AF 447 Thread No. 9
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Not so simple if the pilot isn't used to it, as studi points out.
Manual control does not necessarily mean manual trim
My aircraft
Last edited by jcjeant; 11th Aug 2012 at 01:43.
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Do oh oh Z...
"The pilot can command autotrim from the sidestick. Easy as pie..
If he can command it, it is not AUTO..... He is flying a powered elevator, and if he snuffs Autotrim, he'll get fired....
Auto/Manual, there is a difference....
"The pilot can command autotrim from the sidestick. Easy as pie..
If he can command it, it is not AUTO..... He is flying a powered elevator, and if he snuffs Autotrim, he'll get fired....
Auto/Manual, there is a difference....
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Secondly - autotrim is separate and distinct from flightpath automation and always has been.
Finally - autotrim is separate and distinct from FMS/FMC automation and is slaved to pitch commands made by the PIC. Autotrim is an automatic system slaved to the pitch commands given to the aircraft whether those commands come from the FMC/FD/Autopilot or the guy sitting in the command seat. Autotrim cannot be "snuffed" or disabled through crew action.
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Originally Posted by DozyWannabe
Even if autotrim was limited or disabled in Alternate, the end result of AF447 would have been the same .......
How can you say the end result would be the same?
Until you know why he continued to pull, you just can't make that assumption.
It is very possible that the pilots would have recognized the stalled condition had the stab remained at cruise setting. In that case, every time he released back pressure, the nose would have dropped, and it might have sunk into his conscience that his pull was in fact the problem. But I'll admit that the preceding is just my opinion. You might try the same tactic.
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No CONF, I have a conception of the logic at engineering level. If you want to think of it as a physical analogy, picture a metal sheet in a G-clamp. The Normal Law protections are the G-clamp and prevent the flight surfaces from exceeding a certain position. The closer to the airframe limits the aircraft gets, the tighter the G-clamp is wound, but the protections do not directly order the flight surfaces not to exceed a given position.
Take the G-clamp away and there is no restriction.
Take the G-clamp away and there is no restriction.
G-CLAMP ... I like a dozen of them or is it just an ident ?
Excuse my sarcasm really, but that guy has no limit.
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The pilot can command autotrim from the sidestick
If for some reason .. the command to elevator is blocked (or the elevator is mechanically blocked) the pilot have no more control on autotrim
In manual the pilot can command the elevator and the trim (they are no more linked by a system)
So he have full authority on the two separate moving surfaces
He can even don't use the elevator for control the pitch ....
So ... really it's my aircraft
Last edited by jcjeant; 11th Aug 2012 at 06:55.
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I wonder if the preoccupation of some posters with the THS can be traced to a misperception of its rôle. When releasing the stick in a small airplane, the elevator is released and the airplane goes to the AoA for which it is trimmed.
That is different in a FBW airplane. Releasing the stick does not release the elevator. The elevator goes to the position that will provide 1g. As long as the elevator doesn't reach full travel, the position of the THS is irrelevant for the flight path. The main difference is that the elevator moves quickly and the THS moves slowly. 1° of THS is equivalent to 1.5° of elevator (according to Owain G).
That is different in a FBW airplane. Releasing the stick does not release the elevator. The elevator goes to the position that will provide 1g. As long as the elevator doesn't reach full travel, the position of the THS is irrelevant for the flight path. The main difference is that the elevator moves quickly and the THS moves slowly. 1° of THS is equivalent to 1.5° of elevator (according to Owain G).
Last edited by HazelNuts39; 11th Aug 2012 at 13:04. Reason: correction to make the text more general
Not so simple if the pilot isn't used to it, as studi points out.
Manual control does not necessarily mean manual trim, no matter if you or others wish it was so.
context was the suggestion that it might be a good idea. Comments on
what was actually said might be usefull. Like, for example, whether you
think it might be a good idea and if not, why ?...
Last edited by syseng68k; 11th Aug 2012 at 13:29.
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The pilot and the dog
The pilot's only job is to feed the dog and keep him awake; the dog is supposed to make sure that the pilot doesn't touch anything.
Sunday is coming, and I need some smiles.
It has been recently discussed here (AFAR) what the airplane's computers were doing.
Sometimes, Buses pilots are asking: "what 'she' is going to do"
(I don't need to open here a polemic about male or female computers).
So I propose you, for those who would not have made it yet, to acquaint with this.
If you agree, I'll speak another day about 'The bumblebee does not know how to fly ...but ....'
If you don't understand, likely you never will.
is it just a temporary aberation ?. You're letting the side down
with comments like that and are starting to look like a troll, which
a usenet forum would have a particularly harsh way of dealing
with..
It's not a competition here :-)...
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NeoFit
Thank you for publishing Prof.Dr.Ronald Schmid on Computer in Command.
I would add that an aeroplane is the only mode of transport that is unable to stop whilst in its operating medium ( the air).
The Titanic, could have, should have, stopped. A car cannot be driven in practice on ordinary roads at speeds of only between 30 to 35 mph constantly, without having to stop, somewhere.
Thank you for publishing Prof.Dr.Ronald Schmid on Computer in Command.
I would add that an aeroplane is the only mode of transport that is unable to stop whilst in its operating medium ( the air).
The Titanic, could have, should have, stopped. A car cannot be driven in practice on ordinary roads at speeds of only between 30 to 35 mph constantly, without having to stop, somewhere.
Last edited by Linktrained; 11th Aug 2012 at 18:44.
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@ Dozy W.
Air Inter Ste-Odile:
If Airbus and Honeywell have changed the display FPA / VS on the FCU panel this results from their free choice, not a Court decision.
Instead the prosecutor, in his submissions on appeal, has completely rejected all attempts by experts and all parties to the trial for fifteen years who sought to challenge both the display, the autopilot modes, or that the control laws (not mentioned).
If the charges to be reviewed has not been decided by the Court is that the defendants were not for those wrong approach cards, and not for compensation ground.
Posts of the thread AF447 PPRuNe are not journalists or gossip grand public, but the result of discussions and information done by professionals.
Air Inter Ste-Odile:
If Airbus and Honeywell have changed the display FPA / VS on the FCU panel this results from their free choice, not a Court decision.
Instead the prosecutor, in his submissions on appeal, has completely rejected all attempts by experts and all parties to the trial for fifteen years who sought to challenge both the display, the autopilot modes, or that the control laws (not mentioned).
If the charges to be reviewed has not been decided by the Court is that the defendants were not for those wrong approach cards, and not for compensation ground.
Posts of the thread AF447 PPRuNe are not journalists or gossip grand public, but the result of discussions and information done by professionals.
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Originally Posted by DozyWannabe
Try "thoroughly fed-up cop".