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Felix Saddler
13th Nov 2006, 23:16
Hi i have been researching the airbus systems/laws and have come across a few questions that puzzled me, here goes:-

1) When the sidestick is moved left/aircraft is banked left does the aircraft keep rolling left until right aileron is applied? Or does the aircraft hold the angle of bank first applied?

2) Is it difficult to fly the plane manually?

3) Are most landings autolandings?

4) And finally what is ment by 'LAW'?

Any help would be appreciated,

Thanks FS

foxmoth
13th Nov 2006, 23:30
1. If you bank left then let go or zero the stick the aircraft will stay at the angle of bank where you let go as long as it is inside the limits - above (45 degrees?) it needs the stick held over or it will roll back to 45 - will not let you bank more than 60 degrees.
2. No problem flying manually, there are differences but you will not notice them most of the time.
3. Your choice though you can only Autoland at fields that are cleared for it so it will depend on the routes you fly - charter you will probably only be able to autoland at just over 50% of the places you land - I normally just about manage 2-3 autolands between sim checks, but that is mainly my choice.
4. "LAW" is the flight control law that controls how the aircraft flies - much of which controls bank angle as in 1. and also what happens with pitch rate, and low and high speed handling.

Felix Saddler
13th Nov 2006, 23:42
Thanks for the feedback, so let me get this straight, when you have let go of the stick after a bank to the left of 20 degrees and the aircraft is still banked at that bank angle and still turning how do you get the airplane to return back to normal, i.e straight and level flight, do you just apply right aileron?

tom775257
14th Nov 2006, 00:45
<< Thanks for the feedback, so let me get this straight, when you have let go of the stick after a bank to the left of 20 degrees and the aircraft is still banked at that bank angle and still turning how do you get the airplane to return back to normal, i.e straight and level flight, do you just apply right aileron?>>

Essentially yes. You are applying a rate of roll rather than controlling the ailerons directly when everything is working ok. You put the aircraft where you want it, and it will stay there (within sensible limits). Therefore if we are in a 20AOB turn to the left and you want to fly straight, move the sidestick to the right and hold a deflection on the stick until you are wings level. It is a beautiful aircraft to hand fly (well, the 320 at least). -/+ 10 feet doesn't seem difficult in good conditions.

To quote I believe a trainer from the USA " Welcome to the Airbus, prepare to be assimilated"

Jimmy The Big Greek
14th Nov 2006, 01:10
I have one question.

Lets say that I am banking right 25 degrees I let go of the stick.....it will hold 25 degrees...right? So if I encounter the some turbulence/gusts that dips the wing the aircraft will try and maintain 25 degrees of bank.

Is controling the airbus like flying a boeing with CWS stearing?

AerocatS2A
14th Nov 2006, 04:35
Another question,

When in a turn do you need to pull back to prevent the nose from dropping, or doe it do this for you?

Does it have a manually operated trim?

Carnage Matey!
14th Nov 2006, 04:45
It does it for you. There is a manually operated trim wheel but you don't touch this inflight unless you are in seriously dire straits.

Ignition Override
14th Nov 2006, 06:37
A buddy who has flown ther A-320/319 over a year came by the c0ckpit as he boarded.

I asked him about rudder input during takeoff with a "V1 cut".

He (among other pilots) said that much less muscle or force is required to keep the plane straight. Some A-320 pilots claim that a crosswind landing takes some practice, although I don't understand how constant inputs on ailerons and rudder can be that different than in the old jets we now fly.:confused:

hetfield
14th Nov 2006, 08:53
Another question,

When in a turn do you need to pull back to prevent the nose from dropping, or doe it do this for you?



As far as I remember until 25 (?) deg of bank it does it for you. Beyond you have to add some backpressure.

Busterpilot
14th Nov 2006, 12:58
1. When you move the stick sideways, you ask for a "roll rate". When you let go of the sidestick the A/C maintains that bankangle and tries to correct for any gusts. Above 33 degrees of bank the A/C returns to 33 degrees of bank if the sidestick is released.

Max bank is 67 degrees as this corresponds to 2.5 G. Up to 33 degrees the aircraft corrects G for bank. This means that up to 33 degrees of bank, the A/C maintains altitude(if you started out at level flight) without any pitch input from you.
Above 33 degrees autotrimming is stopped, and you have to introduce aft sidestick input. Aft sidestick input is a "G-demand" (up to 2.5 G), not a deflection demand. You can see that its easy to fly a 360 with 67 degrees of bank (In theory at least! :) ).

2. No, very easy

3. No, we try to keep them for ourselves!

4. Flight control laws are just a given set of what you can expect when you use the controls. I.e. Sidestick sideways in normal law gives rollrate demand, in direct law it gives aileron (and spoiler) deflection demand.

/Buster

Gary Lager
14th Nov 2006, 13:05
33 deg, het, as Buster points out (edited because I didn't read his post first)

Ignition Override - it's different because a constant input on the stick doesn't give a constant aileron deflection, it gives a constant roll rate.

So you can't fly cross controlled in normal law.

Nor should you need to, example: after flying a crabbed crosswind approach, when it comes to squeeze the aircarft straight with rudder, if you don't apply any stick deflection then you haven't asked for any roll - so the aircraft ensures you don't get any. You just straighten with a rudder input and the aircraft stays wings level itself.

Sort of, anyway...there's a little bit of lag in the system and that usually requires a little tweaking of the sidestick. Not difficult to get used to, just different.

Felix Saddler
14th Nov 2006, 14:52
Thanks, thats just about answered everything i wanted to know! :ok:

FS.

fmgc
14th Nov 2006, 21:43
To really understand the airbus you need to know exactly what you are commanding with the side stick.

With left to right & vice versa movement you are commanding a rate of roll. So with the sidestick in the neutral position you are commanding a zero rate of roll (so if banked already you will maintain that bank angle)

With fore and aft movment you are commanding a load factor, with the stick in neutral you are commading zero load factor.

This is all subject to the limits that previous respondants have commented on.

dartagnan
15th Nov 2006, 10:45
I would like to ad that if you release the sidestick, the side stick comes back automatically in his neutral position, and so no input is given.

on "standard" planes, by example in a turn, you maintain a force in the control wheel and you go with your turn(small inputs).

in the airbus, you point the nose to get an bank angle(big input) and you release the stick.when you finish your turn, you displace the stick in the opposite direction to cancel the bank, and you release the stick.(the computer do the turns for you and maintain your bank/pitch)

there is no pitch angle to give in a 360 turn, the 320 will do the job for you.it is auto-trimmed.

pilots say it take some time to "feel" the aircraft which I belive, so far I "flew" the sim...