a complicated matter, Hazelnut.

In a SIM, the tilt of the cabin is used to give an ILLUSION of acceleration, which then is confirmed by the instruments: the attitude indicator tells you that you are straight and level, and the airspeed indicator that you are gaining speed: sensation and information all agree.
Apparently all the information is congruent, but actually you are stationary on the ground, sitting in a box with no real outside vision.
If you would sit in the SIM with your eyes closed, your motion sensing system would tell you the truth, that you are tilted backwards. Your cognizant system however, overrides your feeling, because all instruments tell you that you are level. Your feeling then "corrects" itself, it must be an acceleration that it senses (but in the SIM the instruments are lying to you, compared to the real world)

In the cases of somatogravic illusion in actual flight situations, when they lead to an accident, the feeling system overrode the cognizant system. No matter how correctly the instruments displayed that the aircraft was level (or at a normal pitch attitude) and accelerating, the feel system told the pilot that he was pitching up abnormally, to which he instinctively reacted by a push on the control (yoke or stick).
Instead of resetting their feel system to the reality shown on the instruments (which tell the truth, in real aircraft), the accident pilots try to reset the world to their illusions.

The human feel system is relatively coarse: accelerations go unnoticed, when under the detection threshold. Ask any fast jet pilot about close formation flying in IMC: if the leader rolls in roughly (noticable) but rolls out very smoothly (not noticeable), then you will feel as if still in a bank, when actually level again. Do that twice in a row and the wingie will feel as if almost flying upside down. A quick glance at your attitude indicator would instantly reset your internal gimbals (even though you were supposed to never take your eyes of your flightlead, such a quick check inside your own cockpit was what you really needed to do).

In a SIM, the motion system may quit if you maneuver heavily (unusual attitude recovery, or trying to replicate AF447). Just disregard your feeling system and fly the instruments, that is what instrument flying is about.

Of course, in AF447, some instruments did not tell the truth (airspeed), but as said many times before, pitch and power were shown correctly and were ample info to keep airplane safely in the air, be it with slightly less than the usual accuracy of a knot and a foot that us perfectionist always strive for.

BOAC

2nd Nov 2012, 13:54

Just so I do not cause unnecessary obfuscation on this thread - I am NOT suggesting that somatogravic illusion contributed to the accident - I just do not know - I am merely trying to help HN39 understand the phenomenon in view of the comments he/she has placed.

HazelNuts39

2nd Nov 2012, 14:16

BOAC,
on the 'landing roll' when the sim adopts an extreme nose-down attitude to produce a deceleration effect where you are pushed forward in your harness..Right, like I said, applying brakes changes the perceived acceleration (GIA).

EMIT,
Thanks. I know all that.

EDIT::
Imagine a person swinging on a swing, eyes closed, moving rigidly with the swing, ignoring the wind and air resistance, what does he feel? He feels the rotational movement of his body (the somatogyral effect), he feels the GIA changing in magnitude, but the direction of the GIA relative to his body does not change, until you start braking the free movement of the swing. He could be standing upright without falling off.

EDIT2::
You cannot just rule out somatogravic illusions in 447. I am primarily responding to rudderrudderrat's post which dealt with the situation prior to stall. I'm not ruling out somatogravic illusions after the stall due to the dramatic increase of drag resulting from the stall.

BOAC

2nd Nov 2012, 15:42

A somatogravic illusion is a false sensation of body tilt that results from perceiving as vertical the direction of non-vertical gravito-inertial acceleration or force.- if you said "A somatogravic illusion can also be a false sensation of acceleration that results from perceiving as vertical the direction of non-vertical gravito-inertial acceleration or force" we'd be there!

PS A simulator has no wheelbrakes.so "applying brakes changes the perceived acceleration" just cannot happen. How else do you think you can "change the perceived acceleration"?

HazelNuts39

2nd Nov 2012, 15:52

BOAC,

Are you being serious? Applying brakes on a moving airplane after landing changes the perceived acceleration. Since the simulator is stationary and has no wheel brakes, it changes the perceived acceleration by tilting the cab. Is that better?

BOAC

2nd Nov 2012, 16:27

Yes, much better. So you accept that a pitch attitude can produce a sense of acceleration - I began to think from your previous that you didn't.

In relation to "are you serious?" it was your post on the 'landing roll' when the sim adopts an extreme nose-down attitude to produce a deceleration effect where you are pushed forward in your harness.. Right, like I said, applying brakes changes the perceived acceleration (GIA). that made ME wonder and I think it was also
Quote:
Originally Posted by BOAC
the actual pitch motion does not generate it, but the new attitude achieved (nose up) does.

I do respectfully disagree. Why disagree? You have just agreed!

HazelNuts39

2nd Nov 2012, 16:55

So you accept that a pitch attitude can produce a sense of accelerationI've never disputed that, nor have I disputed that somatogravic illusions can occur. What I'm arguing is that the combinations of pitch attitude and longitudinal accelerations that occur in maneuvers at more or less constant total energy (or at quasi-constant rate-of-change of total energy) - e.g. the swing analogy - do not result in somatogravic illusions.

roulishollandais

2nd Nov 2012, 17:16

PNF inaction : I found very strange that crew :

1 former Steward as CPT
1 former Air Traffic Controler as PNF
1 cadet as PF...

As the Controllers are not allowed to "suggest" actions to pilots, and that was his position for some years, when he got a pilot would he have been shy to "suggest" some actions to the PF ? (just an idea)

BOAC

2nd Nov 2012, 17:55

.....not a lot 'odder' than any other explanation we have so far, Rouli. I do, however, feel that the preservation instinct would kick there and over-ride such 'structuring'.

Personally I don't think PNF had a clue what the a/c was doing. I also wonder about the interpretation of the CVR where he says " you are climbing, go down" - did he meant that but had not seen the altimeter going up to oblivion or did he actually mean "your nose is pointing up, put it down"? Until very late there seemed to be no recognition that despite the nose being in 'Climb' mode, the a/c was actually in 'Descent' mode. It appears, unbelievably, that these two, and make that three eventually, believed that a high nose attitude was all you needed to go up.

Clandestino

2nd Nov 2012, 19:16

Did i say anything from being necessary to gain altitude or that A330 flies like a fighter or should do so? Stick to my words and do not lay words in my mouth i didn´t write.
No, but you keep on talking about unloading, maneuvering with respect to Gs and all the other neat stuff that works very well on high power, high drag machines with low aspect ratio swept wings that are used to bomb the :mad: out of the opponent or shoot down his aeroplanes. While some of it are applicable on high power loading, cruise efficient and not very maneuverable machines we use to transport passengers from, A to B, training airline pilots in them would be utterly superfluous as there are already proven and taught procedures to deal with just the stuff that was thrown onto AF447 crew. They did nothing resembling them.

Later on the opposite happened, reduction of power had a noticeable effect on reducing pitch, as you stated yourself in previous posts. Aeroplane was stalled by then. There are significant differences in flying qualities between stalled and unstalled aeroplane.

Imho that it was a major assisting part in changing pitch by 11° in connection wit the NU SS. Do the math, look at the loadfactor charts and come back again to comment. FBW Airbi are flightpath stable in any altn law so the effect of the changing thrust on pitch is automatically canceled and at the computed airspeed at the time stall warning went off the second time, flight controls authority would be pretty sufficient, especially as the difference between TOGA and cruise power at altitude is minimal. Powervise, there is a world of difference between same N1 at cruising level and at sea level - and concomitant pitch moment.

Graph shows right stick to be most of the time in the nose up area, confirming BEAs finding that aeroplane behaved as commanded.

The SW2 sounded before a NU SS input was made again and the aircraft was still in a climb with 1.100 fpm. Would the PF had made his ND inputs more agressive like the assumed .5 g´s, then it would imho have changed the siuation significantly. So "run out of speed" shouldn't be misread as: "...and then stalled" but as "...and then got so slow to activate stall warning that made CM2 pull and consequently stall the aeroplane." I apologize for misunderstanding your post.

PF initiated the climb to "recover" the apparent 400 feet loss due to Mach correction. That was the cause of the initial climbYour interpretation. Incongruent with busting the level by couple of thousand feet subsequently.

A side effect may have been that he suffered from Somatogravic illusion with an deceleration of 3 kts per second which may explain why he was seeking confirmation. I have already posted that successful succumbing to somatogravic illusion requires higher levels of acceleration - such as a TOGA kick. That's what made Air Transat crew succumb to it, not average acceleration. Popping the speedbrakes on the very fast jet might lead to similar Nx values in deceleration sense but I think we have already established that such an equipment was not used on the AF447 route. Now it is possible that mere deceleration of climb can make the pilot succumb to somatogravic illusion and perpetuate the climb into the stall but anyone proving it will open a whole new chapter of aeromedicine.

