Early jet and turboprop airliners

THE BASIS OF THE AIRLINE BUSINESS is not technical innovation or elegance of design, but the economic equation of passenger numbers against operating costs. Jet engine technology did not at first seem an attractive proposition to airlines because of high fuel and maintenance costs and low passenger payload. Turbojets were developed in the postwar period to provide some of the comfort and speed advantages of jets, but with more economical operating costs. The Boeing 707 was the breakthrough jet that could carry enough passengers fast enough to make it profitable on long-distance routes. Its success in the 1960s left plenty of room at the bottom for less powerful airliners that could use smaller airports or operate on shorter routes where it was important to perform economically at slower speeds. The BAC 111, one of the few commercially successful British aircraft, catered for this market, as did Douglas’s DC-9, but once again it was Boeing that tailored airliners most precisely to the needs of its customers with the 727 and 737.

In the 1960s everyone in the airline business assumed that supersonic commercial jets would be the next big thing. The history of airliners seemed to show that increase in speed was a constant factor. In the 1930s the DC-3 had flown at 290kph (180mph); in the 1940s the four-engined propliners flew at upwards of 480kph (300mph); the turboprops flew at around 640kph (400mph) in the 1950s; and the Boeing 707 was carrying passengers at 960kph (600mph) in the 1960s. Why should this acceleration of commercial flight cease?

It seemed a fair assumption that, given the choice, passengers would always opt for the shortest journey time, and thus the fastest aeroplane. As with turbojets, there were daunting problems to overcome, especially in the commercially crucial relationship between fuel consumption, payload, and range. But with the supersonic transport (SST) apparently the new holy grail for the aircraft industry, designers and engineers bent to the task.

Supersonic showdown Three SST projects developed through the 1960s: the Anglo-French Concorde; the Soviet Tupolev Tu-144; and, in the US, the Boeing 2707. They were so costly that only government money could cover the expense – even Boeing depended almost entirely on federal funding. In many ways the SST projects were close in spirit to their contemporary, the American Apollo moon-landing programme, driven by the same technological imperatives and heightened national pride, rather than by considerations of profit or practical advantage.

The Anglo-French and Soviet projects got under way more quickly, but the Americans were more ambitious, setting their sights on Mach 3 flight – around 3,200kph (2,000mph) – while their SHRINKING WORLD rivals settled for Mach 2. The Concorde and Tu-144 developed into such superficially similar, slender, delta-wing designs that in the West there were inevitable rumours of espionage. In fact, the number of possible solutions to the problem of designing an SST was very limited, and it is hardly surprising that two teams independently came up with a similar shape – no more surprising than that all three SSTs had a movable nose (to give better visibility on landing). Boeing pursued a radically different design, with a variable-geometry wing. It was not only intended to fly faster than its rivals, but also to carry more than twice as many passengers.

The Tu-144 made its first flight in December 1968, followed by Concorde in March 1969. Meanwhile the Boeing SST was in trouble: the variable-wing concept had had to be abandoned and the projected passenger payload scaled down.

Boeing 747 (“Jumbo Jet”)

Wide-bodied jets

The entry of the wide-bodied Boeing 747s into service in 1970 carried this process to a new level. The message of the 747’s success was that air travel was going to be mass travel. Airports had to reinforce runways and expand passenger and baggage handling facilities, initially swamped by 300 or 400 people disgorging at once from a single aircraft. In-flight caterers had to adjust to supplying their fare in previously undreamed of quantities. Hotels had to be built to cope with the rising tide of travellers.

The 747 represented no great technological breakthrough, just better engines and business daring. Other wide bodies inevitably came in its wake as rival manufacturers sought to break Boeing’s increasing domination of the market.

They could not challenge the giant 747 head-on, but sought out a market share among airlines for which the 747 was just too big. McDonnell Douglas came up with the DC-10, Lockheed produced the TriStar, and a new consortium of European manufacturers, Airbus Industrie, built the Airbus A300. The DC-10 and TriStar were three-engined airliners competing for the same market niche; they inevitably ran into commercial difficulties because there was not enough room for both of them. Lockheed, who came off worse in this contest, never made an airliner again. The Airbus A300, on the other hand, was a major success.

With only two engines and two crew members in the cockpit, it marked a significant step forwards in economy of operation. By the 1980s Airbus Industrie had established itself as Boeing’s most vigorous competitor on the world market.

