Re: FLY-BY-WIRE (AIRBUS vs. BOEING)

From:         bareynol@cca.rockwell.com (Brian A. Reynolds)
Organization: Rockwell Avionics - Collins, Cedar Rapids, IA
Date:         17 May 95 01:06:21 
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Followups:    1
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*****
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.  For instance, throttle handles are not moved
as the autoflight system manages thrust.  The side sticks are not tactilely
connected to the respective control surfaces (let alone from side to side).
In addition, Airbus allows the control systems to override flight crew inputs.
All of these, IMHO, creates a flight deck environment of 'the airplane can
take care of itself' leading to (again IMHO) many cases of either hubris (as
in the first A320 incident) or plain misunderstanding of what the airplane is
doing (CAL and now TAROM?).

In both the 777 and the IL-96M/T the flight crew is kept 'in the loop' by
feedback from the automaic systems to controls.  The controls move as if they
were mechanically coupled.

So the issue should not be HOW the surfaces are commanded to move, but rather
how much the flight crew is AWARE of their movements.  Keep in mind that even
the DC-10 (a 60's vintage aircraft) is 'fly-by-wire' when the autopilot is
coupled in.  The cables are used only to provide the feedback to the
flight controls!  (All that the'real' fly-by-wire systems have done is to
removed this manual reversionary mode!)

So, I think that Airbus did get the system concept wrong by not providing the
flight crew with tactile and visual feedback.

******************
The preceeding are my own opinions and have not been reviewed nor endorsed
by anyone else within Rockwell.
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