改变人类的发明(英文版)

One of the greatest inventions that changed our lives —— Airplane

For thousands of years, our ancestors had dreamed to

fly like birds. Finally one day, the dream came true.

Nowadays, we can fly faster than birds, we can fly

further than birds, and we can fly higher than birds. No

matter how far the destination was, no matter it was a

business trip or traveling, we went there by airplanes.

Airplanes have changed our lives. It delivered

convenience to us. Well, here we are.

1.Early history

Cayley's first innovation was to study the basic science of lift by adopting the whirling arm test rig for use in aircraft research and using simple aerodynamic models on the arm, rather than attempting to fly a model of a complete design. In 1799 he set down the concept of the modern airplane as a fixed-wing flying machine with separate systems for lift, propulsion, and control. In 1804 Cayley constructed a

model glider which was the first modern heavier-than-air flying machine,

having the layout of a conventional modern aircraft with an inclined wing

towards the front and adjustable tail at the back with both tailplane and fin. A

movable weight allowed adjustment of the model's center of gravity. In 1848 he

had progressed far enough to construct a glider in the form of a triplane large

and safe enough to carry a child. A local boy was chosen but his name is not

known. He went on to publish in 1852 the design for a full-size manned glider

or "governable parachute" to be launched from a balloon and then to construct

a version capable of launching from the top of a hill, which carried the first adult aviator across Brompton Dale in 1853. At the age of steam, Henson's 1842 design for an aerial steam carriage broke new ground drawing directly from Cayley's work. Although only a design, it was the first in history for a propeller-driven fixed-wing aircraft.

2.The Wright Brothers

Using a methodological approach and

concentrating on the control ability of the

aircraft, the brothers built and tested a series of

kite and glider designs from 1900 to 1902

before attempting to build a powered design. The

gliders worked, but not as well as the Wrights had

expected based on the experiments and writings of

their 19th-century predecessors. Their first glider,

launched in 1900, had only about half the lift they

anticipated. Their second glider, built the following

year, performed even more poorly. As a result, the

Wrights corrected earlier mistakes in calculations

regarding drag and lift. Their testing and

calculating produced a third glider with a higher

aspect ratio and true three-axis control. They flew it

successfully hundreds of times in 1902, and it

performed far better than the previous models. By

using a rigorous system of experimentation,

involving wind-tunnel testing of airfoils and flight

testing of full-size prototypes, the Wrights not only

built a working aircraft, the Wright Flyer, but also helped advance the science of aeronautical engineering.According to the Smithsonian Institution and Fédération Aéronautique Internationale (FAI), the Wrights made the first sustained, controlled, powered heavier-than-air manned flight at Kill Devil Hills, North Carolina, four miles (8 km) south of Kitty Hawk, North Carolina on December 17, 1903.The first flight by Orville Wright, of 120 feet (37 m) in 12 seconds, was recorded in a famous photograph. In the fourth flight of the same day, Wilbur Wright flew 852 feet (260 m) in 59 seconds. The flights were witnessed by three coastal lifesaving crewmen, a local businessman, and a boy from the village, making these the first public flights and the first well-documented ones. The Wrights continued flying at Huffman Prairie near Dayton, Ohio in 1904–05. In May 1904 they introduced the Flyer II, a heavier and improved version of the original Flyer. On June 23, 1905 they first flew a third machine, the Flyer III. After a severe crash on 14 July 1905, they rebuilt the Flyer III and made important design changes. They almost doubled the size of the elevator and rudder and moved them about twice the distance from the wings. They added two fixed vertical vanes (called "blinkers") between the elevators, and gave the wings a very slight dihedral. They disconnected the rudder from the wing-warping control, and as in all future aircraft, placed it on a separate control handle. When flights resumed the results were immediate. The serious pitch instability that hampered Flyers I and II was significantly reduced, so repeated minor crashes were eliminated. Flights with the redesigned Flyer III started lasting over 10 minutes, then 20, then 30. Flyer III became the first practical aircraft (though without wheels and needing a

launching device), flying consistently under full control and bringing its pilot back to the starting point safely and landing without damage. On 5 October 1905, Wilbur flew 24 miles (39 km) in 39 minutes 23 seconds." According to the April 1907 issue of the Scientific American magazine,the Wright brothers seemed to have the most advanced knowledge of heavier-than-air navigation at the time. However, the same magazine issue also claimed that no public flight had been made in the United States before its April 1907 issue. Hence, they devised the Scientific American Aeronautic Trophy in order to encourage the development of a heavier-than-air flying machine.

In conclusion,with the development of science and technology, modern airplanes will be Faster , Higher, and saf er in the future. Thank you!

A Brief Airplane History (Time Line)

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