If they are not suffering from some Somatogravic illusion with regards to their attitude, why select ALT ATT? Suddenly realizing that instruments are not infallible and losing all faith in all of them? Any rational thought abandoning them for good? What difference does it make if they succumbed to this or that illusion anyway?

The PF never had a steady SS...yet the average was nose up.

imho we dont know the effect of it, s the SS input is not necessarily immidiately transferred to a elevator deflection (FBW) and a elevator deflection does not immidiately tranfer to a flight path change (delay until the aircraft reacts). Additionally at 02:10:45 there was a thrust reduction present, just 4 seconds prior the SW2 sounded. We didn´t talk about the effects of that one jet.

IBEAHO:

The aircraft’s movements in the longitudinal axis were primarily due to the inputs by the PF, with the exception of small variations due to the aerology (variations in normal acceleration of about 0.2 g);

There is a picture that goes with it. Also one on the page 97 of the French report (fig 64) - very ugly stuff.

It appears they did not really appreciate the attitude they had, so they could well have felt misleading 'acceleration' effects.
Probably we wouldn't be discussing AF447 at all if it were the only thing they didn't appreciate.

I take it you have never experienced 'the leans' or the feeling of pitch induced by rapid acceleration/deceleration without 'normal' visual clues - very powerful illusions and the cause of many accidents.. ...in military. Civvies have it mostly as pitching down in go-arounds as the low drag, cruise optimized designs just can't produce enough deceleration for it to be really dangerous.

RetiredF4

2nd Nov 2012, 21:50

Clandestino:

No, but you keep on talking about unloading, maneuvering with respect to Gs and all the other neat stuff that works very well on high power, high drag machines with low aspect ratio swept wings that are used to bomb the out of the opponent or shoot down his aeroplanes. While some of it are applicable on high power loading, cruise efficient and not very maneuverable machines we use to transport passengers from, A to B, training airline pilots in them would be utterly superfluous as there are already proven and taught procedures to deal with just the stuff that was thrown onto AF447 crew. They did nothing resembling them.

Sorry that i wrongly assumed, that changing g loading, thus reducing or increasing AOA and thus changing flightpath is understood by civvies and also by yourself. Finally it i nothing less and nothing more than a result orientated change pf pitch and has nothing at all to do with the military, although the used terminology is more present there.

For you and the others who didn´t understand:
unload = reduce g= normal acceleration from present value to a lower desired value, usually performed by a nose down flight control input, using the available pitch steering device (Stick, sidestick yoke, trim....).

You agree, that it can be done also by all aircraft with wings on it and would have been the necessary means to keep AF447 within the flight envelope and prevent the stall, when properly performed?

Clandestino

3rd Nov 2012, 06:39

Old Carthusian

3rd Nov 2012, 08:52

Hello again everybody
Can anyone tell my why after the official report there are 35 pages of debate about what is a fairly clear sequence of events and set of causes? I have no inclination to read these thirty five pages but really gentlemen and ladies the cause is known. We can speculate about the motivations behind the cause but these lie in the area of psychology not technology.

HazelNuts39

3rd Nov 2012, 09:05

... not counting 74 pages in thread no. 9 ...

CONF iture

3rd Nov 2012, 09:49

You may have noticed that my post was in response to cpt. Sullenberger's opinion that the AF447 disaster "would have been much less likely to happen on a Boeing".
I have, but as you was, in a way, questioning his opinion, my reply was to support or justify his opinion.

RetiredF4

3rd Nov 2012, 10:16

Unloading would save the AF447 but it is far from being only possible solution. Other ones: not pulling in the first place, not disregarding the stall warning, returning to assigned altitude instead of merely reducing the RoC from humongous to merely excessive, etc...

Not pulling in the first place would have prevented the the whole event, as would have functioning pitot tubes. It is self explanatory.

Returning to the assigned altitude, there starts the problem, if you refer it to the part after initial pullup. This returniung to the altitude was imho exactly what the PF tried, smooth and easy and no coffee cups on the floor and no passenger complaint. But he f**d up badly in the pullup and a normal return to the assigned altitude like in day to day flying with easy initiation and all doing nicely worked not out as planned. The speed decayed unobserved due to failed pitots and unnoticed due to lack of common sense concerning aerodynamics and energy management near the service ceiling of the aircraft. The necessary recovery action was time critical.
In this situation returning to the assigned altitude has to observe those specifics and the primary focus has to be angle of attack reduction and speed conservation. The normal parameters for changing altitude or regaining altitude like a special pitch change, a special change of vertical speed, a known SS input might not work in the time available.

I referenced the amount of change to the normal load factor value, as that one is documented in the FDR. I´m well aware that afaik neither AOA nor normal loadfactor are readily displayed in the cockpit.

Unloading is the most effective on highly aerobatic, very powerful and draggy designs, such as Su-26 or Su-27.

Unloading can be performed in any aircraft and is done during any approach to stall recovery. On which aircraft it is most effective is of no relevance to the discussion here.

My post has nothing to do with a special maneuver, what i´m saying is that an early recovery atempt before SW2 was made, documented by the normal load factor in the FDR, computed by HN to be +.87 in the average, but that it was not agressive enough.

HazelNuts39

3rd Nov 2012, 10:33

+.87 in the average, but that it was not agressive enoughIt would have been sufficient, had it not been terminated too early. Why the PF reverted to pulling the nose up remains the biggest mystery of all for me. The report mentions the return of the flight director, the fixation on overspeed, training exercises at low altitude ...

P.S. What strikes me in the various 'level bust' incidents, and in the pitchdown of QF72, that pilots react instantly to an overspeed situation, but are remarkably relaxed when the airplane climbs 3000 ft towards its stall ceiling.

rudderrudderrat

3rd Nov 2012, 11:34

Originally posted by Clandestino
I have already posted that successful succumbing to somatogravic illusion requires higher levels of acceleration - such as a TOGA kick.
I know you have. What's your source of information, or is it something you just make up?

Please see slide 24 of Operator s Guide to Human Factors in Aviation (http://www.slideserve.com/micheal/operator-s-guide-to-human-factors-in-aviation) or somatogravic%20illusion.ppt (http://www.blackholes.org.uk/PP/somatogravic%20illusion.ppt)

"The somatogravic illusion of ‘nose-up’ sensation after takeoff and the erroneous correction of the pilot to push the yoke forward has caused more than a dozen airline crashes

An aircraft accelerating from 170 to 200 knots over a period of 10 seconds just after takeoff, generates +0.16 G on the pilot

The GIA is only 1.01 G

The corresponding sensation is 9 degrees ‘nose up’

When no visual cues are present and the instruments are ignored, an unwary pilot might push the nose down and crash."

According to my maths, accelerating from 170 to 200 kts over 10 seconds is about 3 kts/sec.
The graph of AF 447's ground speed shows a deceleration rate of about 3 kts/second during the climb from FL350 to FL 380

If an acceleration can produce a sensation of 9 degs nose up, why can't a similar deceleration produce a sensation of 9 degs nose down?

Originally posted by Clandestino
Now it is possible that mere deceleration of climb can make the pilot succumb to somatogravic illusion and perpetuate the climb into the stall but anyone proving it will open a whole new chapter of aeromedicine.
See Operators Guide to Human Factors in Aviation.

Originally posted by Clandestino
What difference does it make if they succumbed to this or that illusion anyway?
The difference is it may explain why two qualified pilots made those errors that night.

HazelNuts39

3rd Nov 2012, 13:10

Taking its definition literally, a pilot is under somatogravic illusion anytime he is flying on instruments but believing his bodily sensors rather than his instruments. Since that is contrary to basic instrument flying training, there must be some extraordinary combination of circumstances for this to happen. Is a deceleration of 3 kts/sec sufficient explanation by itself, for two qualified pilots at the same time?

If an acceleration can produce a sensation of 9 degs nose up, why can't a similar deceleration produce a sensation of 9 degs nose down?It can, but when it is caused by the attitude being actually 9 degrees nose up, the sensation would be that of level attitude.

Clandestino

3rd Nov 2012, 13:52

I have repeatedly warned against trying to build advanced theories while having no firm grasp on the basics. It was a win-win proposal for me.

Folks listen to me, bandwidth wastage gets reduced.

