over-automation with glass cockpits

From:         johnmhunt@ipa.net (John M. Hunt)
Organization: Internet Partners of America
Date:         22 Jul 96 01:53:11 
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This question applies to all glass cockpits, but perhaps a bit more
emphatically to the A320 family.  I am specifically addressing the
apparent over-automation aspects of modern airliners,  and am not in
any way attacking the replacement of the cumbersome and vulnerable
control cables by electronic "fly-by-wire" signals.

I have been reading over the old archived posting of this news group
(many thanks to you, moderator!) and have come across a large number
of postings regarding accidents or near accidents involving automation
in the "glass cockpit" aircraft.  A recurring theme seems to be the
pilot fighting the computer control system in an attempt to regain
manual control of the aircraft in an emergency.

I cannot imagine any reason why total control of the aircraft on all
three axes and total throttle control cannot be trusted to the pilot
the instant he deems it desirable.  I agree it would be desirable to
provide continuous trim control during autopilot operation to avoid
relinquishing control to the pilot in a seriously out-of-trim
condition, and am willing to make an exception for keeping the yaw
damper operative unless the pilot takes some simple specified overt
action to insist on rudder control independent of yaw control
assistance, but surely this is very easy and non-confusing to
implement.

It is inconceivable that todays pilots with their excellent simulator
training are not at least equal to pilots of an earlier era.  If this
is indeed so, why the reluctance to simply trust the pilot to fly the
aircraft manually?

I realize that some exotic high-performance military aircraft achieve
superior performance by accepting inherent instability which is neatly
overcome by mandatory autopilot assistance, and that such aircraft may
indeed be totally unflyable by ordinary mortals without such
continuous assistance.  I find it beyond belief that newly designed
airliners of the past decade are unstable, other than to Dutch Roll
and our old friend phugoid oscillations.

I also realize that some tiny additional increment in safety may be
achieved by automatically preventing overstressing the airframe by a
ham-handed pilot, but surely this is the classic case of a solution
looking for a problem.

Another pet peeve is the required manual computer keyboard input of
such numeric values as rate of descent.  I have no objection to this,
especially as no really graceful substitute for such data entry comes
to mind.  But surely it would add very little cost to provide a
computer voice confirmation of exactly what the pilot has actually
entered, not, of course, what he THOUGHT he was entering..  Such a
service could even be provided selectively in languages other than
English to provide the greatest possible reassurance to a sizeable
portion of the world's airline pilots.  It is awfully difficult to
imagine a scenario for such automated voice confirmation seriously
misleading the pilot in the event of partial and unidentified failure
of the voice feedback circuitry, since the pilot. if at all
suspicious, can easily verify the actual setting by existing numeric
displays.

Anyone have any thoughts in this area?
John M. Hunt
johnmhunt@ipa.net