Category FLIGHT and M ОТІOIM

Then German engineer Anthony Fokker invented a gun with an interrupter gear, which synchronized machine gun bul­lets so that they would shoot between the whirling blades of a propeller. Fokker fighters fitted with these synchronized machine guns went into battle in 1915 and were immediately successful.

Most fighters gave up the two-seat layout and became single-seat pursuit or scout planes. The fastest German fighter of World War I, the Fokker D. VIII, could fly 127 miles per hour (204 kilo­meters per hour). As well as engaging other fighters in aerial battles, or “dog­fights,” fighters attacked enemy bombers and airships. The most successful fighter pilots became known as aces.

Aircraft speeds did not increase dra­matically during the 1920s, and air forces continued to use biplane fighters with open cockpits. These pursuit planes were intended to intercept, chase, and shoot down slower enemy bombers. Engaging equally fast enemy fighters was thought less likely. In the 1930s, new monoplane fighters—such as the German Messerschmitt Bf 109—came into service. They were much faster: around 350 miles per hour (563 kilo­meters per hour). The Bf 109 served

ACE PILOTS

The most successful American fighter ace of World War I was Captain Edward V. Rickenbacker (1890-1973), a former racing driver, who led the first U. S. patrol over German lines in March 1917. Captain Rickenbacker ended the war with twenty-six confirmed victories. Other fighter aces of World War I included Major Edward Mannock (Britain), with seventy-three victories; Manfred, Freiherr von Richthofen, known as the Red Baron (Germany), with eighty; and Captain Paul-Rene Fonck (France) with seventy-five.

During World War II, fighter air­craft were used to support ground attacks as well as to defend territory against enemy bombers. German fighter aces in this war "scored" far more highly than any Allied pilots:

This was because, in the early years of the war, German pilots were opposed by pilots from European countries that were flying in out-of-date aircraft. The leading World War II German fighter ace, Major Erich Hartmann, destroyed 352 enemy aircraft.

throughout World War II (1939-1945) in the German air force (the Luftwaffe) and was used for ground attack as well as air-to-air fighting.

THE MIGHTY MUSTANG

The P-51 Mustang began life as a hastily built fighter for the British, who ordered it in 1940 when they were struggling in the war against Nazi Germany. At 437 miles per hour (703 kilometers per hour), the Mustang was faster than almost any other fighter of World War II. Its exceptional range of over 2,000 miles (3,218 kilometers) allowed it to escort Allied bombers as far as Berlin, Germany. The most popular production version was the P-51D, of which almost 8,000 were built.

or most of the twentieth century— ever since the Wright brothers took to the air in 1903—the prospects for aviation seemed brighter with each passing year. From the start of transcon­tinental passenger flights in the 1930s, through the beginning of the jet age in the 1940s, to supersonic and wide-body air travel in the 1970s, progress was rapid. Air transportation made the world seem smaller, and by the 2000s it had given rise to a billion-dollar tourist industry. Some people thought nothing of flying across the Atlantic Ocean from Europe to America for a weekend’s shopping or from the United States to a Pacific island for a vacation.

Air travel is currently growing at 3 to 5 percent each year, and air cargo trans­portation is growing even faster. New airports are being planned and existing ones made larger to cope with this growth. Increasing numbers of people are taking up sports flying activities, such as gliding, microlight flying, sky­diving, and paragliding. The aviation industry provides many thousands of jobs, especially in the richer countries. In its short history, aviation has trans­formed the world. Can it continue to do so in the future?

Challenges to Airline Travel

The terrorist attacks of September 11, 2001, when airliners were targeted by terrorists, caused a temporary drop in the number of people wanting to fly, especially long-distance. It also led to new security measures to counter the terrorist threat. In the twenty-first century, air passengers will continue to
experience a high level of security checks at airports.

While terrorism may not stop people from flying, environmental concerns will affect the future of aviation. Scientists now highlight carbon emis­sions from airplanes as contributing substantially to global warming. Environmentalists suggest higher fares and cutbacks in airline travel. Some aviation experts favor bigger planes that can carry more people on fewer flights. Others argue that improved, fuel- efficient engines will be the answer. Another problem is noise pollution around airports, although today’s jets are 75 percent quieter than jets were in the 1960s.

Rising costs, especially for jet fuel, will affect the airline industry. There is fierce competition between low-cost airlines, which offer cheaper flights with few extras, and the established long­distance airlines. There may not be room for many small airlines to operate, and the tendency for major airlines to merge is likely to continue.

The first glider competition was held in 1920 in Germany, a nation forbidden to build powered airplanes after its defeat in World War I (1914-1918). German pilots led the way in glider flying, and German manufacturers have remained at the forefront of glider design ever since. In 1922, a German made the first glider flight lasting more than an hour.