Folks disregard, I'm kept entertained.

For those unable to take subtle hints: anyone proving somatogravic illusion played a role in AF447, or for that matter that the illusion of pitch down due to deceleration in any airliner incident/accident, would make such a breakthrough that he would stand a good chance of winning both Collier trophy and Nobel for medicine. Good luck with it and don't try to do it with G-CPAT incident, it was pitch-up illusion. Basic aerodynamics folks. Lift to drag. Trust to weight.

Oh and thank you for providing very interesting link, rudderudderrat - the one with very vague and general description of somatogravic illusion during takeoff and landing. Applying lessons "learned" from it to instance of UAS in cruise would have been heavy work, leaning heavily on imagination. Anyway:

An inexperienced pilot may perceive deceleration due to lowering the flaps as steep nose-down sensation....cracked me up. Maybe if one is flying Dauntless and opens split flaps in one go. Airliner flaps are a) not so draggy b) never lowered full in one step. Makes me wonder at what operator
was that presentation aimed.

Can anyone tell my why after the official report there are 35 pages of debate about what is a fairly clear sequence of events and set of causes?It has to do something with human factors. I mean regarding to posters, not the crew.

This returniung to the altitude was imho exactly what the PF tried, smooth and easy and no coffee cups on the floor and no passenger complaint.First, that's not the way it works in the real life because a) pilots are trained to put safety before comfort b) other similar incidents have shown a) is observed in real life for most of the time by most of the crews. Second, CM2 warned FAs about possible turbulence ahead four minutes before UAS, therefore chances of coffee being a factor were nil. Third, calling sidestick movements recorded on FDR smooth and easy is not something I'd do but then it could be my level 2 English.

The necessary recovery action was time critical. True, but it was not even initiated.

In this situation returning to the assigned altitude has to observe those specifics and the primary focus has to be angle of attack reduction and speed conservation.In F-4 Phantom. Is it so hard to accept that airline pilots are not trained in ACM so their procedures, while still working as supposed, are not leaning heavily on maneuvering part? Even if they went to Climb thrust/5° pitch at the apex of their climb, aeroplane would stabilize at alpha slightly above 5° and perform gentle driftdown to 5° alpha ceiling.

It is not as important to know the reason and principles involved in procedures as it is important to perform the procedure timely and precisely when required. Now, I'm not saying that detailed knowledge of aeroplane, HF and air is useless, just that many a pilot had successful and long flying carrier while being oblivious to some basic flying facts.

The normal parameters for changing altitude or regaining altitude like a special pitch change, a special change of vertical speed, a known SS input might not work in the time available.

Here we go again:

The aircraft’s movements in the longitudinal axis were primarily due to the inputs by the PF, with the exception of small variations due to the aerology (variations in normal acceleration of about 0.2 g);

Pushing the stick full forward on Airbus gives you -1G clean (and fast enough, about which there was no doubt when second stall warning went off). That's enough enough. Now watch the ignorant bite on this one.

I´m well aware that afaik neither AOA nor normal loadfactor are readily displayed in the cockpit. Because they are absolutely inessential in transporter! We might install them one day when we go seriously about the business of air combat in A330 but I can't see it happening anytime soon.

Is a deceleration of 3 kts/sec sufficient explanation by itself, for two qualified pilots at the same time? No, but is as convenient to derail discussion as is composite fin of AA587, NDB identifier regarding the AA965, core lock of Pinnacle 3701, or who-knows-what-not at Habsheim. Same stuff on anonymous internet fora every time Caucasian (minus Russians) crew stuffs it up. Lesson from worldwide spread of accidents is there are no American/Chinese/Russian/Somali/Graustarkian aerodynamics or physics and flying does not care a little bit about pilots' cultural background, it's just some cultures are more prone to rejecting the traditional and embracing the pragmatic - essential for aviation. Instead of understanding it, what we have on the PPRuNe is a lot folks mistakenly believing that they know something about aviation and gloat about how their cultural circle has better "safety statistics" than some other one. So then comes AF447 and dreams of immanent aeronautical superiority are shattered and we get thread upon thread of nonsense coming from those wounded by their Aeroweltanschauung suddenly shown to be false.

jcjeant

3rd Nov 2012, 21:45

For those unable to take subtle hints: anyone proving somatogravic illusion played a role in AF447, or for that matter that the illusion of pitch down due to deceleration in any airliner incident/accident, would make such a breakthrough that he would stand a good chance of winning both Collier trophy and Nobel for medicine. Good luck with it and don't try to do it with G-CPAT incident, it was pitch-up illusion. Basic aerodynamics folks. Lift to drag. Trust to weight.
Answer "a la clandestino" (fair enough)
Anyone proving somotogravic illusion not played a role in AF447 would make such a breakthrough that he would stand a good chance of winning both Collier trophy and Nobel for medicine

clandestino
Originally Posted by Retired F4
I´m well aware that afaik neither AOA nor normal loadfactor are readily displayed in the cockpit.
Because they are absolutely inessential in transporter! We might install them one day when we go seriously about the business of air combat in A330 but I can't see it happening anytime soon.
It is certain (for clandestino at least) that AOA is truly one of the less important data
However when this data is outside that prescribed for the airplane ..this airplane become an iron mainly subject to the Newton law ....

DozyWannabe

4th Nov 2012, 05:22

Could you let us all know your opinion on Sully's thoughts and comments in the video posted by Bubbers44...seems to be a deadly silence so far...?

Sorry - missed this.

I'm pretty sure I stated my opinion the first time CONF iture posted that video, which if I recall correctly was along the lines of - he's as welcome to his opinion as anyone, and his feat of flying certainly means that opinion will have clout and I for one am in awe of what he pulled off. Nevertheless, I disagree with aspects of it on the grounds that there have been several instances of pulling into stall (at least one of which involved UAS) where the presence of a linked PFC had no effect on the outcome.

You may well ask who the hell I am to hold such an opinion, and the answer is "nobody". But the fact is that the argument stating linked controls will prevent a situation where one pilot pulls back into a stall and the other does nothing is demonstrably untrue.

RetiredF4

4th Nov 2012, 11:39

Clandestino
I have repeatedly warned against trying to build advanced theories while having no firm grasp on the basics. It was a win-win proposal for me.

Folks listen to me, bandwidth wastage gets reduced.

Folks disregard, I'm kept entertained.

For those unable to take subtle hints:

Your bandwith of self esteem (http://en.wikipedia.org/wiki/Self-esteem) will remain unchallenged.

Originally Posted by Retired F4
This returniung to the altitude was imho exactly what the PF tried, smooth and easy and no coffee cups on the floor and no passenger complaint.

Clandestino
First, that's not the way it works in the real life because a) pilots are trained to put safety before comfort b) other similar incidents have shown a) is observed in real life for most of the time by most of the crews.

New message there, pilots always do what they are trained for? Are they trained to crash too like AF447?

Clandestino
Third, calling sidestick movements recorded on FDR smooth and easy is not something I'd do but then it could be my level 2 English.

That s not what i do and nothing i said. , but what the PF intended to do and was not able to because of lack of manual flying expierience in FL 350 in ALT2B law.

Quote:
Originally Posted by Retired F4
The necessary recovery action was time critical.

Clandestino
True, but it was not even initiated.

Then you have an different explanation for the reduction of V/S, Nz , for the SS being ND until 3 sec. before SW 2 ?

BEA Final report, bolding by me
The PNF’s intervention prompted the PF to apply inputs that reduced the pitch attitude, which had exceeded 10 degrees. Although the PF agreed that the objective should be to lose altitude, his inputs maintained the aeroplane on an ascending flight path. The crossbar then indicated a pitch-up input, which did not stimulate him to make sufficient pitch-down inputs to satisfy the PNF’s request. On his side, the PF checked the position of the thrust levers (“We are in, yeah, we are in climb”) then six seconds later reduced the thrust.
The PNF had noticed the need to stabilise the flight path, and the need for moderate aeroplane handling inputs. He probably considered that the reduction in pitch and the vertical acceleration sensed was a sufficient sign that the PF would correct the flight path to allow him to devote himself once again to identifying the failure.

Clandestino
Even if they went to Climb thrust/5° pitch at the apex of their climb, aeroplane would stabilize at alpha slightly above 5° and perform gentle driftdown to 5° alpha ceiling.

It is not as important to know the reason and principles involved in procedures ............ just that many a pilot had successful and long flying carrier while being oblivious to some basic flying facts.

