Air travel has become a routine matter these days it is fast, comfortable and safe mode of travel. It takes only a few hours to go to a place thousands of miles away. But there is not much excitement in it as one cannot see much of world as one sits in a place hurtling across the sky at about 600 miles an hour at height of miles or more from the ground.
Endeavours to fly have been made by man since long. The first person go up was a Frenchman Pilare de Rozier, who rose in a hot air balloon on 15th October 1783. He had another person with him who straw to the fire which filled the balloon with hot air. The same year on 1st December two other Frenchmen went up in a balloon filled with hydrogen which is lightest of all gases.
The balloon flights were quite an important step towards the invention of airship. But balloons found to be useless for this purpose unless they were made navigable. Aircrews or propellers were suggested for this purpose but they needed motive power much stronger than human arms could provide. The solution was to be sought in the use of mechanical power. An Englishman achieved a remarkable success in this line in 1884. He used a steam engine to provide this motive power. However, he installed this engine not in a balloon but in a heavier than air machine which type is known as an aeroplane. In 1852 a Frenchman installed to steam engine in airship works engineers. Renard and Krebs used electric power in their airship heavy. The solution was provided by the invention of the internal combustion engine in 1875 by a German named Otto. This piston-driven engine was worked first with coal gas, then with vapourized petrol. In 1886 Wolfert a German installed this engine in an airship. This greatest airship designer was Count Von Zeppelins whose first petrol airship was
manufactured in 1900. These airships were later known as Zeppelins and with them the German bombed London during the First World War.
Work on the heavier then air machines as envisaged by Sring-fellow in 1848 was going on along side of these developments. An American Tangley flew a model in 1896 but was successful with a full-
fledged aeroplane. Two American brothers, Wilbur and Orvile Wright, studied the working of gliders which are engine
less aeroplanes. The petrol engine had assured them of power and now they wanted to learn the way to control these machines. They made a number of attempts and were successful on the fourteen attempts, which was on 17th December 1908 with the brother Orvile flying the machine. Development in this line continued and in 1909 a Frenchman named Bleriot designed an aeroplane in which he successfully flew across the English Channel.
A rapid development in the design of manufacture of aircraft took place during the First World War. When the German used their Zeppeline airships to bomb London the need for defence against them led to intensified research in such aeroplanes as could fly a high speed at a great height. This led to the successful development of fighter planes in 1916. Ever since then, the development of planes has been in the directions of achieving high speed and high altitude.
Airships were begun to be used after the First World War manufactured for the purpose. The hanger at Karachi is a relic of those days. But in the nineteenth thirties they met with such disasters that t hey were given up as a hopeless line. Attention was then concentrated on the development of aeroplanes. Regular air services had come into operation by the time the Second World War started. During the war, these piston-engined aeroplanes were fully developed, and after the war airlines were built which could fly non-stop at about 200 miles an hour. The latest development has taken place on two lines. One of these concerns is a bid to avoid collisions. This has been made quite easy with the invention of radar, which is a device to detect others, aircraft in the course of their flight. The second development concerns a new type of engine. This is called the jet engine. It can fly aeroplanes safely at a speed up to 600 miles an hour.
The next problem for air navigation is to cross the sound barrier. Civil aircraft, able to fly at speed of more that 720 miles per hour have yet to be made. There is every hope that in a few years time, air travel speeds of about 2,000 miles an hour will become a routine matter.
QUESTIONS AND ANSWERS:
Q.1 When, where and by whom was the first aerial journey made?
Ans. A Frenchman, Pilatre de Rozier made the first aerial journey over Paris, on 15th October 1783.
Q.2 What is the essential difference between an airship and aeroplane?
Ans. An airship is a lighter than air machine, while an aeroplane is heavier that air machine.
Q.3 Who invented the internal combustion engine? Why was this type of engine so important to the development of flight?
Ans. A German named Otto invented the internal combustion engine in 1876.
Q.4 Who was the first man to fly in an aeroplane? What was the date of his flight and how long did it last?
Ans. The first man to fly in an aeroplane, i.e. in heavier than air machine was the American, Orville Wright. He flew on 17th December 1903. He stayed in the air for twelve seconds.
Q.5 What, in brief are the respective functions of the reconnaissance aeroplane and the fighter?
Ans. A reconnaissance plane is being used to survey the enemy territory while a fighter is built to shoot down enemy bombers on its territory.
Q.6. How were the first bombing attacks on London made?
Ans. The type of German airships called Zeppelins made the first bombing attacks on London during the World War 1.
Q.7. How did civil aviation benefit from the rapid development of the bomber during the First World War?
Ans. Bombing attacks by airship turned the attention of governments and people to the development of the fighter aircraft because anti-aircraft guns and not proved very effective. This necessitated research into high speed and high altitude flights, and led to the rapid development of aircraft manufacture.
Q.8 Why was it more difficult to fly from Europe to North America than from North America to Europe?
Ans. Flying across the Atlantic was more difficult from Europe to North America than the other way round because on the west bound flight the aircraft had to make a tremendous struggle against head winds and stood in danger of running out of fuel.
Q.9 Why was the use of passenger transport abandoned?
Ans. The use of passenger transport was abandoned in favour of aircraft because they had proved to be very unreliable.
Q.10 What new means of propulsion has greatly increased the speed of airlines in recent years? What kind of radio device contributes to their safety?
Ans. Jet propulsion has greatly increased the speed of airlines in recent years. Radar is the wonderful radio device that contributes to the safety of air travel by making it possible to avoid collisions.