In my opinion ... correct Dozy.
The opinion of someone flying ... for some time now and on the thing.

Auto trim
 

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.

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.

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.

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.

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....

And the captain could not tell the PF was pulling up before he made that own admission … What a nice concept Airbus really.

@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.

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

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?

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 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?

What feels natural
 

A good point from Doze:

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.

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.

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.

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 !

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

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

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?

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.

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?)

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

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.)

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.

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.

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.

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.

Far from it.
Owain Glyndwr made very interesting comments 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.
You did not reply ... ?

What does it take to get out of hibernation?

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

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.

I 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.

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".

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.

from PJ2:

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.

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

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.

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.

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.

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 ...

I disagree on that.
It took 35 sec (or is it 15 ?) to move the thrust levers, that's all.

If it was the case the THS would have reach its physical NU stop.
What did stop its operation ?

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.

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

@TTex600, with the greatest respect:
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.

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.

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.:(

"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.

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

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.