You are entiteled to contact BEA and tell them your point of view, especially the misuse of the unreliable airspeed procedure which would have worked well after AP-disconnect, as an high altitude approach to stall recovery procedure. Good luck with it.

BEA final report, bolding by me
In the absence of reliable speed indication, an understanding of the physics of high-altitude flying, gained through training in the fundamental principles of energy conversion, equilibriums of forces, and lift and propulsion ceilings, could have considerably helped the pilots to anticipate the rapid deterioration in their situation and to take the appropriate corrective measure in time: initiate a descent.

Clandestino
Pushing the stick full forward on Airbus gives you -1G clean (and fast enough, about which there was no doubt when second stall warning went off). That's enough enough. Now watch the ignorant bite on this one.

As you make yourself an expert in ACM, please note, that -1g (full ND SS) produces nearly the same drag as +2g and would be not suitable to regain energy.

Clandestino
Because they are absolutely inessential in transporter! We might install them one day when we go seriously about the business of air combat in A330 but I can't see it happening anytime soon.

BEA Final report, bolding by me
It is essential in order to ensure flight safety to reduce the angle of attack when a stall is imminent. Only a direct readout of the angle of attack could enable crews to rapidly identify the aerodynamic situation of the aeroplane and take the actions that may be required.
Consequently, the BEA recommends:
- that EASA and the FAA evaluate the relevance of requiring the presence of an angle of attack indicator directly accessible to pilots on board aeroplanes.

Clandestino

4th Nov 2012, 12:37

New message there, pilots always do what they are trained for? Are they trained to crash too like AF447? :ok: Well that's the point! The crew was trained to recognize and deal with UAS, they didn't follow the training. Now that in itself is a moot issue as before any abnormals aeroplane has to be under positive and proper control, which it turned out not to be. AF machines suffered from UAS before, it was the first and only that crashed.

That s not what i do and nothing i said. , but what the PF intended to do and was not able to because of lack of manual flying expierience in FL 350 in ALT2B law. For umpteenth time: this is severe misinterpretation of the report. If aeroplane's attitude was gyrating around some acceptable value, then one would be justified to say that pilot had a problem with manual skils. Both attitude variation and stick positions confirm that CM2 was bent on climbing the aeroplane without understanding the consequence of it and without verbalizing what are his intentions or perception of the situation and that goes against basic airline pilot training anywhere.

Then you have an different explanation for the reduction of V/S, Nz , for the SS being ND until 3 sec. before SW 2 ?Simple. Airbus 330 is not F-4. Proper recovery action is not unloading but achieving stable attitude and power and then recovering the altitude (if affected at all). CM2 never achieved anything like it. He made a half-hearted attempt to reduce climb but even before he achieved anything like useful pitch, he reversed into pulling again into insane attitude for the altitude they were flying at. Insane for A330, not F-4, that is.

You are entiteled to contact BEA and tell them your point of view, especially the misuse of the unreliable airspeed procedure which would have worked well after AP-disconnect, as an high altitude approach to stall recovery procedure. I wasn't discussing stall recovery at all, just UAS. Is there any doubt that stall was brought on by CM2's completely inappropriate reaction? Well, I did warn about need to understand the matter discussed to have meaningful debate.

As you make yourself an expert in ACM, please note, that -1g (full ND SS) produces nearly the same drag as +2g and would be not suitable to regain energy. Airbus 330 is not F-4. It is very low drag, low maneuverable and low powered, compared to Phantom. I referred to fact that means of complying with UAS procedure were readily available. I have already mentioned that a pilot can have a very successful career just by doing as trained and as written in manuals without having a grasp on the basics.

Loss of energy during climb in airliner is not the same as the loss of energy during maneuvering a fighter and same procedures need not be applicable.

Anyway, figure 64 of the French report shows the calculated trajectory of the aeroplane without any crew input, demonstrating that even doing absolutely nothing would lead to much better outcome than what the crew did.

As for investigating authorities, they make recommendations, based on the accident/incident they investigated and are not required to estimate the overall impact of them. That's something for manufacturers and aviation authorities to do (and is reason enough to keep investigating bodies independent). Their response might be acceptance, reject or anything in-between and gets classified by investigators as acceptable or unacceptable. Now, installing the AoA gauge seems to be the way to go to BEA but then EASA might point out that a) other crews reduced AoA in UAS situation when stall warning went off b) thousand upon thousands of civil aeroplanes are flown successfully every day without AoA gauge so the reccomendation is rejected. It is possible that compromise solution will be found with visual stall warning. It is possible recommendation will be accepted, we'll get gauges and new training procedures grafted onto existing ones. We shall see what we shall see.

OK465

4th Nov 2012, 14:07

It's interesting 'hearing' a fighter guy talk about airliners and an airline guy talk about fighters (and I mean that in a complimentary way to both).

When going from a 727 flight in the morning, across town to an F-16 flight in the afternoon, I occasionally had the feeling that I should stop off at a phone-booth and change from Clark Kent to you know who. :)

In absolute terms, they are indeed different worlds, but aviation best practices span them both. :ok:

RetiredF4

4th Nov 2012, 15:37

Originally Posted by Retired F4
Then you have an different explanation for the reduction of V/S, Nz , for the SS being ND until 3 sec. before SW 2 ?
Clandestino
Simple. Airbus 330 is not F-4. Proper recovery action is not unloading but achieving stable attitude and power and then recovering the altitude (if affected at all). CM2 never achieved anything like it. He made a half-hearted attempt to reduce climb but even before he achieved anything like useful pitch, he reversed into pulling again into insane attitude for the altitude they were flying at. Insane for A330, not F-4, that is.

Quit the F4-Thing. I was qquoting BEA (for your convienience again below.

BEA Final report, bolding by me
The PNF’s intervention prompted the PF to apply inputs that reduced the pitch attitude, which had exceeded 10 degrees. Although the PF agreed that the objective should be to lose altitude, his inputs maintained the aeroplane on an ascending flight path. The crossbar then indicated a pitch-up input, which did not stimulate him to make sufficient pitch-down inputs to satisfy the PNF’s request. On his side, the PF checked the position of the thrust levers (“We are in, yeah, we are in climb”) then six seconds later reduced the thrust.
The PNF had noticed the need to stabilise the flight path, and the need for moderate aeroplane handling inputs. He probably considered that the reduction in pitch and the vertical acceleration sensed was a sufficient sign that the PF would correct the flight path to allow him to devote himself once again to identifying the failure.

Clandestino
I wasn't discussing stall recovery at all, just UAS. Is there any doubt that stall was brought on by CM2's completely inappropriate reaction? Well, I did warn about need to understand the matter discussed to have meaningful debate.

That seems to be a permanent problem, that you take out of a discussion what you like and make a comment that suits you. We, or at least that was the beginning of my involvement again, were discussing the time after the initial pitchup until SW2. After the AP disengagement until the initial pullup the UAS procedure would have been appropriate. After the initial pullup we talk per definition about an upset situation. The upset started per Definition with SW1 and lasted until the end of the flight.

Definition of aeroplane upset, Bolding by me
Aerodynamic principles applied to large, swept-wing commercial jet airplanes are similar among all manufacturers, and the recommended techniques for recovering from an upset in an airplane subject to these principles are also compatible. Pilots who understand the conditions of an upset, though such an event is unlikely, will be better prepared to recover from it. The four conditions that generally describe an airplane upset (figure 1) are unintentional:

Pitch attitude more than 25 degrees nose up.
Pitch attitude more than 10 degrees nose down.
Bank angle more than 45 degrees.
Flight within these parameters at airspeeds inappropriate for the conditions.

And from the BEA report, bolding by me
The excessive amplitude of these inputs made them unsuitable and incompatible with the recommended aeroplane handling practices for high altitude flight.

Clandestino
I have already mentioned that a pilot can have a very successful career just by doing as trained and as written in manuals without having a grasp on the basics.

There are those pilots, who had a bad day and lived through it, those who still have that day in front of them, those who never will expierience a bad day, and few who perished like AF447 did. I prefer those pilots, who have the knowledge to handle such a bad day by using knowledge and expierience.

Clandestino
He made a half-hearted attempt to reduce climb ..

By mistake or by what intention? To counter the deviation from assigned altitude, to correct the pitch, to arrest the climb? Or did he do it unintentionally, by chance, or because he forgot that he liked pulling?
It was half hearted or not enough, whatever you call it, and that is exactly what i said and what you needed to comment on with:
Clandestino True, but it was not even initiated.

OK, we agree, that you must be in disagreement, whatever another post says.

