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-   -   AF447 final crew conversation - Thread No. 1 (https://www.pprune.org/tech-log/466259-af447-final-crew-conversation-thread-no-1-a.html)

1066 30th October 2011 19:16

CONF iture

Certainly with the table stowed the other SS is visible. I'll have do another check with the table out. Not 'til 13 Nov though.
My original check was to do with visibility in a dark flight deck.

kwh 30th October 2011 19:28

You would show whatever the aircraft thought the stick was doing. So if pilot A was pulling back and pilot B was pushing forward, the little glowing dot would indicate whatever the aircraft had picked out of the two inputs and understood. Either pilot would be able to see that they were not the only person making inputs, if the little dot was doing something other than reflect the inputs they knew they were making.

You could perhaps add a red dot overlaid by the white, that showed you what input the aircraft had 'allowed', if a pilot was hauling back on the sidestick for all they were worth and the computer was saying 'no you don't, I'm pushing forward...' for some reason...

lomapaseo 30th October 2011 21:18


Beagle’s view at #527 is a dated and unhelpful view of safety. Even during training and within limits, it might be possible to weed out the less capable pilots, but the process should be based on a deeper understanding of an individual’s capabilities and reasons for poor performance, and not just on a the outcome of a single event.
Nobody said they would be weeded out with just one event. If that were the case they could bypass the sim and go direct to a real test5 aicraft.

Screwing up the sim is a learning process, that's why instructors carry pointer sticks.

It's the lack of learning and/or lesson retention that is the issue

infrequentflyer789 31st October 2011 00:32


Originally Posted by CONF iture (Post 6780002)
As long as you don't further overload the PFD ...
Then which sidetick displacement will you display ?
  1. left
  2. right
  3. sum of both
  4. all these answers

Or none of the above, because they are all completely irrelevant / useless ?

I've watched the side stick vs. yoke debate go round and round on these threads, and come to the conclusion that either I don't understand the controls / laws, or the whole debate is completely missing the point. I can't see that it matters on a bus what size the stick/yoke/whatever is or where it is - and that is not because I think there cannot be a feedback problem, but because I think if there is one, it is elsewhere.

However, I don't think anyone one else has made the point / connection, so maybe I am completely confused.

Perhaps someone who acutally flies the thing can answer the following to clarify:
Assuming a 'bus in normal law, as PNF you scan the current position of PF's controls - be it the sidestick, a hypothetical yoke, or a dot on the pfd, or whatever. You see PF, right now, has "stick" in neutral. What does this tell you about what PF is commanding the a/c to do ? [say pitch axis, is the command to climb, level, descend... that's what you want to know, right ? ]

Capn Bloggs 31st October 2011 01:29


I think it's far more worrying that despite verbally handing control to the PNF twice, the PF continued to make inputs. The concept of a single pilot in control at any given time is a fundamental aspect of the Airbus operating procedure and it should be drilled into cadets and pilots as soon as they start their type rating.

Yes, the fact that the PNF could not see or feel that the PF had not relinquished the controls can be considered a shortcoming of the design, but ultimately the PF should have known that "you have control" means immediate hands-off-the-stick unless or until control is explicitly handed back. Even in the old Chippy I used to fly, if I was physically stronger than my instructor I could have overpowered his inputs - and had I done so and lost control as a result, few would argue that the brute-force aspect of the old cable controls was at fault.
I don't agree with any of that. Sure, the PF may be so confused, or not even hear the command "my controls" to not hand over, but that will be painfully obvious to the new PF had a control column been involved (or indeed a Chippy stick). You will know immediately, even if you can't see his hands on it, because of the resistance to your inputs on the controls. No so with a side stick.


it shouldn't require two dirty great control yokes to fix it - just a little tell-tale on the instrument panel with a crosshair on it and showing the current 'virtual stick position', as familiar to anybody who has ever played a computer flight sim game using a keyboard instead of a joystick.
At night, totally confused, alarms/lights going crazy, buffeting... let's look at the "little telltale on the panel"? This is a cockpit, not an office desk.

iceman50 31st October 2011 02:08

Capn Bloggs

Not true, although I cannot remember if there is a mention of it in the interim report, but you will get an aural and visual indication of "DUAL INPUT" plus if either pilot presses the "RED" button then a "Priority Left/Right" aural and visual indication as well. So you WILL know if there are dual inputs. So the indications are already there.

As for the "telltale" there is one on the ground to show control input but not airborne, it used to be available during lift off and initial climb, but then some "pilots" were incorrectly being "trained" to use it for rotation rather than attitude!!! An interesting Emirates departure from Jo'burg comes to mind. Airbus then removed the indication at nosewheel liftoff.

To confirm for 1066 the sidestick is visible in the A330/A340. The PM in this case did not need to see it, as he knew they were climbing, from his PFD indications, and that nose up inputs were being made, hence his comments.

CONF iture 31st October 2011 02:51


Originally Posted by iceman50
As for the "telltale" there is one on the ground to show control input but not airborne, it used to be available during lift off and initial climb, but then some "pilots" were incorrectly being "trained" to use it for rotation rather than attitude!!! An interesting Emirates departure from Jo'burg comes to mind. Airbus then removed the indication at nosewheel liftoff.

100% sure of all of it or you could be mixed up a bit ... ?

Gretchenfrage 31st October 2011 05:16

Defend the SS as much and as fervently as you want (by the way, I actually liked it if it had drive back). With the yoke however, the last xx years there has never been confusion as to what the buddy next to you was exerting and there has never been a false switch mount.

Airbus has invented these phenomenons.

