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

From:         rdd@netcom.com (Robert Dorsett)
Organization: Netcom Online Communications Services (408-241-9760 login: guest)
Date:         06 Jun 95 10:11:03 
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In article <airliners.1995.693@ohare.Chicago.COM> cleyman@cix.compulink.co.uk ("Clive Leyman") writes:
>>As the Boeing 777 prepares to enter service, I've been reading alot about the
>>differences in philosophy behind the fly-by-wire concepts at  Boeing and Airbus.
>>The more I read, the more I start to feel that Airbus may have gotten it wrong.
>
>Why should one be right and the other wrong?. Surely there can be more
>than one engineering solution to achieve a given objective?.

If you view it as a trivial senior design project, perhaps.

However, aviation safety has been difficult to achieve.  Engineering has
evolved at a snail's pace: what works, works.  What doesn't, is discarded,
and is replaced with something that does.  Apart from details, airplanes
have changed remarkably little since designs of the 1950s, and, indeed,
with our understanding of the discipline, competing companies can come up
with independent designs that look remarkably similar.

Airbus invented a new gadget, and a new way of doing things.  New flight
control laws.  New flight control restrictions.  New input devices.  New
flight management *philosophies*.

They will argue that this was defined by need.  Yet they also proudly
proclaim that they are, indeed, in the business of crafting a product, which
they can sell against technology held and dominated by American companies.
I.e., technology sells.

The nature of that application of technology is, therefore, the core of
the issue.  It is arguable that they disregarded studies which may have
suggested different ways of designing the sidesticks.  Pilots howled over
the lack of of moving throttles under autothrottle control.  These objections
were ignored, because they went against the comprehensive flight management
philosophy.  And after being thorougly trained (Airbus training has been
called "indoctrination" by some pilots), well, maybe that isn't such a
big deal after all.

The result is that, unlike aircraft which are *incremental* evolutions of
technology--i.e., the 757, with no fatal crashes; the 767 with one; the
A310-300, with three (Karl?)-- the A320 has had *four* in a service life of
less than half that of the other airplanes.

"Wrong"?  When people's lives are at stake, you betcha.    Thousands of
people died in the 1950s and 1960s, while we learned how to design safe
systems.  By the time the death rate was bottoming out in the 1970s,
marketing requirements--defined by the bottom line--introduced a number of
"innovations"--glass cockpits, two-man crews, etc.  The first generation
of such aircraft, released in the 1981-1983 timeframe, seem to have worked
out well.  Airbus' offering in the form of the A320 has not worked out well.

What ticks me off is that sure, they'll learn their lesson.  But in apologia
released last year, senior Airbus officers compared their first years with
those of the 727, now one of the safest airplanes around.  But the arrogance
and unreasonableness of that argument is belied by the fact that that we
*should* have learned our lessons already.  It is unconscionable that they
are testing this new design, and the issues raised with these new design
philosophies, with paying, trusting, passengers on board.

So tell me, Clive, do we have to go through this learning curve when *each*
manufacturer invents its own, highly proprietary, engineering solution?
For the innovations Boeing has introduced into the 777, it is commendable
that they have kept the cockpit interface remarkably *conventional*.





--
Robert Dorsett                         Moderator, sci.aeronautics.simulation
rdd@netcom.com                         aero-simulation@wilbur.pr.erau.edu
                                       ftp://wilbur.pr.erau.edu/pub/av