Re: Airbus sidestick

From:         "peter (p.j.) ashwood-smith" <petera@bnr.ca>
Organization: Bell-Northern Research, Ottawa, Canada
Date:         08 May 95 02:09:05 
References:   1
Followups:    1 2
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In article <airliners.1995.557@ohare.Chicago.COM>, irf1001@thor.cam.ac.uk (Ian Furlonger) writes:
|> Are any pilots out there prepared to comment on the ergonomics of the
|> Airbus "sidestick", as opposed to the traditional control column? Boeing
|> are sticking with the latter, but I can appreciate the attractions of an
|> uncluttered cockpit, especially if the bulk of landings are performed
|> automatically.
|>
|> When learning to fly a Piper Tomahawk, my instructor advised me only to use
|> the left hand on the control column, thus leaving the right hand free for
|> all the central controls. But I would still ask whether an Airbus captain
|> might be disadvantaged by being restricted to the use of his left hand for
|> controlling the aircraft upon landing...

   The issue is not ergonomic or comfort but one of safety. It is clearly
safer to have two mechanically connected control columns than two electronically
connected side sticks.

   The mechanically connected control columns provide feed-back from one pilot
to the other as to what is happening and provide more leverage so that manual
control systems can still be employed as last ditch when all else fails.

   Ask yourself this, when both pilots move the side stick what input do you
give the plane. Answer: why you average the signals of course! Question:
what happens if they both move it in opposite directions? Answer: well then
the average is zero isn't it! Question: so the plane does nothing? Answer:
Yes, but don't worry there is a little button you can push to override the
other pilots inputs and take control.

   These things are accidents waiting to happen and I'm sure Airbus uses them
because they save weight and are cheaper to make than a pair of mechanically
connected columns.

   Peter

   I'd be willing to bet the last 10 seconds of any A320 flight data recorder
shows them two little sidstick buttons toggling like mad!