Sport gliding became popular in other countries, too. German pilots set

up the first gliding school in the United States at South Wellfleet, Massachusetts, in 1929. The first U. S. gliding champi­onships were held at Elmira, New York, in 1930. Sport gliding is now an inter­national pursuit, with championship competitions for the different classes of gliders.

During World War II, large gliders carrying troops were used by the Germans in their attacks on Belgium in 1940 and on Crete in 1941. Gliders were used by the Allies, too, during the liber­ation of Western Europe in 1944. More
than 300 Allied gliders were used to land assault troops in Normandy, France, during the D-Day landings of June 1944.

The gasoline engine of the 1880s made helicopters possible. In 1907, French inventors Paul Cornu and Louis Breguet built machines that hopped briefly into the air. That same year, a French heli­copter did lift a man off the ground, but only while it was held steady by four men with long poles.

At this time, Russian engineer Igor Sikorsky was also investigating helicop­ters; he built his first in 1910. Meanwhile, in the United States, Emile and Henry Berliner were also building helicopters. None of these machines, however, could fly very well, and they did not rival the fixed-wing aircraft that were developing rapidly in this period.

During the 1920s-1930s, interest in helicopters was spurred by the appear­ance of the autogiro. This was an air­plane with fixed wings and a propeller, with a large four-bladed rotor on top for takeoff, landing, and steering. It demon­strated the advantages of an aircraft that can take off and land vertically-landing in city centers, for example.

During its observations, Hubble has pro­vided some amazing, and often very beautiful, images of galaxies, nebulas, and individual stars. The data it has col­lected has helped to solve some long­standing problems in astronomy.

The telescope has taken pictures of galaxies more than 12 billion light-years away. A light-year is the distance that light travels in a year, so the light that Hubble receives from such distant sources began its journey 12 billion years ago. Hubble has given scientists their most detailed look at the farthest known galaxies in the universe. It has also detected evidence about the atoms present in the atmosphere of a distant planet far beyond our own solar system. Such distant objects are too far away to be visited by a spacecraft, so scientists rely on Hubble for evidence that may answer one of the great questions of modern science: Are there any worlds outside our solar system where the con­ditions for life exist?

SEE ALSO:

• Challenger and Columbia

• Future of Spaceflight • Satellite

• Space Shuttle

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The development of military jets led to new engines for airliners. The first jetliners were introduced in the 1950s. They were used mostly on long-distance air routes across oceans and continents. Their great power enabled jetliners to fly nearly twice as high as the older piston – engine planes. Flying above the worst of the weather, the jetliners gave passen­gers a smoother flight. They also were almost twice as fast as the older air­planes, so journey times were halved. In later years, smaller jet planes were developed for shorter routes.

Modern jet engines are amazingly powerful. The most powerful is the General Electric GE90-115B, developed for the Boeing 777 airliner. This engine produces as much power as ten of the engines that powered the first U. S. jet­liner, the Boeing 707.

Jet power does not always require enormous engines. At the opposite end of the size scale, there are miniature jet engines that are small enough to sit in someone’s hand. Tiny jets like these are powerful enough to propel radio – controlled model aircraft.

Jets in Space

Jet engines do not work in space because they need oxygen in the atmos­phere to burn their fuel, and there is no atmosphere in space. Jet power is used

ift and drag are two of the four forces that act on an airplane. (The other two are thrust and weight.) Lift and drag are aerodynamic forces, which means that they are produced by the effect the shape of an airplane has on the air it is traveling through. Lift is an upward force produced by the shape of an airplane’s wings. Drag is a back­ward force produced by air resisting the movement of an airplane traveling through it. Lift and drag are both vec­tors, or quantities with size and direction.

Lift and drag are closely linked. Lift is necessary for flight, but drag tries to stop a plane from flying by slowing it down. More speed means more lift, but it also means more drag. These two forces are in constant conflict. Lift and drag is useful in determining how effi­cient an airplane is.

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Lift-to-Drag Ratio

To figure out the efficiency of aircraft, designers and engineers use a measure­ment that combines and compares lift and drag. This measurement is called the lift-to-drag ratio. (A ratio is a pair of numbers that show how two quantities are related to each other.)

The lift-to-drag ratio also is known as the L/D ratio, or just “L over D.” It is simply the amount of lift divided by the amount of drag. As the second number of the ratio is usually one, it is some­times omitted and only the first number is given. The better a plane is at produc­ing lots of lift with little drag, the bigger the L/D number is. The best gliders have an L/D of 60 or 70, compared to an air­liner’s L/D of about 15. Birds, such as the albatross, that are good at gliding for long distances, also have a high L/D.