Clandestino
Loss of energy during climb in airliner is not the same as the loss of energy during maneuvering a fighter and same procedures need not be applicable.

Again you draw the comparison on a fighter aircraft and you dont have any idea of it. Hitting stall warning with 5 g´s (with 1,6 g´s a fighter is not maneuvering but merely easy turning)) on an fighter during maneuvering is no big deal, relax the g´s and that´s it.

But loss of inapropriate amount of energy or better like in this case the exchange from kinetic energy (speed) into potential energy (altitude) causes the same problems in all aircraft, if the altitude exceeds the service ceiling of the aircraft for the given GW and the given flight circumstances.

Clandestino
Anyway, figure 64 of the French report shows the calculated trajectory of the aeroplane without any crew input, demonstrating that even doing absolutely nothing would lead to much better outcome than what the crew did

We can agree, that we agree on that one.

Clandestino concerning AO
We shall see what we shall see

As they are already available (customer option, BUSS) and needn´t being newly developped, and as there is no known difficult training at the moment for those who bought that option i´d say:

We will see it in the coming aircraft, and some although not all aircraft will be retrofitted.

OK465
It's interesting 'hearing' a fighter guy talk about airliners and an airline guy talk about fighters (and I mean that in a complimentary way to both).

First, thank you Sir.

If you allow me to give your post a personal touch from my POV, than it would look like that: (bolding my insertions)

It's interesting 'hearing' a old but not bold fighter guy talk about airliners and an bold airline guy talk about fighters.

Thank you guys for the audience, it is time to go back lurking and spending my pension.

Clandestino

4th Nov 2012, 19:07

After the AP disengagement until the initial pullup the UAS procedure would have been appropriate. That is entire two seconds. I didn't mean to imply UAS needed to be done after the zoom climb, just that it wouldn't hurt going to memory items even above the practical ceiling. Too keep the aeroplane within the envelope, resorting to UAS procedure is not compulsory but it helps.

After the initial pullup we talk per definition about an upset situation. The upset started per Definition with SW1 and lasted until the end of the flight. Depends on how "unintentional" is understood. CM2 certainly did not intend to stall the aeroplane but it was his actions that stalled her. Pinnacle 3701, Colgan 3407, West Carribean 708, Northwest Orient 6231 and Birgenair 301 were pretty similar in that respect. If pilot doesn't realize his actions are pushing the aeroplane towards the stall, his chances of initiating recovery are nil.

By mistake or by what intention? To counter the deviation from assigned altitude, to correct the pitch, to arrest the climb? Or did he do it unintentionally, by chance, or because he forgot that he liked pulling? Alternate law is still flightpath stable, to reduce pitch one must positively push - that's what fig 27 shows happened. CVR shows that CM2 first suggested it would be good idea to go down, CM1 agreed and prompted him to go down but as the warning fired second time, CM2 changed his mind and pulled again (fig 28). Why? No sensible comment was recorded on CVR.

As they are already available (customer option, BUSS) and needn´t being newly developped, and as there is no known difficult training at the moment for those who bought that option i´d say: BUSS is, strictly speaking, not an AoA gauge but I agree it might turn out to be satisfactory compromise regarding the BEA's recommendation.

HazelNuts39

4th Nov 2012, 22:39

As discussed earlier, the BUSS is no solution for the conditions encountered by AF447. If installed, it can only be made available by switching off the three ADR's, which then remain unavailable for the remainder of the flight. Furthermore, it presents misleading information at altitudes higher than about FL250 because it uses a default stall warning threshold value that does not change with Mach, and (as I understand it) the high speed limit is Vmo but Mmo is not taken into account.

rudderrudderrat

4th Nov 2012, 23:46

Originally posted by Clandestino
Operator's Guide to Human Factors in Aviation, author unknown
Slide 27: Dr Hamish G. MacDougal & Dr Steven Moore.
Dr Hamish G. MacDougall BSc (Hons), PhD (http://www.psych.usyd.edu.au/staff/hamish/)

See Conference Presentations / Peer Reviewed Papers
e.g. 107 "How the Brain Interprets Linear Acceleration During Flight." etc,
Originally posted by Clandestino
...cracked me up..... Makes me wonder at what operator was that presentation aimed.
Priceless!

Lonewolf_50

5th Nov 2012, 15:51

Clandestino, you don't need to be ACM trained to understand, and apply (or be wary of) unloading aerodynamic surfaces, or an aircraft.

Please look up "mast bumping" as it concerns a Huey helicopter. I hope you will be able to reconcile the fact that my instructors, some 30 years ago, were able to convey successfully to me the necessity to NOT unload the head, with no reference whatsoever to EVM or ACM. Also the point of keeping the head loaded while doing NoE maneuvers in low level flying.

In simple, Level 2 English, Unloading the aircraft is done by reducing the G load, and loading the aircraft, as you can imagine, is normally achieved by increasing the G load. This is as true in a Cessna 172 as in a Pitts Special as in a Gulfstream as in Mistubishi Zero, or in a Huey or a Lynx.

For Old Carthusian: I believe Clandestino nailed the reason for the added pages: human factors. :ok:

HazelNuts39

6th Nov 2012, 13:38

The TSB's Finding that the Transat captain PF experienced somatogravic illusion is somewhat questionable. In 1.11.4 Somatogravic Illusion, they write:
(...) When the aircraft is accelerating, the sense organs of the inner ear of the pilot send a signal to the pilot’s brain that is interpreted as tilting backwards instead of accelerating forward. If the aircraft nose is simultaneously raised, the pilot has a very strong sensation of climbing. The illusion of false climb tends to lead the pilot to lower the nose and descend. The aircraft then accelerates and the illusion can intensify.That is o.k., but doesn't describe what happened in the incident. The airplane attitude started to decrease at about 1440:32 EST, when the airspeed was actually decreasing. At about 1440:44 EST the airplane started to descend. Between about 1440:41 and 1440:48 the airspeed increased by about 33 kt IAS, 30 kt TAS in 7.3 seconds, an acceleration of 0.21 g. Yet their figure 10 shows a perceived attitude that is 35° greater than the real attitude, i.e. corresponding to an acceleration of 0.57 g. Difficult to understand.
http://i.imgur.com/QhPf5.gif

rudderrudderrat

6th Nov 2012, 15:22

Hi HN39,

I agree it doesn't match very well. Some of the graphs seem to have slipped by almost 5 seconds.

If we assume the graphs have not been superimposed correctly, and that the greatest illusion of pitch was caused during the fastest acceleration, then between 19:40:42 and 19:40:47 the speed increased from 200 to 240kts. i.e. 40 kts in 5 secs or 8kts per second (0.41g)
ArcTAN 0.41/1 = about +22 degs GIA

When the real pitch and perceived pitch matched at 13 degs (shown as 5 seconds before the start of the acceleration), then the Somatogravic illusion of + 22 degs would make the perceived attitude as 35 degs.

HazelNuts39

6th Nov 2012, 15:56

Hi rudderrudderrat,

The report states:
At about 1440:44, at the end of the climb, the perceived attitude reached greater than 30° whereas the actual attitude was about -3°.Appendix 1 states:

Time ......... IAS ..... pitch

19:40:40.9 ... 197.5 ... 8.5
19:40:44.1 ... 208.9 ... -2.3
19:40:48.3 ... 230.3 ... -2
19:40:52.1 ... 241.9 ... -0.06

rudderrudderrat

6th Nov 2012, 16:03

Hi HN39,

I've been trying for ages to get the words and the picture to say the same, but the closest I've come is +22 degs with the accelerations shown.

HazelNuts39

6th Nov 2012, 16:09

Hi rudderrudderrat,

You may have noted that my purple line shows the perceived attitude according to Appendix 1.

EDIT::
I've been trying for ages to get the words and the picture to say the sameBut you don't question their opinion about the rôle of somatogravic illusion in this incident?

rudderrudderrat

6th Nov 2012, 18:16

Hi HN39,
But you don't question their opinion about the rôle of somatogravic illusion in this incident?
The effect is very well documented, e.g. see http://www.faa.gov/library/manuals/aviation/instrument_flying_handbook/media/FAA-H-8083-15A%20-%20Chapter%2001.pdf Page 1-6.

The Incident Investigators concluded the crew suffered somatogravic illusion. The crew survived and explained their reason's for their actions. I simply can't verify the same value, so why would I question their opinion?