Now as to how much it has contributed to this accident, it's up to interpretation, but it does not bode away that it might have contributed.

I have learnt from all my instruction and experience, that in aviation operation, and that is what pilots do and engineer should do, you should strive to eliminate each and every hole, even the remotest potential hole, in the Swiss cheese.

By staying in denial, you just disqualify yourself as safety driven professional.

iceman50 31st October 2011 05:33

CONF iture

Absolutely, I see it every time I get airborne.

Gretchenfrage

We are never going to convince you so it does not matter. Please explain all the other stall incidents on A/C that had yokes and still stalled as the PF held it fully back. By you staying on your pet hate of the Airbus you are in denial as well.

Capn Bloggs 31st October 2011 06:29


Originally Posted by Iceman
Capn Bloggs

Not true, although I cannot remember if there is a mention of it in the interim report, but you will get an aural and visual indication of "DUAL INPUT" plus if either pilot presses the "RED" button then a "Priority Left/Right" aural and visual indication as well. So you WILL know if there are dual inputs.

Thanks. I stand corrected, although it is conceivable that those warnings would be lost in the chaos. If the control column isn't moving the way I'm pushing/pulling it, that's going to be the most obvious.

fireflybob 31st October 2011 06:45

So if your aircraft is stalling, how far forward should you move the control column/yoke/sidestick in order to recover?

Gretchenfrage 31st October 2011 07:17


We are never going to convince you so it does not matter. Please explain all the other stall incidents on A/C that had yokes and still stalled as the PF held it fully back. By you staying on your pet hate of the Airbus you are in denial as well.
No, you'll never convince me against common sense and human logic, that's true.
Furthermore I do not hate Airbus, as my comment about preferring a SS to a yoke demonstrates.
I hate everything and everyone that is not willing to concede some error and then apply the appropriate correction.

To reverse the denial reproach is a very common and somewhat childish tool of people who cannot see through a genuine proposal to improve design and increase safety: I have repeatedly said, keep the SS but incorporate a drive-back!

Last but not least, I did not contest your perpetual mentioning of "... mama, mama,but the others crashed too, even with yoke .... ". You are spot on with that, no excuse.
Reread what I effectively said, namely that we should all strive to improve design and safety without any taboos. With the SS there has come some new errors. They need to be tackled, and they need not only to be tackled by increased pilot training and telling pilots off what to do if the system displays its flaws:

Improve the design to the better as well, FGS, even if it means conceding that some well meant gadgets did not work properly. You will only lose face if constantly denying the flaws, but never if you learn of mistakes.

Capn Bloggs 31st October 2011 07:39


So if your aircraft is stalling, how far forward should you move the control column/yoke/sidestick in order to recover?
The forward stop. :ok:

HazelNuts39 31st October 2011 08:06


Originally Posted by Capn Bloggs
The forward stop.

Possibly. I would think that depends to some extent on the airplane's response to forward stick movement. IMHO the important thing is to maintain the pitching down motion until the stall warning stops, and if it returns, pitch down some more.

fireflybob 31st October 2011 08:19


The forward stop.
Capn Bloggs, thankyou.

You move the stick (or yoke/cc) forward until the stall identification ceases - which means, if necessary, the forward stop.

This is basic to stall recovery

When the stall identification ceases you can then level the wings and select an appropriate attitude.

before landing check list 31st October 2011 09:04


When the stall identification ceases you can then level the wings and select an appropriate attitude.
But not too fast. There are always secondary's to think about.

BOAC 31st October 2011 09:21


Originally Posted by blcl
There are always secondary's to think about.


and select an appropriate attitude.
- that is probably why FFB said that bit?

acbus1 31st October 2011 09:45

I'm beginning to wonder if the three AF447 pilots were regular PPRuNe posters. The extent to which this forum manages to complicate simple matters and completely miss the essential points borders on the hilarious. I suspect that observers (media, authorities, whoever) will eventually (if not already) come to regard PPRuNe as nothing more than an easy source of amusement, rather than a worthwhile platform for meaningful debate.

To clarify my criticism of sidesticks (by now located underneath three pages of waffle):

(1) - You might be able to see the other pilot's sidestick. You might be able to see that he's holding it. But can you see, without referring to tiny annunciators, what input he's making?

(2) - The comments regarding current annunciations and the proposals to introduce additional ones miss the point, which is that too subtle an indication of pilot control input is unacceptable.

(3) Two coupled yokes, in clear view, with visible, physical input movements (as opposed to 'motionless' pressure inputs to transducers) presents clear, immediate and unmistakable information.
AF447 would not have ended in disaster had such control yokes been installed. That conclusion applies, despite the unbelievable lack of competence displayed by all three 'pilots'.

Landflap 31st October 2011 10:18

Not a Airbus pilot , Boeing for about , well, ok, all of my life. But, don't you chaps have a sidestick posn indicator? I played in our A340 sim and noticed that there was one, right in front of my face. It was repeated on the other side. Oh, and about Captain's returning after a short break; mate of mine converted to A340 after years on Boeings. During Line Training, Instructor felt safe enough to leave the Flight-Deck. Matey spotted some weather, did a bit of smart Nav, reduced speed to Turb penetration (which was below that lovely little fella... 'Green Dot ' !).Trainer returned and roasted my mate for 'Allowing the speed to fall below green dot'!Big lecture ensued regarding the A340, hot & heavy and not being able to recover the speed loss other than inducing a shallow decent. For the most part, the debate is valuable. safe flying.

FOUR REDS 31st October 2011 10:57

Probably good time to close this thread!!!!!!! :rolleyes:


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