Autopilot when airspeed stable
 

This may have been answered before, but in a highly-automated airplane such as this, why did it not occur to PF or PM to re-activate AP when airspeed indications tallied? One assumes that 'pitch and thrust' would be one of the first things the AP would 'try', since that's been identified endlessly as the missing reaction?

Also, how come there was no warning when control input asymmetry of a certain magnitude/duration was observed by the flight management system? That would seem like a sound worth hearing.

Yeah, I'm but a punter, but one with a lot of time paying your salaries, and enough wits about me to comprehend much of this. So ne flamez-vous pas, svp.:=

To me that final conversation and the utter lack of CRM calls into question Air France's pilot training. This was exacerbated by the fact that the control sticks on the Airbus move independently (a feature I always believed created more problems).

At some of my past employers the practice of putting two SIC's in the cockpit on oceanic flights became a common practice for the obvious savings in cost. I had been against it for this very reason, no defined chain of command. Internal evaluation revealed that without a set chain of command CRM degrades to a point that safety of flight is compromised.

We ran into a similar problem when two cruise SIC's couldn't make a decision because one was senior to the company and the other was senior on that aircraft type. Despite this and other evidence about the dangers of not having a PIC present on the flight deck I was told that the company would fly two SIC's until the regulators force them to change that policy. The savings in payroll was too much for the bean counters to pass up.

I hope this accident prompts that change, but I doubt it will. The airline industry has lost much of its responsibility as control of operations is taken from experienced, mandated personnel like the Director of Operations and given to accounting. The regulating bodies do not back up those responsible for safety of flight operations and we get situations like this.

Lyman,
It seems to me that, by somehow gaining access to the output of both the CVR and FDR, Otelli has stolen a march on the BEA. I doubt that the BEA's final report will provide much that has not already been reported by Otelli.

Airbus A/P doesn't have attitude hold mode and it does not command thrust.

There is the aural warning when both sticks are out of neutral at the same time. Recorded at 2:13:03.

Consider yourself flamed.

CRM is useless when pilots lack resources of their own to manage.

Air France pilots have previously successfully negotiated loss of all airspeed in A330s.

As long as anyone claiming independent sticks on Bus are problem does not support the claim with some verifiable research, I'll consider such utterances unreliable & irrelevant.

As long as anyone claiming independent sticks on Bus are not problem does not support the claim with some verifiable research, I'll consider such utterances unreliable & irrelevant.
All happy :ok:

@Clandestino

What resources did these pilots lack? Their airspeed indication? I didn't realize you were suppose to disregard CRM when the aircraft encounters an instrumentation malfunction. My opinion based on their interactions is the only resource they lacked was adequate training.

How many times? A good training program is not "good enough", it means that 100% of the time the crew would be able to identify a malfunction and take appropriate action to a satisfactory outcome. Obviously these pilots could not understand what should have been a relatively easy avionics error to "fly through".

Defensive much? I didn't state that as a fact but rather that I believe it, as in it's my opinion. However from the information I've read on AF447 it appears that the independent movement of control sticks was a small contributor to the accident chain and removed one additional opportunity for the accident to be prevented. Had the PNF noticed that the PF had frozen his stick nose up perhaps he would have forced the proper correction. All I can tell you is that there have been times in my career when an uncommanded or unintentional control input has been noticed because the PNF control column moved and was noticed, resulting in proper correction. Mind you this applied primarily to GNE due to lateral errors and rarely pitch problems.

Well, Otelli's publication, the PM article are somewhat verifiable research, in the absence of the still withheld evidence of the same by the BEA (just wonder why ....).

So it really starts being quite some evidence, if one cares to read correctly.

You can all continue to play the ostrich, which only suggests that the brain mass might be equivalent, or there must be some other reason!

But to me the lines in the PM article are horrifyingly evidence enough that independent controls are a distinct disadvantage to coupled ones. The latter would have most probably triggered a very much earlier reaction of the PNF, ......, and most probably have saved the day for those extremely poor pilots.

I'm curious: What kind of reaction?

PNF (as PF) had at a crucial time continuous and then repeated stall alarm in his ears and altitude, attitude and vertical speed indication before his eyes. But he, as hasn't PF, never identified the condition "stall". In my opinion so far, recognizing stall was conditional for adequate measures to "save the day".

So, considering "stall" never made it into the conscious of either member of the crew, what kind of information precisely would PNF have gathered from coupled sidesticks, and what kind of measure one would have to expect as consequence?

read that paragraph taken from the PM article:

Maybe Bonin was so tense that he continuously pulled on the SS without realizing it, who knows, or he was just reacting wrongly. But the fact remains, that Robert did not realize it, at least for too long a time, because the ss is not visible to him and he was rightfully fixed on the PFD. With coupled controls it would have been more easily visible in front of him and furthermore tangible.