Lonewolf_50

7th Nov 2012, 12:46

When the aircraft is accelerating, the sense organs of the inner ear of the pilot send a signal to the pilot’s brain that is interpreted as tilting backwards instead of accelerating forward. If the aircraft nose is simultaneously raised, the pilot has a very strong sensation of climbing. The illusion of false climb tends to lead the pilot to lower the nose and descend. The aircraft then accelerates and the illusion can intensify.

This is part of the reason why one is taught a thing called instrument flying.

gums

7th Nov 2012, 20:24

Good flamefest, but I liked Okie's observation and the input from our rotorhead Wolf.

Seems to this old and not so bold fighter type that 99% of everything ever capable of sustaining flight obeys the same rules, gliders included.

- It's damned hard to stay in a stall at zero gee.
- Zero gee reduces induced drag and allows your thrust to have an effect on your speed.
- Forget all the somatogravic illusion crapola. We were all trained and routinely flew IFR when our inner ear sensors and butt told us we were inverted or in a left turn or..... I would submit to this august body of experts that the fighter types had to overcome the physiological stuff more frequently than most of the heavy pilots.
- Jiminy Cricket can suggest that you lower the nose, but the other guy has to do so and not continue an unreasonable stick input. So crew coordination and a clear chain of command comes into play, ya think?

WRT to Okie's observation: I was priveleged to check out dozens of USAF Reserve and Guard pilots that had a day job flying heavies. Think Vipers and Sluf's. I had zero problems when they came outta that telephone booth wearing their cape and then we briefed and flew an ACM or ground attack mission. I always thot that they would be the ones I wanted to fly with seated back in row 26B when something bad happened. So salute to them.

WRT to Wolf's observation: Yep, those rotors are simply moving wings and behave just like the ones that don't move. Only biggie is unloading those suckers unless you were in one of those "rigid rotor" types we tested years ago.

Back to the peanut gallery...

HazelNuts39

8th Nov 2012, 14:15

In post #710 I ok'd following quote from a TSB incident report:
When the aircraft is accelerating, the sense organs of the inner ear of the pilot send a signal to the pilot’s brain that is interpreted as tilting backwards instead of accelerating forward. If the aircraft nose is simultaneously raised, the pilot has a very strong sensation of climbing. The illusion of false climb tends to lead the pilot to lower the nose and descend. The aircraft then accelerates and the illusion can intensify. Thinking about it further, I felt I ought to correct that in the interest of an understanding of the flight mechanical aspects of the phenomenon.

Actually only the first sentence is entirely correct. The second sentence is sensorially correct during acceleration on the runway, although it is perhaps somewhat unlikely that it would cause a strong sensation of climbing in an experienced pilot. However, when the aircraft nose is raised in flight, the airplane will actually start climbing and the acceleration will reduce. The reduction of acceleration tilts the perceived attitude forward by the same amount as the real pitch change is nose-up. In other words, the somatogravic illusion is then that the pitch attitude has not changed. A similar argument applies in reverse when the nose is pitched down.

Lyman

8th Nov 2012, 14:26

Hi HazelNuts39

Quote..."The reduction of acceleration tilts the perceived attitude forward by the same amount as the real pitch change is nose-up. In other words, the somatogravic illusion is then that the pitch attitude HAS NOT CHANGED. A similar argument applies in reverse when the nose is pitched down."

caps mine......

Certainly that works as an explanation for a pilot to continue his NU input even though he is climbing, and decelerating? pilot has also foregone scan and has lost his binky, the Flight Director, so.......

Too easy?

HazelNuts39

8th Nov 2012, 15:09

Too easy? Yes, a pilot knows that he cannot trust his senses to determine attitude, and must use his attitude indicator instead.

Lyman

8th Nov 2012, 15:29

Sounds good....

We discuss here a pilot who demonstrably has lost the "plot", and his partner, who evidently was easily pleased that things were acceptable, in the midst of a wild ascent.

Are you willing to suspend your strict definition of "pilot"? In the interest of entertaining a possibility? Once the climb established, and control was lost (i define upset as three seconds after loss of a/p and at first SW), it becomes difficult to retain textbook definitions, yes?

What manner of 'control' involves the stick venturing to and fro, a constant (net) NU, and Stall Warn bracketing a climb of three thousand feet in restricted airspace?

Can we agree that loss of SA may have at least potentially involved spatial disorientation?

rgds

HazelNuts39

8th Nov 2012, 16:01

Hi Lyman,

How did he manage to control roll if he was not looking at the attitude indicator? How did he determine that he had lost (lateral) control at 02:11:31? How did he manage to maintain 15° NU until he also lost longitudinal control?

Lyman

8th Nov 2012, 16:24

Because he had confused the two axes, as the aircraft had taught him to, in the thirty seconds it took to kill them all? Have you never fixated on one cue, ignored another? Believed one, and not another? Always trusted dials and completely eliminated sensory? I think he fixed on Roll.

Isn't it clear that whatever he saw v/v Pitch, he pulled anyway? Aren't we looking for reasons to explain this lapse?

This is my point. In AL2b the aircraft behaves schizophrenically, by definition. It required a skill that this pilot had not only not practiced, but may not even have been aware of. Machinbird has explained this, and his comments are instructive. I think Roll had PF totally consumed, so by inferring that he saw AI and "should have" mastered AOA, is presumptive. This flight was lost in the first fifteen seconds, and simply by degrading into a Roll mode that demanded the complete attention of both pilots, such that they lost the awareness of flight path that may have saved them.

No one needs 'twitchy', not in those circumstances....

HazelNuts39

8th Nov 2012, 17:08

Hi Lyman,

You don't address my third question: How did he manage to maintain 15° NU until he also lost longitudinal control?

Lyman

8th Nov 2012, 17:53

'Maintain' 15 degrees suggests he could suss attitude, and that 15 was what he wanted. That also happened post Roll issues, no? Given that he may have selected TOGA, is it possible he was comfortable with a) 15 is acceptable, the a/c is Stall protected, or b) he was flying "g pants".

Maintain is the key word, for it suggests that however he sussed the flight path, his Pitch was 'appropriate', in his opinion. He also may not have been aware of the value.

rudderrudderrat

8th Nov 2012, 18:02

Hi HazelNuts39,
How did he manage to maintain 15° NU until he also lost longitudinal control?
Probably by following these erroneous FD commands.

Time FD MODE
2 h 10 min 08 ALT CRZ HDG
2 h 10 min 08 - 17
2 h 10 min 17 - 21 ALT CRZ * HDG
2 h 10 min 21 - 26
2 h 10 min 26 - 36 V/S +6000 HDG
2 h 10 min 36 - 42
2 h 10 min 42 - 43 V/S +1400 HDG
2 h 10 min 43 - 47
2 h 10 min 47 - 2 h 11 min 40 V/S +1400 HDG
2 h 11 min 40 - 2 h 12 min 52
2 h 12 min 52 - 2 h 12 min 58 V/S +1400 HDG
2 h 12 min 58 - 2 h 13 min 57
2 h 13 min 57 - 2 h 13 min 58 Not recorded- period of associated
parameter sampling insufficient
2 h 13 min 58 s - end of flight
See Page 95 Final report.

Page 198 Conclusions:
"The Flight Directors did not disconnect.
The crossbars disappeared and then re-appeared on several occasions, changing mode several times."

mm43

8th Nov 2012, 18:03

The previous few posts have highlighted IMO the single minded focus the PF had in over-controlling the roll (PIO) at the expense of paying any attention to pitch attitude, vertical speed or altitude. At the back of his mind was his initial introduction to all the good things associated with Airbus FBW, i.e.

In Normal Law it is a protected aircraft with three thresholds incorporated in the protection:

Alpha Prot(ection), which is the maximum attainable stick-free AOA. The auto-trim stops there because there is no valid reason to fly at such a low speed for a lengthy period of time; the speed brakes, if extended, retract automatically.
Alpha floor, which is the AOA where engine thrust increases to TOGA even with auto-thrust selected off.
Alpha max, which is the maximum attainable AOA with the side stick held fully back.

It took 18 odd seconds for the PNF to announce (I suspect rather quietly), "ALT LAW, protections lost". During that time the PF had just assumed that provided he kept the SS back, the longitudinal stuff would look after itself. It didn't, and with less than 50 seconds of the flight remaining, his hallelujah announcement, "But I’ve been at maxi nose-up for a while", kind of says it all.

None of the above excuses the lack of CRM or lack of reference to the QRH, when it was patently obvious that they knew they "had lost the speeds".

