Fires the First Shot in the New A320/737 War with Boeing -
part 3 of 4
New Engine Issues too, and How Airbus
and Boeing Could Respond
An open rotor jet
engine prototype (the front is on the left). These
will revolutionize engine technology when deployed.
Part 3 of
a series on the needed evolution of the Airbus/Boeing
A320/737 aircraft. Click the links at the bottom to read
through the other three articles in the series.
The thing we think of as an
airplane is comprised of two major subsystems - the airframe -
the fuselage and wings; and the engines that power the plane.
Engine technology is as much a
factor in overall plane operational economics as is airframe
Current enhancements in engine
technology, and projected likely future enhancements complicate
how Boeing and Airbus can time the development of new airframes
- an outrageously costly and very time consuming process.
Not Just New Airframe
Technology; New Engine Technology Too
We've been talking in large
part about airframe design and evolution. But that is only
half the puzzle. The other half revolves around the
engines on the plane - engine technology is also steadily
advancing all the time, and each new generation of airplane
engines generally offer greater efficiency, cleaner operation,
and quieter sound levels.
A new plane usually has new
engines as well, for two reasons. Firstly, because each
plane has a specific set of performance requirements for its
engines, and so it makes sense to custom design an engine to
suit the plane (the same as how different cars and trucks have
different engines too).
The second reason is simply
to take advantage of the latest state of the art capabilities in
engine design as well as in airframe design, to make the overall
combination of airframe and engine more appealing in the market.
It is possible to re-engine
an existing airframe. If you re-engine your car, you might
have some derivative issues too - you might need heavier
suspension, a stronger transmission, and if it is a more
powerful engine, perhaps you need to upgrade the brakes as well.
The same analogy applies to
a plane. Maybe you need some changes to the wing design,
maybe you need greater fuel tanks (or maybe smaller ones will
do), maybe you need stronger undercarriage and brakes, and
probably you need some changes to the avionics that control the
engine due to the different 'flight envelope' characteristics of
the re-engined plane. You might even need things such as a
new tail to compensate for more powerful engines and the plane
operating in a single engine scenario.
These costs associated with
re-engining a plane are far from trivial (potentially a billion
or two dollars), and of course, they pre-suppose a willing
engine manufacturer who will invest in the development of the
new engine (many billions of dollars). So planes don't
change engines with a great deal of frequency.
Furthermore, there's the
temptation to add other features at the same time, eg 'If we're
going to add a better engine, why don't we stretch the fuselage
a bit as well to take advantage of the extra engine power' and
before you know where you are, a 'simple' re-engining task has
become a complete new model airplane.
The new competing planes
will be equipped with the latest and greatest in western engine
Reversing the past Russian
practice of handicapping perfectly good airframes with
appallingly bad Russian engines, the new Russian Irkut MS-21
will have a latest generation Pratt & Whitney PW1400G engine.
The new Chinese Comac C-919
will have a latest generation CFM LEAP-X engine.
Both these engines promise
about 15% less fuel consumption than comparable current
generation engines, and their presence on these 'foreign'
airframes also gives the airplanes as a whole a great deal more
A complete new type of jet
There is another twist to
developing engine technologies. There is a radical new
type of jet engine design - the 'Open Rotor' design - expected
to become available in the 2020 - 2025 time frame - a game
changing new type of jet that will massively increase engine
Open rotor engines will add
about another 20% fuel saving over the 15% or so saving offered
by replacing current generation engines with the new generation
engines scheduled for the Russian and Chinese planes.
This level of saving becomes
compelling and will require most airplane models to be re-engined
to stay competitive.
Airplane manufacturers are
factoring in this new development and its time frame for
implementation into how they stage their development and release
of new airframes. It would be unfortunate to design a new
airframe and then only a handful of years later, to have to
redesign it for new engines - the preference is, instead, to do
it all at once rather than in two stages.
The Choices Airbus and (lesserly)
On the face of it, Airbus
and Boeing could do one of two things - they could take a big
step and design a new airframe, and match that with new engines,
or they could take a half-way step, leaving the airfare
essentially as it is, but adding new engines to it.
The benefit of the latter
approach is that it would be quick and easy (comparatively
speaking) to implement, and most of all, it would not cost the
airplane manufacturer(s) a great deal of money, shifting most of
the cost onto the engine manufacturer instead.
The benefit of a complete
new airplane is that it would offer two areas of improvement - a
lighter better design of airframe as well as a matching new
design of engine. The downside is that the cost would be
massively greater and the lead time to get the plane to market
much greater too (and don't forget the pending arrival of the
new type of open rotor jet engines).
There's another disadvantage
too, and understanding this is key to understanding what Airbus
has now announced and what Boeing must do in response.
If either airplane
manufacturer proceeds to design a complete new airframe today,
it will be doing so with today's material technologies.
The company will hope for a family life for the new airplane
series to be anywhere from perhaps 20 to 40 years.
But with the rapidly
evolving knowledge of how best to use composite materials, any
such airframe developed today risks becoming technologically
obsolete in maybe ten years time, possibly even less.
Neither company wants to commit to a new family of airplanes,
costing billions of dollars to develop, but which might only
have a short life in the marketplace before having to be
replaced yet again.
So, on the face of it,
simply re-engineering the present airframes seems like a safer
more prudent step to take, as long as this will both be
sufficient to address the threat posed by new competitors, and
as long as the other company doesn't respond not just with a
re-engineering but a total new airframe design as well.
This is part 3 of a
series on the needed evolution of the Airbus/Boeing A320/737
aircraft. Please see also the other parts of this series :
The vital importance - and growing
problems - of the A320 and 737 families of airplanes
2. Why Airbus and Boeing
don't want to - but must - update their aging airplane series
3. Engine issues and what
Airbus and Boeing could do
4. Boeing's big problems
If you liked this, you might also enjoy our multi-part series 'Where
is Boeing Going'.
Related Articles, etc
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24 Dec 2010, last update
21 Jul 2020
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