From the 1970s jet flight became an experience open to everyone. As such it inevitably lost its connotations of glamour, romance, or excitement. The European consortium’s choice of the name “Airbus” for its product spoke volumes about the prosaic nature of air travel in the age of the wide-bodied jets. Most passengers on a 747 did not even have a window. Much effort was devoted to distracting passengers from the fact that they were flying at all, insulating them with in-flight entertainment and reducing them to passive consumers of duty-free goods, snacks, and drinks.

One jaundiced journalist referred to modern air travel as “the most constrained form of mass transport since the slave ships”.

FLYING CAR

Molt Taylor’s Aerocar, marketed in the 1950s, was one of the most ambitious efforts to create an aircraft for people to keep in their garage. It is shown here in both flight and automobile mode – the wings are folded up in the trailer.

The idea of flying an aircraft as an activity open to millions has remained one of the frustrated dreams of aviation. As early as 1924 American automobile manufacturer Henry Ford envisaged a future in which aircraft would be produced in similar numbers to cars. In the 1930s American air administrator Eugene Vidal was a prominent campaigner for a “poor man’s airplane”, a Model T Ford of the air, that would transform flying from “a rich man’s hobby to a daily utility or inexpensive pleasure for the average American citizen”. From the 1920s onwards, private aviation in light aircraft did become a popular sport open to the moderately affluent. But the notion of an aircraft parked in every driveway never came off.

There were several attempts to produce flying cars – vehicles that could be driven on roads as well as fly through the air. Perhaps the most promising was Molt Taylor’s Aerocar, produced in the 1950s. The flying surfaces folded up to turn the aeroplane into an automobile; the engine drove a propeller when in aircraft mode and the wheels when it was being driven on the ground. But the Aerocar’s dual function involved too many compromises to perform well enough in either genre.

There were also attempts at making aviation very cheap, of which perhaps the most memorable was Frenchman Henri Mignet’s Pou du Ciel, or Flying Flea. Brought out in 1933, this tiny aircraft was sold in kit form, to be assembled at home.

After some 30 days’ hard work, the purchaser would have a machine capable of reaching 130kph (80mph), but with a landing speed of only 30kph (19mph).

Early jet and turboprop airliners - student2.ru

THE FUTURE OF FLIGHT

IN THE GREEK MYTH that so fascinated many of the earliest pioneers of flight, Daedalus’ son Icarus died after flying too close to the sun, which melted the wax on his feathered wings. In 2001, ironically inverting the mythical experience, a NASA Helios ultralight flying wing powered by the sun’s rays flew to the outer edge of the earth’s atmosphere.

Surely one of the most extraordinary aircraft yet built, Helios is “piloted” by a controller on the ground and travels at a sedate 32kph (20mph). Its wing, measuring 75.25m (247ft) and thus longer than that of a Boeing 747, is covered in solar panels that generate the electricity to drive its 14 motors. Storing electricity in fuel cells during the day allows it to continue to operate through the night. Totally ecologically friendly, Helios is destined for sustained flight at the edge of space. On 13 August 2001 it set an altitude record for a propeller-driven aircraft, rising to 29,511m (96,863ft). The earth’s atmosphere at that altitude is similar to the atmosphere of Mars, so the flight allowed NASA scientists to learn about the feasibility of a flying machine that might cruise the skies of the “red planet”. Helios could also serve many of the functions of a satellite – in communications or weather observation, for example – at a fraction of the cost. With no need to refuel, NASA believes Helios will eventually be able to fly for months at a time – in effect until its parts wear out.

Distance travelled

Helios is a superb example of the constant power of aviation to amaze with unexpected feats of technological innovation, revealed time and again through the 20th century. Looking back at the distance flight advanced in its first 100 years offers a vertiginous perspective. Any measure of aircraft performance reveals dizzying progress – speed, for example, accelerating from Glenn Curtiss’ record-breaking 75kph (47mph) in 1909 to top speeds passing 640kph (400mph) in the 1930s; the breaking of the the sound barrier by the end of the 1940s; and aircraft reaching Mach 2 and Mach 3 in the 1960s, topping out with the X-15 at Mach 6.7 in 1967. C-5 transport introduced at the end of the 1960s could carry about 100 times the payload of a World War I bomber, and has itself been far surpassed by transports such as the extraordinary Airbus Beluga series, capable of carrying cargoes well in excess of 50 tonnes.

The history of flight’s impact on the world shows a similar acceleration. If you were writing a general account of life in the 20th century, aircraft would only figure marginally for the first three decades. Some reputable single-volume histories of World War I barely mention aviation at all. Until the late 1930s, aircraft were a craze that generated heroes, but really had little effect on the lives of any but a small minority of people.