HazelNuts39

8th Nov 2012, 19:32

Just another question that occurred to me, to long-range wide-body pilots in particular:

Shortly before A/P disconnect, the CVR recorded this exchange:

2 h 07 min 01 (PF): See, we’re really on the edge of the layer (and under the squall)
2 h 07 min 05 (PF): I mean I’m sure that with three six zero no standard would be good, we’d be ok eh (j’veux dire je suis sûr qu’avec un trois six zéro non standard on serait bon, on serait pas mal hein)
2 h 08 min 03 (PNF): Don’t you maybe want to go to the left a bit?

At about 2 h 10 min 26 the airplane was climbing through FL360.

Could the PF have been looking outside and, aquiring some visual references, attempted to fly by those?

Lyman

8th Nov 2012, 19:51

mm43, hiya....

I think that "50 seconds of the flight remaining, his hallelujah announcement, "But I’ve been at maxi nose-up for a while", kind of says it all."

Was a directed response to a request (urgent?) to climb. As such, PF tips his mind set, and it is damning. He is unwittingly saying that keeping the stick full back has not resulted in....a climb. Which means that he thinks it should, though obviously it has NOT. It also (parenthetically) shows us that all three, AT THIS POINT, do not know what is happening. Sorry, they know WHAT, they do not know HOW.

HazelNuts39

Are there any widebody Captains still here? Because I am tempted to ask who in the world would fly visual here? Aren't they discussing Radar returns?

HazelNuts39

8th Nov 2012, 20:34

Lyman,

He is unwittingly saying that keeping the stick full back has not resulted in....a climb. Which means that he thinks it should, though obviously it has NOT.

Good analysis!:ok:

mm43

8th Nov 2012, 20:48

HN39; Lyman;

I agree with that "good analysis".

It doesn't quite explain why keeping the SS back on approach to the stall with SW echoing in his ears, seems to have worked for him.:\

A lesson quickly learned and acted upon again when the SW returned - but in NCD mode.:eek:

Andy24

30th Dec 2012, 09:10

As part of my airline's recurrent simulator training, we have been asked to simulate the Air France incident. In order to practice the 'Startle Effect' (and in order to avoid the pilots knowing what is going to happen next)it has been left to the discretion of the instructor on how to simulate this in the sim.

I have some ideas in mind ( Volcanic ash encounter and blocked pitos)however would appreciate any feedback from fellow TRI's.

Lyman

30th Dec 2012, 16:16

mm43

"It doesn't quite explain why keeping the SS back on approach to the stall with SW echoing in his ears, seems to have worked for him."

And it cannot, because he is unaware of his altitude. He cannot have been, given the discussion just prior re: temps. It is ironic how the conclusions are in, and present the fantastic as normal, and reality as bizarre..... It is in the nature of directed thought and propaganda, however....

May we hear the CVR?

Thought not. Although one hopes the complete data will be provided to NTSB and FAA. If it is, it will be demanded via FOIA....

Patience.

DozyWannabe

30th Dec 2012, 17:48

I have some ideas in mind ( Volcanic ash encounter and blocked pitos)however would appreciate any feedback from fellow TRI's.

Technically speaking, the TRE in our sim experiments simply failed 2 ADRs in turbulent conditions and triggered a brief thrust asymmetry to simulate the initial roll. The narrative aspect will likely be at the TRE's discretion.

RR_NDB

1st Jan 2013, 18:29

Bear,

May we hear the CVR?

:mad:

roulishollandais

2nd Jan 2013, 02:09

@Andy24
Is it possible to get a little more about your experience?
Which UAS procedure have you used, How much initial pitch did you use, Did you simulate the LOC? Which airline? Which Sim?
Thanks

PJ2

2nd Jan 2013, 06:39

HN39;

Re, "Could the PF have been looking outside and, aquiring some visual references, attempted to fly by those?",

Almost certainly no, he's not flying or attempting to fly clear of cloud by means of visual references. Reasons: a) instruments, not visual cues would be the primary guidance; b) too dark, (no moon) to see the tops, c) even with a moon it is very difficult to judge height of cloud in front...it would be by chance that cloud would be avoided, d) it's just never done, (as in, it is not considered a viable, legitimate manoeuvre nor is it trained); e) change of altitude or track is never done without an ATC clearance. The pilot-in-command of an aircraft an deviate from an ATC clearance in an emergency where the safety of the flight is at immediate and clear risk. As you know, it is my opinion that the loss of airspeed information and the degradation to manual flight is not an emergency.

Lyman;

"Aren't they discussing Radar returns?"

Yes, almost certainly that is what is being discussed. The conversation I "hear" is just what I would have heard in my own cockpit...very ordinary, very operational...normal.

It is extremely rare that the actual CVR is released. Not even the FOIA will do this.

Usually it is notions like "the public interest" that would cause a consideration to do so and even then it would be heavily restricted and "in-camera" in the court so ruling with only the participants absolutely required by the process.

alogobotur

20th Feb 2013, 14:49

Hello to all of you, I need one info.

Does anybody have the AF447 book by J.P.Otelli?

If yes, can you tell me is there an english edition or just in French?

Thank you.

roulishollandais

21st Feb 2013, 14:55

BEA report is better in any case

Lonewolf_50

21st Feb 2013, 15:00

Lyman:
Can we agree that loss of SA may have at least potentially involved spatial disorientation?
Maybe. It depends on what you mean by spatial disorientation.

You can have spatial disorientation without any "feel induced" disorientation playing a part, a common affliction in a non-motion simulators. It isn't hard to wind up massively spatially disoriented (where you are in the air and what you are doing versus where you think you are in the air and what you are doing) by having a lousy instrument scan and a bit of a ham fist. I offer myself and my first few instrument navigation sims during flight training as Exhibit A. I think the term "utterly fargin' lost" (or words to that effect) crossed my sim instructors lips at least once. Weak/poor instrument scan and possibly rough hands look to have been part of this crew's problem.

Back to your question.

I suggest that between time zero and time five seconds of this event (pitot data deemed bad and all three rejected by aircraft systems) SA itself was partial to begin with.

Spatial disorientation loss, or at least impairment, need not have been in the "feel" domain at all. Over the past years on this topic, it has been my estimation that an initial "scan impairment" was exacerbated by the mental effort being expended upon "what's it doing now," which takes you back to some fundamental systems knowldege and training issues, CRM and systems trouble shooting methods. Won't repeat them here.

Based on what can be put together after the fact by looking at the record of outcomes (pilot actions with controls and aircraft performance), the degree of SA retained remained at best partial
-- one cue being as you mentioned, rate of descent and the attendant cue of decreasing numbers on the altimeter seem not to have registered --
and I'll even assert that SA decreased as the time moved forward from zero to impact.

In shorter terms, the crew started behind the aircraft, and got further behind as the event progressed.

This in turn leads me back to both upset and "out of control flight." Out of control flight is more or less the situation in which you make certain inputs to the controls, expecting response A, but you get response B (or perhaps no response at all).

You don't have to be stalled to be out of control.

In one fixed wing aircraft I am familiar with, you can be in a spiral (high roll rate/rotation descent) with symptoms similar to but not the same as a spin (which begins in a stall and gyrates as the plane falls).

If you make control input A, anti-spin control inputs, what you won't get is a recovery from a spin (nor the actual spiral) since you aren't stalled in the first place. What you'll get is response B which is that the plane stays in the spiral until you either hit the ground or you figure out what is actually happening and put in control input B, which would be recovery from a spiral and then fly away.

Until you recoginze what the plane is doing (Situational Awareness at its most basic) your inputs may not yield the outcome you expect, nor the one you desire.

Because the flying pilot believed that the plane was still flying (SW noise and other inputs notwithstanding), he made contol input A, kept making control input A even after a few responses to his crew mate on him going up, and he kept getting response B.

The "aha moment" of "we are stalled" never arrived.

SA was never achieved in any meaningful way beyong the pilot not flying
-- observing that the protections had been lost
-- offering corrections to PF in re "stop going up" that are taken form the CVR.

Because this was a crew, I have to assess the SA of the CREW, as well as individual SA of each pilot who made up the crew.

The sum of their SA was most certainly NOT greater than the two parts. :( The outputs don't suggest either got vertigo, but "disorientation" in terms not "seeing" what their primary flight instruments were showing them is a rather obvious post mortem finding.

Respectfully asserted to those involved in the discussion at this point:
IMO, somatogravatic illusion is a red herring in this particular case.

PJ2

21st Feb 2013, 16:20

Lonewolf_50;
IMO, somatogravatic illusion is a red herring in this particular case. I agree.

