A new Era for Aircraft

Aviation experts expect that today's aircraft will be replaced with some new form of supersonic transport. A 21^st century hypersonic aircraft may open a new age of aircraft design.

The designers of this country displayed the project of such a
supersonic passenger liner among the prospective models at the Aerospace Salon held on the old Le Bourget airfield in Paris. An
elongated fuselage with a sharp nose and without a horizontal stabilizer
makes it look more like a 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 fuselage will be 4 meters and the overall
length - 100 meters, with the cabin accommodating 300 passengers. The
future super planes of such a class will have no windows, but the
passengers can enjoy watching the panorama of the Earth on the TV
monitor at the front of the cabin. They will fly so fast that ordinary
aircraft windows would make the structure too weak to withstand the
stresses at 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 overcome 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 economical as possible is lightening the aircraft by substituting new composite materials for conventional metal alloys. Accounting for less than 5 per cent of the overall aircraft weight, 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 atmosphere friction, a hypersonic aircraft will also require complicated cooling measures. One possibility is using cryogenic fuels, such as liquid hydrogen, as both coolants and propellants. The fuel flowing through the aircraft's skin would cool the surfaces as it vaporizes before being injected into combustion chamber.

In addition, specialists in many countries are currently working on new propeller engines considered much more economical and less noisy than jets. The only disadvantage is that propeller planes fly slower than jet planes. However, it has recently been announced that specialists succeeded in solving this problem. As a result a ventilator engine with a propeller of ten fiber-glass blades has been built, each being five meters long. It will be mounted inthe experimental passenger plane.

Notes to the Text:

1. Le Bourget airfield - аэропорт Ле Бурже

2. the looks - внешний вид

3. heat-insulating materials - теплоизолирующие материалы

4. accounting for - составляя

5. coolant - охлаждающая жидкость

TU-154

The Tu-154 was developed to meet the Aeroflot requirement for a new aircraft to replace the jet-powered Tu-104, plus the Antonov An-10 and Ilyushin Il-18 turboprops. The requirement required economic efficiency on routes from 500 to 3500 km, higher speed than the Tu-104, 50% more passenger capacity, and the ability to operate from runways as short as 2300 meters with low pavement loads.

The Tu-154 first flew on October 4, 1968.

In 1988 modified Tu-154 (dubbed Tu-155 and Tu-156) successfully flew on liquid hydrogen and in 1989 on liquified natural gas used as a fuel in its engines.

The Tu-154 is powered by three rear-mounted low-bypass turbofan engines . All Tu-154 aircraft models have a high thrust-to-weight ratio, this gives them superior performance, although at the expense of poorer fuel efficiency, which became an important factor as the fuel costs grew.

Like the Tupolev Tu-134, the Tu-154 has a wing swept back at 35 degrees at the quarter-chord line. The Tu-154 has an oversized landing gear enabling it to land on runways with low permissible pavement loadings. The aircraft has two six-wheel main bogies fitted with large low-pressure tyres which retract into pods extending from the trailing edges of the wings, plus a two-wheel nose gear unit. Shock absorbers provide smooth ride on the bumpy airfields.

The passenger cabin accommodates 128 passengers in two-class layout and 164 passengers in single-class layout, and up to 180 passengers in high-density layout.

The plane's avionics suite, for the first time in the Soviet Union, is built to Western airworthiness standards and includes an NVU-B3 doppler navigation system, a triple autopilot, an autothrottle, a Doppler drift and speed measure system (DISS), "Kurs-MP" radio navigation suite and others. Modern upgrades normally include a TCAS, GPS and other modern systems. About 900 of Tu-154s have been built, 500 of which are still in service. Many variants of this airliner have been built.

The Tu-154M is the deeply upgraded version, which first flew in 1982 and entered mass production in 1984. It uses more fuel-efficient Soloviev D-30KU-154 turbofans. Together with significant aerodynamic refinement, this led to much lower fuel consumption and therefore longer range. The aircraft has new double-slotted (instead of tripple-slotted) flaps, with an extra 36-degree position (in addition to existing 15, 28 and 45-degree positions on older versions), which allows reduction of noise on approach. It also has a relocated auxiliary power unit and numerous other improvements.

IL-96

The Ilyushin Il-96 is a four-engined long-range widebody airliner, which incorporates advanced achievements in Russian and foreign aerospace technology. The IL-96-300 aircraft is designed by Ilyushin Aviation Complex. The aircraft is powered by four turbofan two-shaft Aviadvigatel PS-90 engines.

The Ilyushin Il-96 is a shortened, long-range, and advanced technology development of Russia's first widebody airliner, the Ilyushin Il-86. Its fuselage is about 4m shorter than that of the IL-86. The airframe is made with a new type high-purity aluminium alloy as well as titanium and steel alloys. Quite extensive use is made of composite materials. The upper and lower surfaces of the wing leading edge and the trailing edge, aft of the rear spar are made of honeycomb panels.

It features supercritical wings fitted with winglets, a glass cockpit, and a fly-by-wire control system. It was first flown in 1988 and certificated in 1992.

The IL-96-300 aircraft equipped with modern Russian made avionics which includes six multi functional color-LCD displays, electro remote management system, inertial navigation system, collision air avoidance system and satellite navigation equipment, and equipment permitting executes flights in RVSM conditions. It allows operating the airplane with two crew members. The avionics correspond to modern requirements on international routes in Europe and North America.

The Il-96-300 has a passenger cabin layout for 262 seats, 18 seats with pitch equal to 54 inches plus 244 seats with pitch equal to 32 inches. Galleys are positioned on the upper deck, 18 containers LD-3 and crew rest room are positioned on the lower deck. There is also stipulated a converting of this layout to the 289 seats layout by changing seats in the business class section from 18 to 44 with seats pitch of 34".