Therefore my strong opinion that with coupled controls he would have intervened earlier.

This should be a strong point in favor of coupled controls = feedback.

First and foremost, ability to recognize what was happening.

Keep on not realizing as it is correct thing to do. I have not written it was to be disregarded, what I meant to convey is that it would be useless to use CRM when there is no knowledge or skill to manage.

Valid if the only thing affecting the interaction were training. It is not, therefore: invalid.

At least twice. Interim2 lists only MSNs and dates. It is easy to check who was the operator at the time of the occurence using Airfleets, ATDB or similar but I didn't have the inclination to go through the whole list.

Errr... not quite. There is a thing we call Threat and Error Management that claims we humans are not 100% reliable (quite realistic view, I'd say) but that there are times when we can still work with reduced reliability and yet successfully cope with our eff-ups. Like in cruise.

Yup. WoCL, anyone?

It would be useful if you would retell the relevant part of mr Otelli's publication. Parts that got to the PPRuNe make his book look more similar to snuff porn than serious aviation safety text. Of course, such a selective quoting might lead to extremely biased view on the matter. Or not.

I don't find your ad hominem (or more precisely: ad struthiocamelum) very informative or entertaining.

Since 1988, aeroplanes with uncoupled sticks are allowed to participate in public passenger transport, worldwide. Certifying authorities do not share your concern. What do you know that they don't?

Now that's comforting.
They have certified a lot of aircraft that needed redesign. Think of the DC10.
Just why couldn't they learn? Just why would Airbus be immune to redesign if deficits appear? Just because they flew since 1988? Great argument!

Anyway, I simply flew both systems and that's where my opinion and concern originates.
But then again, what does a simple pilot know ......

And by the way, I didn't want to be entertaining. Metaphors are here to underline a point of view.
Ostrich is quite suitable for some attitudes concerning the apparent deficit in Airbus controls.

Over and out.

OK.....I'm just an "antique" pilot long ago retired, but someone fill me in please on these "uncoupled" side sticks. Just WHICH one has the authority ???

DiCaprio.

No comment re: a/p not reselected, it's in here or TechLog. Post 447, Airbus issued Safety Bulletin: "Do not reconnect Autopilot too quickly post UAS, the aircraft may enter an uncommanded climb."

UAS procedures prior to, and to this day, are a "work in progress" for the Bus.


DC-ATE Sometimes the PIC, sometimes not. Sometimes Both, sometimes neither. It's a proprietary thing, Captain. If you are a BUS flyer, you are permitted to know almost always, especially when the a/c is docile, which is most the time. Rarely, when UPSET, the STICK is mysterious, and no one is permitted to know, lest someone actually have a clue. When one is busy, the other fella is to mind his bidness. It's a French thing.

But Investigation bodies (at least one of them and this is not the BEA of course) share our concern. What do you know they don't ?

DC-ATE, from answers posted previously by those who know, if the two side sticks are sending different messages, and nobody pressed the priority button, the aircraft takes the average.

If one pilot presses the button, that takes priority. If the other one then presses his/hers, it reverts to that one.

Apparently the intention was to enable one to take over if needed, not to resolve a tug of war between two pilots who refuse to agree.

At one point, PNF Robert pressed his and announced that he was taking it. Shortly after, Bonin took it back, with no such announcement, and it stayed that way.

AIUI.

Chris N

ref Post #722, LapSap, surely you must be joking. With all the posts on PPRune about lack of actual hands-on flying, how can anyone ask this question? There are MAJOR players out there who hire non-pilots, train them in Cessnas for a couple hundred hours, let them languish for over a year while learning the books, and then put them on the line in big long-haul wide-body aircraft.

Once on the line, they are forbidden to land in any significant crosswind (and if you are the Captain you would know why), fly MAYBE 3-4 legs a month with the autopilot on by 1500' AGL and off at the marker inbound at which point the plane is basically ballistic.

In 10 years of this great experience they make him a "Commander". If he doesn't screw up 2 years later he is an "Instructor".

Of course, as long as the resulting incidents don't end of as flaming craters, the incidents get buried and you will only see quick blips on here. Any and all negative comments are shouted down by the cheering squad.