Of more importance, and to Lyman's observation of the crew's comment regarding having been "nose-up 'for a while' ", the inability on the part of all three crew members to assess as a stalled condition the high rate of descent which could not be arrested by pitching the nose up is, (as well as the absence of effective CRM and the lack of SOPs), set the pathway to this accident.

gums

21st Feb 2013, 17:05

Gotta go with PJ2. Wolf and Lyman and others......

the inability on the part of all three crew members to assess as a stalled condition the high rate of descent which could not be arrested by pitching the nose up is, (as well as the absence of effective CRM and the lack of SOPs), set the pathway to this accident.

I have previously praised the aero characteristics of plane that made a stall so benign. Many planes would have been rocking/shuddering or even having uncontrollable roll. Then there's the attitude that " I can't stall this plane", not appreciating the reversion laws and such. Hence the comment about having kept the nose up for such a long time to no effect.

Besides that, what bothers me most is the initial reaction and initial control inputs. Why not just "hold what you have'? So the flight directors may have provided bad cues and the crew blindly followed them.

I, too, would appreciate a post from Andy as to the sim ride using the AF447 initial conditions. Was it set up after the loss of the A/P? Was it set up immediately prior to loss of the/ A/P? How much had Andy read about the whole profile? In other words, did the sim IP not say that this would duplicate AF447 but simply failed some air data inputs to get the A/P to disconnect? and the beat goes on....

AlphaZuluRomeo

21st Feb 2013, 17:13

@ alogobotur: I do.
I have no clue if it's been published in english, but here (http://www.pprune.org/6748867-post1229.html) (and also here (http://www.pprune.org/6889460-post580.html)) are some comments about it I wrote at the time.

I concur with roulishollandais: the final report is better (but was released later). The book is an analysis based on what looks like (smells like, feels like) a leaded early draft of the CVR transcript.

@ Lonewolf_50 re: "IMO, somatogravatic illusion is a red herring in this particular case." ==> :D:D

DozyWannabe

21st Feb 2013, 17:41

I have previously praised the aero characteristics of plane that made a stall so benign. Many planes would have been rocking/shuddering or even having uncontrollable roll.

From what I've been told and given to understand - while the stall characteristics are relatively benign, there would be some noticeable buffeting in the stall regime. The problem here is that in that situation it takes a clear head to recognise the difference between the buffeting caused by stall versus the effects of turbulence the crew had been experiencing and were expecting to continue. The obvious way to differentiate would be the presence of the stall warning at the outset and continuing for about a minute, but for some reason this wasn't heeded.

Correct me if I'm misremembering, but wasn't there a school of thought that had the PF misdiagnosing the buffeting - particularly the unusual airflow noise - as an indication of overspeed (or "crazy speed" as he put it)?

gums

21st Feb 2013, 18:08

Correct, Doze, about the reference to a mach/high speed buffet. I can't read minds, especially those of ghosts, so the comment about "crazy speed" is still puzzling.

I discount confusion about the turbulence, as seems most of use can easily tell the diference between "chop" and an airframe buffet ( high or low speed). My own experience with approach to stall in the bent wing birds is that the buffet/burble/shaking is a lot different than turbulence in a storm or near a storm or even "light chop" you see in clear air when near the tropo boundary or the edge of the jet stream. Departure in the VooDoo was prefaced with noticeable buffet and wing rock. The SLUF also shook and rocked. The Deuce was as smooth as silk and the only thing you felt was a buzz ( could hear it, also). Next thing you knew you had the VVI pegged going down until you released back pressure and moved the stick forward.

and so the saga continues, heh heh

Lonewolf_50

21st Feb 2013, 18:15

Dozy, I recall a few threads ago some detailed discussion on what the PF may have heard, and what may have fed him a false input into his SA via the audio channel. (If that sound registered, why not the cricket chirp of the Stall Warning, one wonders? )

With that considered, the A330 was bopping along at something near to Mach 0.8, which doubtless has a sound signature to it if you are in the cockpit. As the initial climb was underway, might there have been a subtle decrease in that ambient noise? As I have no time in the front seat of an A330 at cruise, I have no idea how noticeable that auditory cue would be for a given pilot, nor how subtle or obvious a change in noise related to the change in speed as the aircraft slows down before the stall.

Would the air flow, once stalled, of the plane falling at somewhere around 10-14,000 feet per minute have the same audible signature? I don't know. I can't recall if anyone had a good answer for that.

But it's somewhat irrelevant, other than as a distraction to the primary task of instrument flying at altitude. To establish SA, the noise is a secondary cue related to the information on the primary flight instruments. (FPV addressed by gums up a few posts). So even though this issue of auditory data input has been raised, we are back to disorientation in the visual domain, in terms of a good (or bad) instrument scan and seeing, as well as grasping, (or not) the information displayed on the primary flight instruments.

I am aware of how attuned most pilots are in the auditory channel. Our ears often tell us of a state change, or alerts us to start looking for indication of a change due to "that doesn't sound right." So I won't poo poo the idea that the audio domain may have contributed to disorientation in this case.

In my experience, a change in the sound of something (often engines, or for the rotary winged bretheren the sound of the rotors changing as well as engines) gets your attention and gets you busy until you either fix what's wrong, or at least satisfy yourself that you know "what doesn't sound right."

The CVR doesn't give us much in terms of any discussion they had along those lines, but that doesn't mean neither pilot was dealing with that. It will remain an unknown.

Chris Scott

21st Feb 2013, 19:03

Quote from gums:
"...what bothers me most is the initial reaction and initial control inputs. Why not just "hold what you have'? So the flight directors may have provided bad cues and the crew blindly followed them."

This is the crux of the matter. What I think we can say beyond reasonable doubt is that the PF cannot have made a conscious decision to climb a significant amount above FL350. That he allowed a sustained climb seems inexplicable.

But one thing still bugs me: that sudden INDICATED loss of 300ft caused by the sudden drop of INDICATED IAS/CAS (my deliberate tautology). Pilots are generally unhappy to find they have lost (or gained) that much height in the cruise. The initial reaction may be to recover it asap, however unnecessary that haste may seem. Could this explain the PF's initial stick movement, if not the magnitude of it? If so, his subsequent preoccupation with roll control in roll-direct, and the startle factor causing him to tense up, may go some way to explaining his apparent inability to recognise his inappropriate pitch-up input, and correct it.

PJ2

21st Feb 2013, 20:40

Hello Chris;
But one thing still bugs me: that sudden INDICATED loss of 300ft caused by the sudden drop of INDICATED IAS/CAS (my deliberate tautology). Pilots are generally unhappy to find they have lost (or gained) that much height in the cruise. The initial reaction may be to recover it asap, however unnecessary that haste may seem. Could this explain the PF's initial stick movement, if not the magnitude of it? If so, his subsequent preoccupation with roll control in roll-direct, and the startle factor causing him to tense up, may go some way to explaining his apparent inability to recognise his inappropriate pitch-up input, and correct it. Yes, I think there is something to that in examining the data in the initial 12 to 14 seconds of the initiating (UAS) event. However, the altitude indication returned to FL350 within that time frame the pitch achieved was 10deg NU and rapidly increasing. The fact that no one who is experienced at flying these transports would maintain or even continue such attitudes and/or control inputs is sufficient I think to indicate a rapid loss of SA in terms of what transport aircraft are like to fly at cruise altitudes/high Mach numbers. A rapid return to nominal pitch attitudes in the first 20, possibly 30 seconds would have begun the stabilization process.

After the loss of energy and the increase of the AoA to about 6deg, the nose would have had to have been lowered say, to 5deg ND or even lower, for an effective initial attempt at recovery.

The air at cruise altitudes is, as we all are aware, very thin and the damping effects much reduced compared to the thicker air say, at FL200 so a long time would be needed to stabilize the airplane at that point.

At that point, the only awareness that would have saved the flight was an awareness that the wing was stalled. For a pilot who never hand-flew and who was raised and trained on auto-flight systems and who would never have seen a pitch attitude of say, -10 or -15deg, pointing the airplane down that far with an-already dramatically high VS would have been extremely challenging, but it was the only way to save the airplane.

It is gratifying to hear of so many changes being quietly implemented in training regimes and re-arranged priorities as a result of this tragic accident. That said, knowing how to fly a jet transport airplane using pitch and power in all flight regimes, normal and abnormal, is absolutely, fundamentally paramount in this business, period. Computers and autoflight are huge safety tools but are high-speed idiots that are dumber than a bag o' hammers when it comes to actually flying an airplane.