Re: Airbus A320 flight controls

From:         Bradg@io.org (Brad Gillies)
Organization: Internex Online, Toronto, Ontario, Canada (416 363 3783)
Date:         25 Jan 96 00:55:01 
References:   1
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In article <airliners.1996.43@ohare.Chicago.COM>,
   "P. Wezeman" <pwezeman@blue.weeg.uiowa.edu> wrote:
>   In a recent exchange of postings in rec.travel.air several people have
>mentioned conplaints of a lack of proper force feedback in the Airbus A320
>sidestick control. Could someone who is familiar with the system please
>describe it briefly? In particular, does it work by sensing force or by
>sensing movement? Roughly how much force does it take to operate it? If the
>stick moves, where is the pivot point in relation to the pilots hand and
>what is the range of movement and force gradient? I am also interested
>in any pros and cons of the device.
>

I am a mechanic for an airline which operates A320s and have "played" with the
system alot.
The sidestick is for all intents and purposes a joystick.  It is basically a
series of transducers hooked up to a stick to provide input to a computer.
The feel provided by the stick is artificial.  There is a series of "snubbers"
which give the stick artificial weight.  The harder you push the stick the
more it resists (like the shock absorbers on a car).
The stick provides no tactile feedback to the pilot, so he has to be visually
aware of his situation.  For example if the aircraft for sake of argument had
an aileron which was not deflecting normally there would no less and no more
resistance on the stick.  This also is noted when there is no hydraulics
available.  The stick feels the same with hydraulics as it does without.

The force required to move the stick is roughly equivalent to any madern
joystick such as the thrustmaster.  Except that the stick resists rapid
movement for obvious reasons.

Icannot comment on the force gradient as it changes with the force applied to
the stick.

The pros:
roomier flightdeck in front of the pilots
pilot and F/O get table trays to eat lunch on (or laptop computers)
more game like

The cons:
Not tactile feedback to pilot
decreased situational awareness
more game like

Hope this is what you wanted.
Brad