Re: Are Two Engine 757 & 767 Jets Dangerous?

Date:         05 Dec 96 02:27:19 
From:         Stefano Pagiola <spagiola@worldbank.org>
Organization: World Bank
References:   1 2 3 4 5
Followups:    1 2 3
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H Andrew Chuang wrote:
> >BTW why did Airbus design a new *four* engine plane A340 and, not like
> >the 777 a twin-engine A340 ?
>
> ... The fact that Airbus needed to put four engines on the A330
> and called it the A340 was because there was no suitable engines
> available at the time.  If the B777-class engines were available at
> the time the A330/A340 was launched, I doubt the A340 would have existed.
> Airbus rushed the launch, that's why a plan to stretch the A330 (i.e.,
> A330-400X) was shelved.  The stretched A340 is waiting for a new
> engine.  To have a single aircraft program powered by three different
> classes of engines, IMHO, is very very poor planning by Airbus.

By 3 classes you mean the A330 and its engines (1 class), the current A340
and its engines (1 class), and the proposed A340-500/600 and its engines?
I'll grant that it is unfortunate for the A340 to require two classes of
engines.  That the A330 should is not surprising, however.  The A330 was
specifically designed to fill what Airbus saw as a very different market
niche from that filled by the A340 ("short- to medium-haul heavy-traffic"
vs "long thin").  What's surprising to me is that they were able to fill
these two niches with a common airframe and wing, not that two different
types of engines were required.

So, that leaves two questions:

First, should the 4-engine A340 have been built at all? ie, are you
correct in supposing that it would not have been had 777-class engines
been available at the time?  If one judges by the continuing demand for
the A340 even now that the 777 is available, including by airlines that
have 777s on order (eg Cathay), it would seem that not all agree with you.
Lufthansa explicitly preferred the 4-engine A340 for its long routes.

Second, given that Airbus wanted to proceed with a 4-engine aircraft, is
the fact that stretched versions will need a new class of engines "poor
planning"?  It may well look that way.  But consider that Airbus was
already late compared to Douglas.  If the A340 hadn't been available when
it was, Douglas would likely have picked up most of those orders, probably
allowing it to overcome the problems it faced trying to introduce the
MD-11 at the time of the Gulf War.  By the time the A340 came around with
the perfect engine, there would have been little market left (especially
with Boeing squeezing from the other end).  Would Airbus have preferred to
launch the A340 with an engine better-sized to it, rather than one
stretched to the limits of its potential?  Sure.  But they did not have
one available, so they went with what they had, which did the job that
current market conditions demanded.  I submit that there's a difference
between accepting a trade-off and "very very poor planning."

--
Stefano Pagiola
850 N Randolph Str No.817, Arlington VA 22203, USA
All opinions are my own and do not necessarily reflect
those of my employer