See page 7 of this EASA doc. of MAY 2011.
Sounds like some timely concern to me.

http://www.easa.eu.int/rulemaking/do...%202011-09.pdf

"c) The use of side stick controllers together with electronic flight control systems which provide control augmentation and control deflection limiting systems could affect piloting awareness that the aircraft is approaching a control limited flight condition. It may be that return to normal flight condition and/or continuing of safe flight needs a specific crew action. In these circumstances a suitable flight control position annunciation is required to be provided to the crew, unless other existing indications are found adequate or sufficient to prompt that action.
(2) CS 25.777 Cockpit controls
Side stick controller force-deflection characteristics in pitch and roll together with displacement sensitivity and gains need to be evaluated. The intention is to show that normal inputs on one control axis will not cause significant unintentional inputs on the other. Consequently a new paragraph CS 25.777(i) is proposed requiring a suitable assessment."

OK.....thanks for the replies, Lyman - chrisN.
Sure sounds like a STUPID system to me !!

A bit surprised there isn't a drill controlling who is allowed to touch the stick: if you haven't got control, shouldn't your hand be clear and visibly so ?

AIUI (perhaps ATPL’s will put me right if I have it wrong!):

A “drill” is perhaps not quite the right expression, but I’m not sure what is. Under CRM, even a junior pilot is supposed to be able to propose a change from what PIC is doing, or even take over if necessary. Ideally, it never gets to an unresolved argument. But I have seen criticism from ATPLs of a FO who knew that PIC was messing up an approach but felt unable to take over because of his rank. They all died, IIRC. (India? Short runway on top of hill? Went over the end, when FO said go around and PIC did not until too late?)

But what if FO is convinced PIC is doing it wrong, but FO is actually wrong?

In the end, the commander is paid to take decisions, although after CRM-following hearing what the other(s) say.

In AF447, commander left the junior FO as PIC, not just PF, and that seems to have inhibited the other FO in spite of his greater experience. When junior FO Bonin took back control, other FO Robert then tried harder to get commander back, and left it to him to sort it out. Which the latter did not in time.

(IMHO, at least partly because he was not properly told what had happened re stall warning, PF holding stick back, no-one pointing out NU attitude combined with low speed and high descent rate = stalled – but that is another aspect, though still a CRM issue AIUI.)

France's Top Aviation Writer on Air France 447
 

Pierre Sparaco, France' s top aviation writer, an Aviation Week correspondent and author of the definitive book on Airbus, has been covering the company from it's inception 40 years ago. He has just published this commentary Aeromorning.com - Pierre Sparaco Chronicles.

An extract from the PM article posted some time ago .....

Amazing Bonin question about St Elmo fire :sad:
In any case from a commercial pilot
No need to have a university education or be a veteran pilot to know what is a St Helmo fire
I wonder more and more questions about the knowledge of Mr Bonin

" Amazing Bonin question about St Elmo fire ".....
Agreed! This is something I learned about in my instrument ground school and SAW during my instrument flight training. To me, this tragedy is very much related to TRAINING.....or lack thereof.....I guess I was just 'lucky' to have a very good primary, instrument, multi and commercial instructor. I know that training is a 'cost'....but where do we draw the line between 'cost' and SAFETY? Or....DO WE?? :ugh:

can someone tell me (an interested slf) how it works with boeing´s 777 and 787 which are fbw as well but have no sidesticks? do both the yokes move the same? can one pilot feel the "force" performed by the other pilot?

(slightly simplified, but along the general layout)


On the modern Boeings the two yokes are interconnected, thus move the same way. Force felt on one side is according to input force from the other. It is done by a so called drive back. This is a artificial replication of the force input to the ACEs (actuator control electronics) by the pilots.
The ACEs transmit the input to the PFCs (primary flight computers) who then process it and send it back to the ACEs who in turn actuate the hydraulics for the flight control surfaces.
If the input sensed by the PFCs exceeds the programmed parameters of the envelope or protection, the PFCs increase the necessary force up to not executing the commands. However, if the pilot then increases his own input force above a certain value, the PFCs give up and say: "You want it, you get it" and the input is routed directly to the ACEs for execution.

This latter function is the so called soft protection, as opposed to the hard protection of the Airbus that does not allow override of the protections. Only if 3 of the 5 Airbus computers (2 Prims and 1 Sec) are switched off from the overhead panel, the system goes into direct law and then allows unprocessed input.

sf25 - can someone tell me (an interested slf) how it works with boeing´s 777 and 787 which are fbw as well but have no sidesticks? do both the yokes move the same? can one pilot feel the "force" performed by the other pilot?


777 works like every other airplane. The yokes move together. It is visually obvious what inputs the flying pilot is doing.

Shy talk, - “The issue with the sidestick is important.”
Not necessarily as you infer. An aircraft’s response to control input is the combined effects of stick and trim, with the latter providing a significant, perhaps dominant effect. You can compare this with previous accidents / incidents where conventional aircraft suffered upsets due to incorrect trim position; there are several involving go around.