It was World War II that truly brought aircraft centre stage, transforming the practice of warfare. Commercial aviation took until the jet age to begin to effect a dramatic change in leisure and business. Even in the United States, in the early 1960s half the population had still never flown.

But by the 1990s over a billion passengers were flying worldwide every year. It was an open question at the start of the third millennium whether flight still had revolutionary possibilities, or whether it hadbecome, like tanks in warfare or railways in passenger transport, an established feature of the landscape that would endure (with improvements) but undergo no further dramatic expansion or transformation.

BIGGER JUMBO

The giant Airbus A380 should be carrying its payload of 550 passengers in airline service by 2006. The A380’s unprecedented wingspan and weight will require airports to upgrade their facilities, as they had to when the Boeing 747 was first introduced in the 1970s.

The latest American fighter ready to go into service in the first decade of the new millennium, the Lockheed Martin F-22 Raptor, was an advance over its predeccesors in its stealth features and its ability to cruise at supersonic speed – all previous fighters could only “go supersonic” in short bursts because of fuel consumption. But it was not a dramatic revision of the fighter concept. Vectored thrust was one of the most radical areas being explored in experiments with fighters, Passenger travel Before the terrorist attacks of 11 September 2001 (see page 410), the aircraft industry was predicting that four billion passengers a year would be carried by 2020 – almost triple the current level of air travel. Boeing confidently stated that the world’s commercial air fleet would increase from 14,500 to 33,000 airliners in the first 20 years of the new millennium. The implications of this for airports and airways was, in its way, daunting. After 11 September the shocking fall in passenger numbers made a permanent end to growth in air traffic seem not out of the question. Perhaps the best that can be said is that the future is unpredictable.

The airline and aircraft-manufacturing businesses have always been financially precarious, subject to downward pressure on prices and upward pressure on costs. And so it will remain. The two options open to the airline business, if it were to change, were bigger airliners or faster airliners. The only two manufacturers left in the civil-aviation big league, Boeing and Airbus, seemed to have opted for opposite strategies.

Airbus A380 looked ready to head the field in the size stakes, promising to carry 550 passengers and be in service by 2006. Boeing instead were pushing development of the Sonic Cruiser, intended to carry 200 to 250 passengers at almost the speed of sound – upwards of 0.95 Mach – over a distance of 9,500 to 14,500km (6,000 to 9,000 miles).

The supersonic option seemed to have taken refuge in the private aviation sector, with ideas being floated for a supersonic private jet, the ultimate personal and corporate status symbol.

Military aircraft

Military aviation was in a sense in the ascendant in the early 2000s, the key to power projection in a still-hazardous world, with citizens in technologically advanced democracies accustomed to peace and reluctant to countenance the level of casualties ground war usually involves. Drones were an increasingly popular and effective option, both for battlefield reconnaissance and carrying out air-strikes, completely obviating the risk of human losses. But cost-conscious politicians were increasingly inclined to query the need for ever more expensive aircraft, which could easily seem like toys for the boys to play with. In the United States, the technological lead over any currently conceivable enemies might prove a deterrent to investment in expensive high-tech military SHRINKING WORLD allowing previously impossible manoeuvres, but again it could hardly be seen as a revolutionary innovation.

The Raptor’s extreme cost was controversial, although it was argued that it was justified by the need to keep up with Russian technology. It was increasingly difficult to see why a war with Russia would be fought, but it could plausibly be argued that the Russians might sell their most advanced aircraft to a country that America might feel called upon to fight. The Russian Sukhoi S-37 Berkut, with its forward-swept wing, was, on the face of it, a more radical design break than any experimental Western fighter, but it was unclear whether the Russians had the money or the will to press on at the cutting edge. Western governments certainly showed signs of tightening the purse strings. The cheaper Joint Strike Fighter, planned to be mass-produced as NATO’s future standard fighter aircraft, was a deliberate compromise between cost and technology.

Open frontiers

Space exploration remained the open frontier where, at least in theory, boundless possibilities existed for new achievement. Although the ideal of an aircraft that would take off under its own power and fly into space has still to be realized, the shuttle and space stations have already begun to make space flight a once-in-a-lifetime vacation experience available to the ultra rich. Enthusiasts such as former astronaut Buzz Aldrin are seriously talking about journeys to Mars in the 2020s. Projects for moon colonies and Mars colonies still have plausibility, and serious scientists speculate about a future in which humans or their self-replicating computers spread through the galaxies. At the start of the third millennium it was hard to see space travel affecting most people’s lives except in science fiction scenarios, yet the apparently fantastic has become real before.

