From: (Robert Dorsett)
Organization: Netcom Online Communications Services (408-241-9760 login: guest)
Date:         17 May 95 17:24:46 
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In article <airliners.1995.626@ohare.Chicago.COM> (Brian A. Reynolds) writes:
>My Opinions Only!
>The issue should not be with fly-by-wire per se but rather with the human
>factors elements of the flight deck design.  Airbus seems to feel that
>informing the flight crew of what the automatic systems are doing to the
>aircraft is not relivent.

There is certainly more awareness of ergonomics these days, as ergonomics
seems to have contributed significantly to each of the A320 crashes.  Oper-
ational philosophy, breeding over-confidence--indeed, arrogance--has also
been a factor.

However, to ignore the mushrooming complexity of flight control systems is
a mistake.  A pulley and bell-crank system leading to a hydraulic actuator
is a well-understood engineering problem.

Current digital systems in use on civil transports are hideously complex.
>From a few hundred K for the A320, there are over 10M of code in use on the
A330/A340.  Manufacturers are not implementing simple, open-ended solutions:
they are implementing highly modal systems to which large number of hacks
are applied to "fine-tune" the systems and overcome design failings.

Never mind the issues of introducing high-density semiconductors into a high-
radiation/high-energy environment.

There is mounting evidence that, theoretically at least, electronic-based
systems are not as reliable as their mechanical equivalents, even with redun-

While it is pleasing to see emphasis placed on the current problems of
glass cockpits, it is disturbing to see the FBW component dismissed as a

< steps off soap-box >

Robert Dorsett                         Moderator, sci.aeronautics.simulation