There are three basic types of microlight aircraft. The first type, known as a weight-shift or trike, resembles a pow­ered hang glider. It is basically a glider wing from which a three-wheeled cart is suspended for the pilot to sit in. The

the three-wheeled design. The trike pilot flies the air­plane in a fashion similar to flying a hang glider, con­trolling it with movements of a horizontal handbar and by shifting the position of the body to alter its weight distribution. The lightest weight-shift airplane is a powered hang glider, which is foot- launched (to take off, the pilot simply runs down a slope into the wind). There also are powered parachutes and powered paragliders. As the lightest kinds of micro­lights, these also can be foot-launched.

Larger microlights are air­planes, either three-axis fixed – wing or two-axis fixed-wing. Three-axis fixed-wing micro­lights look and fly more like a full-sized airplane, moving around three axes of control: yaw, pitch, and roll. The pilot uses the same kind of controls as those in a regular airplane: ailerons, elevators, and rudder.

Such microlights are in some respects scaled-down versions of conventional airplanes.

The two-axis fixed-wing is a simpler machine. These air­craft look less like a conven­tional airplane and have no ailerons. For this reason, the pilot must use the rudder when making a turn.

Along with gods and goddesses, mythologies are full of flying creatures, such as the winged horse Pegasus. Dragons are found in legends across the world, and many cultures depict them as having the power to fly.

The Oni of Japan were humanlike flying demons who used their sharp claws to take hold of the spirits of dying people who had led evil lives. Ireland had evil spirits that traveled on the west wind to grab the souls of the dying. Vampires also may fly, either on their own or by turning themselves into bats, depending on the version of the legend.

Some flying creatures were part human and part spirit. The Smaj of Serbia served as the protectors of the Serbian people and could spit fire on enemies from the air. The Kanae of Polynesia changed into flying fish, giv­ing them the ability to travel through water or air.

The Jewish and Christian faiths also include creatures that can fly. The good ones, of course, are angels. The evil ones are demons, who carry out the work of Satan. Not all accounts of these crea­tures give them wings, but they were typically shown that way from the Middle Ages onward.

The mythology of Malaysia provides a different twist. It tells the tale of

PEGASUS AND BELLEROPHON

Bellerophon, a figure of Greek mytho­logy, was a skilled horseman. During his travels, he was given the difficult task of fighting the Chimera, a monstrous beast that was part lion and part dragon. Acting on the suggestion that he use the winged horse Pegasus, Bellerophon placed a golden bridle-given to him by the goddess Athena-on the steed, thereby taming him. Mounted on Pegasus, Bellerophon killed the Chimera.

Bellerophon lived happily for many years until he decided to take another ride on Pegasus. Foolishly, he set his goal as Mount Olympus, home to the gods. Enraged by Bellerophon’s boldness, Zeus sent a fly that bit Pegasus, causing the horse to buck. The sudden move threw Bellerophon from his mount, and he fell toward Earth. Athena prepared a soft landing for him on the ground, prevent­ing his death. Bellerophon was left crip­pled, however, and Pegasus flew away.

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Sheikh Ali, an evil ruler who controlled three armies of flying animals—horses, lions, and elephants.

Mostly, the Night Witches made surprise raids on German supply depots and army camps. They flew by night, and the pilots often shut off their engines when approaching the enemy position so that the planes glided in silently. They restarted the engines just before the attack, dropped their bombs, and disap­peared into the darkness before German troops could open fire.

О A group of female Soviet combat pilots make their flight plans somewhere in the Soviet Union in 1942.

The slow Po-2 biplane appeared to be an easy target for a fast German fighter, such as an Me-109. The top speed of the Soviet biplane, however, was actually less than the minimum (stall) speed of the German fighter. This difference in speed meant that a German fighter chasing a Po-2 often sped past its slow – moving target and had to fly around in a circle for another attack. The skillful Night Witch pilots, meanwhile, flew close to the ground, twisting and turning and even disappearing behind trees. The German fighter pilots did not find it easy to shoot down a Night Witch.

The Russian planes were so small and flew so low that they barely showed up on German radar. In key battles, such as the Battle of Stalingrad in 1942-1943, the Germans mustered searchlights and used heavy antiaircraft guns to blast the Night Witches out of the sky. The pilots of the 588th Regiment flew in threes to outwit this tactic. Two planes flew straight and level, to attract the search­lights, and then they began a series of
aerobatic moves. While the German searchlight crews struggled to hold their light beams on the gyrating biplanes, the third Night Witch moved in to attack. The pilots then regrouped and repeated the attack until all three aircraft had dropped their bombs.

Twenty-three Night Witch pilots received their country’s highest honor in the form of Hero of the Soviet Union medals. Two pilots, Katya Ryabova and Nadya Popova, carried out eighteen raids in one night. In total, the Night Witches flew more than 24,000 missions. Most of the women pilots who survived the war flew hundreds of missions.

SEE ALSO:

• Aerobatics • Biplane • Bomber

• Pilot • World War II

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