Re: Aileron control on Airbus

Date:         03 Aug 97 02:50:15 
From:         probbe@mail.dotcom.fr (Patrick Robbe)
References:   1 2
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On 28 Jul 97 01:13:28 , Seth Dillon <bdillon1@mindspring.com> wrote:

>> On a flight to Italy recently, my first on an Airbus, I was looking at
>> the wing and it appeared to me that there were no conventional ailerons.
>> There was a control surface close to the fuselage which showed a lot of
>> activity during the approach but only in a downward direction (on my
>> side - I assume there was a matching one doing the same on the other
>> side :-)
>> At no time did it move up and from the look of it I don't think it was
>> possible anyway. The impression I got was that turns were initiated by
>> increasing lift on the wing at the outside of the turn without a
>> matching aileron decreasing lift on the inside wing.
>
>My only experience is with the A310.  On that aircraft there is an
>inboard "all speed" aileron on each wing and flight and ground
>spoilers.  There is no conventional outboard spoiler as on Most other
>large transports.
On the A320, the roll guidance in made with two ailerons located at
the end of each wing's trailing edge, and by the use of spoilers
located on the top of the wings, closer to the fuselage than the
ailerons. There are 5 pairs of spoilers, amongst which only the 4
outboard ones are used for roll control.

The flaps (trailing edge) and slats (leading edge), which extend
downward, are not use for roll control, but only to increase the wings
surface (to allow the aircraft to fly at lower speeds).

When every aileron and spoiler fails, you can still control the
aircraft with the roll induced from the rudder, but that's another
story... ;-)

Here's a little drawing of the A320 flight controls... Sorry it's very
poor but at least it's ascii!

                                         |      Nose ^        |
                 |---|---|---|---|---|   |           |        |
        Slats -> | 5 | 4 | 3 | 2 | 1 |   |                    |
|----------------------------------------|                    |--
|       Spoilers                         |                    |
|             |  |---|---|---|---|---|   |                    |
|             -> | 5 | 4 | 3 | 2 | 1 |   | Aircraft Fuselage  |
|-----|-----|    |---|---|---|---|---|   |                    |
|  2  |  1  | <- Ailerons                |                    |
|-----|-----|----------------------------|           |        |--
       Flaps -> |     2     |     1    | |      Tail v        |
                |-----------|----------| |                    |

The drawing is not to scale, and shows only the left wing of the
aircraft, but you should be able nevertheless to recognize those
flight controls on the aircraft next time you fly on A320! ;-)

As for other Airbus aircrafts (300/310/330/340) I don't know them so I
can't tell. But the 319/321 is much like the 320.

I hope this helps...

Friendly yours,

Patrick Robbe
<probbe@mail.dotcom.fr>