A difference between conventional and sidestick is the trim force. With conventional aircraft an out of trim situation might be detected by an abnormal force, and many pilots take this as an indication of the aircraft position / motion, which is not always true – a lazy, inferred assessment of the control situation.
With a side stick (without feedback), there is no trim force, thus an alternative method of checking trim state is required – look at the trim wheel, check trim indications.

This is not an issue of one system being better than another, it’s that they are different, but the industry has grown up with a force system and this provides a general understanding of the norm.
In normal and those abnormal situations which had been considered, the sidestick system is quite adequate and may have safety and workload advantages.
With AF447 the particular situation was apparently unforeseen, the trim functioned as designed, but together with the surprise and complexity of overall situation the crew had difficulty in determining the situation.
The situation was novel; it required time, knowledge, and reasoned assessment (and reassessment). It appears that these aspects either ran out or did not occur.

Re coupled sticks; it could be incorrect to accept that stick position, coupled or not represents what the aircraft is doing. Checking, monitoring, and establishing the true situation requires looking at the output of control systems – what the aircraft is actually doing.
This requires assessment of the flight instruments, some of which were not available / accurate in AF447.

About the sidesticks. It is my understanding that Airbus sidestick inputs are taken as requested deviations in control surface positions, and not as states for these positions. That is, when a pilot wants to adjust the attitude of the plane by some finite amount, s/he pulls the SS back/forward a specified amount, AND THEN RELEASES THE SS which then returns to a neutral position. The amount of the initial deflection in the SS is what determines the degree of attitude change. Holding the SS at a deflected position causes continually cumulative control surface inputs in that direction.

Thus, isn't it extraordinary that Bonin kept the SS in a deflected back position? Or is my understanding of how the SS works incorrect?

"This requires assessment of the flight instruments, some of which were not available / accurate in AF447"

As I understand it, at least the standby AI (if not the main AI) was functional.

I would have thought that the sight of a lot of blue might have been a hint that they had a rather excessive NU attitude and that consequently their rapid descent might indicate a stall.

Admittedly the main AI may have been almost obscured by alarm messages but from what I have read the standby AI was working.

But what do I know......?

With more tragic irony than flippancy, I propose a slight redesign of the AB sidesticks: a bamboo stick 12-18" long, tied onto each side with two rubber bands.

And that Airline subsidise and mandate glider and/or microlight hours, say 20/year.

My CTSW will do the pilot held stall thingy, showing 28kts IAS or less on high power, plus a dollop of neg VSI

SeenItAll

Excellent points, but a hard sell, at least here. It is not in the interest of the fanatics to accept exculpatory reasoning (exonerating). The PF did not achieve PITCH plus actual for ten seconds (per BEA: "The aircraft did not immediately climb"). We are all also unaware of what the PF saw on his Panel.

PEI_3721

You do not address the point. This is not about TRIM, nor is it in re: feedback, or anything else. This discussion is about "POSITION" of the stick, and its importance to the PM. Had PNF SEEN THE STICK FULL BACK, he would have sussed the problem........period.

Well again; beating a dead horse; with conventional control columns/wheels, there wouldn't be an accident investigation about AF447.

SeenItAll,

Your understanding is not correct.

I didn't visit this thread for . . . . .months/pages, as I have already made MY mind up (as a Boeing -tractor driver) what may have contributed to this almighty cock-up.
Jumping back in after so long , you are the only post on this page, & you have said it all in a few lines. Thanks for such brevity/accuracy

Second....

PEI

Two things. First, I did not mean for my last comment to be so LOUD. I edited in a ....NO? But forget to send.

Secondly, I mean for all my comments to isolate the first 10-20 seconds of the Manual Flight regime. Once Climbing, the discussion is to me unhelpful.

The conditions are so negatively serendipitous that I believe almost everyone here cannot fathom the challenge. So it galls me that so many here presume to be so skilled that the crash would not have occurred.

Apology One:

PEI: I have read your input on these pages many many times, and I appreciate your point of view. I apologize if my comment, in its shrillness, may have been taken as doubtful of your pov.

Apology Two:

HazelNuts39: I assumed your graph was a reprint of something BEA had produced, not original work based on BEA data. As such, the lack of respect I showed was based erroneously on mistaken genesis.

Mea Culpa. You have my utmost respect for your no nonsense input, and its quality is unassailable.

Amen ! but for the DGAC/Airbus to accept the blatantly obvious, it is also (prohibitively) expensive. . . . . so you & I (and anyone who cares to agree with us) are wrong. . . . OK ? :ugh:

In the first 10 seconds after taking control, the PF wasn't holding full aft stick. his stick movements were between 1/4 and 1/2 aft, while moving full travel left to 3/4 right and letting pitch increase to 11.5 degrees NU.