Early jet and turboprop airliners - student2.ru

WHITE WHALE

The extraordinary Airbus Beluga is the world’s largest transport aircraft by volume. It is basically the bottom half of an A300 wide body airliner with a bulbous cargo hold mounted on top. The Beluga was designed to carry sections of Airbus airliners between factories in different countries

FEAR OF FLYING

STATISTICS PROVE THAT FLYING IS BY FAR THE SAFEST WAY OF TRAVELLING LONG DISTANCES, BUT AIR ACCIDENTS INSPIRE A MORBID FASCINATION THE AIRLINE INDUSTRY has always known that its success depends on convincing the public that air travel is safe. This has never been an easy task. The drama of major air disasters impresses itself so intensely on the public consciousness – partly, no doubt, precisely because they are rare – that flying is often inextricably associated in people’s minds with sudden and violent death. Yet measures to reduce the number of air accidents and aviation-related deaths may undermine the image of air travel as a normal, safe, everyday experience. The more safety procedures air passengers are subjected to, the less secure they are likely to feel. Surely flying cannot be that safe if we are searched before boarding and flight attendants insist on telling us where the oxygen masks and emergency exits are? For the nervous, there is nothing quite so disquieting as constant reassurance “for your comfort and safety”.

Yet the figures are unequivocal. Although accident statistics fluctuate from year to year, flying on a commercial airliner always emerges as by far the safest way of travelling long distances. In 1996, for example, a relatively bad year for aviation deaths, a total of 1,187 people were killed on commercial jet flights worldwide. This compares with over 40,000 people killed that year in road accidents in the United States alone, and worldwide probably a quarter of a million roadaccident deaths. Flying is far from being equally safe in different parts of the world: in a typical year, the United States might have one flight fatality for every two million passenger-hours flown, while Africa might have 13 fatalities per million flight hours. But even in Africa you are more likely to be killed or injured driving to and from the airport than on board the aeroplane. The risk of a fatal accident each time you board an airliner has been calculated at roughly three in a million. This means that if an otherwise immortal individual made a flight every day, he or she could expect, on average, to survive for over 900 years before dying in an air accident. (Flying in a private aircraft carries a quite different risk – it is almost 50 times more dangerous than flying in a commercial jet.)

Progress on safety has been the necessary condition for the development of mass air travel. In the early 1930s, there was a fatality for every 4.8 million passenger-miles flown in the United States. In a single, admittedly exceptional, period in the winter of 1936–37, there were five fatal air crashes in the US in 28 days. Translated into the contemporary world of widebody jets, a 1930s style accident rate would have produced a totally unacceptable mass of fatalities. By the 1980s, American airlines flying major routes had reduced the death rate to around one for every 300 million passenger-miles. Even so, recent decades set all the records for air disasters, because of the large numbers of passengers on a single flight.

The worst year for air-accident fatalities worldwide was 1985, with 2,129 people killed – although 1,105 of the victims died in just three incidents. In 2000, a fairly average year for aviation in recent times, there were 1,126 deaths worldwide. To put this figure in perspective, there were by then some 1.5 billion passenger flights being made worldwide every year, over 600 million of them in the United States. The safety of commercial flying is a triumph of organization and regulation, and a tribute to the professionalism of all involved in the aviation business, from those who make the airframes, engines, and avionics, through the ground maintenance staff and flight crews to administrators and air-traffic controllers. The volume of traffic that air-traffic control has to cope with has, of course, increased dramatically in the jet age. By the late 1990s there were some 7,000 flights a day into and out of New York.

To look at it another way, controllers at Chicago’s O’Hare airport were responsible for the safety of around 70 million passengers a year. But despite occasional panics about overstretched air-traffic controllers being overwhelmed by numbers, the system has continued to cope well. So has the system of periodic checks and overhauls designed to ensure that aircraft are fit to fly, with faultless engines and free of structural weaknesses.

Considering what amazingly complex machines modern aircraft are – a Boeing 747 has about 4.5 million moving parts – it is astonishing how rarely they suffer serious faults. A modern jet may have ten hours ground maintenance for every hour it spends in the air.

