A New Era for Aircraft Aviation experts expect that today's aircraft will begin to be re-
placed with some new form of supersonic transport in a few years'
time. A 21st century hypersonic aircraft may open a new age of air-
craft design.
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The designers of this country displayed the project of such a su-
personic passenger liner among the prospective models at one of
the latest Aerospace Salon held on the old Le Bourget airfield in
Paris. An elongated fuselage with a sharp nose and without a hori-
zontal stabilizer makes it look more like rocket. The speed
matches the looks. This plane will fly at a speed five to six times
above the speed of sound, e.g., it will cover the distance between
Tokyo and Moscow in less than two hours. The diameter of the fu-
selage will be 4 meters and the overall length 100 meters, with the
cabin accomodating 300 passengers. The future superplanes of such
a class will have no windows, but passengers can enjoy watch-
ing the panorama of the Earth on the TV monitor at the front of
cabin. They will fly so fast that ordinary aircraft windows would
make the structure too weak to withstand the stresses such a
speed. At high velocities the air resistance in the lower atmosphere
is so great that the skin is heated to very high temperature. The only
way out is to fly higher. Therefore, airliners' routes will mainly lie
in the stratosphere.
In general, to build a reliable hypersonic plane one has to over-
come a whole set of technological and scientific difficulties. Apart
from creating highly economical combined engines and heat-
insulating materials, designers have to make such an amount of
thermodynamic computations that can't be performed without
using supercomputers. One of the ways to make planes as economi-
cal as possible is lightening the aircraft by substituting new com-
posite materials for conventional metal alloys. Accounting for less
than 5 per cent of the overall aircraft weight now, the percentage of
composite material parts will exceed 25 per cent in new generation
models. An extensive use of new materials combined with better
aerodynamics and engines will allow increasing fuel efficiency by
one-third
Because of the extreme temperatures generated by the atmo-
sphere friction, a hypersonic craft will also require complicated
cooling measures. One possibility
is using cryogenic fuels, such as
liquid hydrogen, as both coolants and propellants. The fuel flow-
ing through the aircraft's skin would cool the surfaces as it vapor-
izes before being injected into combustion chamber.
In addition, specialists in many countries are currently working
on new propeller engines considered much more economical and
noisy than jets. The only disadvantage that propeller planes
fly slower than jet planes. However, it has recently been announced
that specialists succeeded in solving this problem. As result a
ventilator engine with a propeller of ten fibre-glass blades has been
built, each being five meters long. It will be mounted in the experi-
mental passenger plane.
т1. What is this text about? 2. What aircraft was displayed in
Paris? 3. What are the characteristics of the new liner? 4. What are
the difficulties in building a hypersonic plane?