FUTURE BOEING PROJECTS

For sale after 2007, Boeing planned to build a new 700- mile-per-hour Sonic Cruiser, which will reduce the current seven-hour transatlantic airline journey by one hour. Boeing also planned to increase aircraft speeds significantly with an entirely new engine technology using a mixture of conventional jet fuel—derived from oil, a fossil fuel— with clean-burning hydrogen. Prior to Boeing’s new tests, the top speeds of commercial aircraft had been stagnant since 1970, when the record for the fastest civilian aircraft (1,600 miles per hour) was set by a Russian Tupolev Tu- 144. Typical jet aircraft speeds (500 miles per hour) had not changed since the 1950’s.

In 2001, Boeing unveiled a prototype superfast aircraft that could fly passengers between London and New York in forty minutes. In May, the Hyper-X, “a flying engine that looks like a surfboard with fins,” designed jointly by Boeing and NASA, was tested over the Pacific Ocean 75 miles off Los Angeles.

In the engine test, the Hyper-X was bolted beneath the wing of a B-52 bomber. The B-52 released the “flying surfboard” at 20,000 feet, as a conventional booster rocket drove it to about 2,000 miles per hour. Revolutionary scramjets then cut in and, for ten seconds, the hypersonic plane reached a maximum speed of 5,000 miles per hour, making it the fastest aircraft in history.

Ordinary jet engines are propelled by blades that drag air into a chamber, compress it, mix it with jet fuel, and explode it out of the rear to create forward momentum.

Scramjets have no blades, but depend on previously generated speeds to force air through an oval-shaped mouth into a copper chamber, where it mixes with hydrogen to produce a much more powerful explosion.

The Hyper-X can fly at speeds of up to 5,000 miles per hour, more than three times as fast as the next-fastest airliner, the thirty-year-old Concorde, which had become technologically obsolete by the year 2000. Other tests were foreseen with prototypes able to fly as fast as 7,000 miles per hour. Such vehicles could circumnavigate the earth in fewer than four hours. Boeing intended initially to design such aircraft for the U.S. military and then to build a bigger version for cargo operators. After all tests were completed, Boeing would build a version for commercial customers, such as British Airways, starting in 2016.

Boeing’s hypersonic aircraft would be much smaller than the jumbojets that comprised parts of many airline fleets during the late twentieth century. The bigger planes lack the structural integrity required to withstand vastly accelerated speeds. The development of hypersonic aircraft also has been made possible by advances in the strength of manufactured metals. For structural reasons, the new airliner probably will have no windows. Passengers will be protected from a gravitational force of 6 g’s by a highly pressurized cabin. The aircraft also will accelerate and decelerate slowly to lessen the effects of changing gravity. Such aircraft also will produce sonic booms as they accelerate, so routes will need to be configured to avoid large population areas at the point of transition to hypersonic flight.

Pilot/Controller Glossary

Even pilots native to English-speaking countries may have widely diverging accents, and syntax differs from region to region in many countries. In the United States, after 1972 the FAA established a pilot/controller glossary in the AIM that put forth words and phrases that were largely compatible with those of the ICAO. These words had developed by trial and error since the 1930’s, and the FAA found them both efficient and effective. Common words include “Affirmative” to answer a question “yes,” while “negative” answers such a question with “no.” Flight students soon learn that on the radio, monosyllabic words such as “yes” or “no” might not transmit over the radio. Within the United States alone, different regions say “yes” in fashions confusing to the inhabitants of other localities. A commonly misused aviation word, “Roger,” means simply that the hearer has received all of the last transmission. It does not indicate compliance with an instruction, nor understanding of information. When pilots or controllers do not understand a transmission, they should ask the sender to “Say again.” AIM Phonetic Alphabet

Letter Word Pronunciation

A Alpha al-fah

B Bravo brah-voh

C Charlie char-lee or shar-lee

D Delta dell-tah

E Echo eck-oh

F Foxtrot foks-trot

G Golf golf

H Hotel hoh-tel

I India in-dee-ah

J Juliet jew-lee-ett

K Kilo key-loh

L Lima lee-mah

M Mike mike

N November no-vem-ber

O Oscar oss-cah

P Papa pah-pah

Q Quebec key-beck

R Romeo row-me-oh

S Sierra see-air-rah

T Tango tang-go

U Uniform you-nee-form or oo-nee-form

V Victor vik-tah

W Whiskey wiss-key

X X ray ecks-ray

Y Yankee yang-key

Z Zulu zoo-loo

Not all pilots agree with the principle of standard phraseology. To teach standard phraseology takes time, and its benefits are not readily apparent with each use. Articles in aviation magazines occasionally have derided established phraseology, some authors belittling aviators who used it or instructors who taught it. Many of these too quickly embraced the AIM’s allowance that, should a pilot’s understanding of phraseology fail, he might simply speak conversational English. Others retorted that every pilot’s public duty is to learn the system and be a fully functioning part of that system, which includes established communications standards.

Within the aviation community, as in most others, effective communication remains elusive. Yet while other industries tend to have codes or jargon for internal use, the decades have forged aviation’s communications system into an English-based specialty language. As such, aviation- speak is inefficient for face-to-face conversation but very succinct for time-critical communications in a fluid environment. That fact and its implications are only just beginning to make inroads into the flight training environment.

Flight schools still concentrate on teaching aerodynamics, airplane systems, maneuvers, regulations, weather, or myriad other subjects that at the time seem far more immediate than communications. Overall, the aviation industry continues to awaken to communications as a serious public safety issue.

Air shows are events featuring the exhibition of aircraft and the demonstration of aviation skills. Early air shows helped to promote aviation and increase public awareness about the excitement of flying. Air shows continue to display the latest in aviation techniques and development.

The first airplanes had more value as curiosity pieces than as means of transportation. For ten years after the Wright brothers’ flight of 1903, aviation was kept alive by devotees who toured the country while performing at circuses, fairs, and anywhere else people would pay to see them. These daredevils performed aerobatic feats, walked on airplane wings, made parachute jumps, and took paying customers for joyrides. Many of these pioneer pilots died in pursuit of their aerial adventures, but they lent an air of romance and danger to the new field of aviation.

World War I-era pilots often had little or no training, flying instead by instinct and sheer courage. During the war, these daring pilots flew into combat zones with courage and determination.

After World War I, the U.S. government offered thousands of surplus airplanes, most of them Curtiss Jennys, for sale at bargain prices. Although these airplanes were stronger than those that had been built before the war, they were not always safe. Made mostly of wood and cloth, they also lacked satisfactory navigational equipment. However, many former military pilots bought these airplanes and used them for an exciting and dangerous type of flying called barnstorming.

Barnstormers toured the United States in the 1920’s and put on daring air shows at county fairs and other events. Audiences were thrilled to watch. The pilots flew the airplanes in wild aerobatics and daring stunts. Performers, called wing-walkers, stepped from wingtip to wingtip in midair or leaped from the wing of one flying airplane to another. There were many accidents, some fatal.

Highly skilled World War II pilots were used to faster, more technically advanced airplanes than those of World War I. Although World War I dogfights had spurred aviators to postwar displays of courage and craziness with aerobatics, barnstorming, and cow-pasture thrill shows, post- World War II pilots had more venues in which to display their skills, including air races, air shows, carnivals of the sky, and precision flying. The air shows of the 1940’s and 1950’s were also showcases for new and sometimes customized aircraft. Parachuting and mock dogfights remained popular parts of air show activities.

Литература

1. Grant R.G. Flight 100 years of aviation: Dorling Kindersley Limited A Penguin Company, London, 2002

2. Encyclopedia of FLIGHT Edited by Tracy Irons-Georges: Salem Press, Inc. Pasadena, California, 2002

3. "МАКС" - авиационно-космический салон [Электронный ресурс] URL: http://www.aviasalon.com

4. Какими будут самолеты будущего? Мир науки и техники [Электронный ресурс] URL: http://mirnt.ru/aviation/budushee-aviacii

5. Future of the Super Airliners [Электронный ресурс] URL: http://taa-t.co.za/future-of-the-super-airliners

6. British Airways Extends In-flight Entertainment [Электронный ресурс] URL: http://www.tomshardware.com/news/British-Airways-In-flight-Entertainment-Movies-TV-Shows,19463.html

7. Fly smart [Электронный ресурс] URL: http://honeymoons.about.com/od/flying/tp/fly_smart.htm

8. Boeing 787 [Электронный ресурс] URL: http://www.boeing.com/boeing/commercial/787family/background.page?

9. Самолеты семейства Boeing 737 (Боинг-737) [Электронный ресурс] URL: http://www.airlines-inform.ru/commercial-aircraft/Boeing-737-family.html

10. Starting up a new generation of engines [Электронный ресурс] URL: http://www.boeing.com/Features/2010/05/bca_engine_runs_05_11_10.html

11. Share your opinion about airlines and airports [Электронный ресурс] URL: http://www.airlikes.com/british-airways-reviews

12. Summary writing[Электронный ресурс] URL:http://www.kfmaas.de/summary1.html

13. Future Technology and Aircraft Types [Электронный ресурс] URL: http://adg.stanford.edu/aa241/intro/futureac.html

Наши рекомендации