Category FLIGHT and M ОТІOIM

The United States and the Soviet Union tested anti-satellite (ASAT) missile systems back in the 1980s. In 1985, a U. S. F-15 fighter fired a missile that flew into space and destroyed a U. S. solar observa­tory satellite orbiting 375 miles (600 kilometers) from Earth. After this one suc­cess, the ASAT project was abandoned, partly because of concerns that such mis­siles violated the 1967 Outer Space Treaty. The treaty requires nations to refrain from placing weapons into space-such as nuclear warheads, lasers, and other high – energy weapons-that could be used to destroy satellites or aimed at ground targets. In 2007, China claimed to have test-fired a missile that destroyed an obsolete weather satellite, raising a new debate about ASAT usage. As increasing numbers of satellites are launched, the question of how to regulate ASAT systems remains unresolved.

in wilderness and cities. Space cameras provide images from which mapmakers create accurate maps. They even can give computer users instant images of their own location over the Internet.

Weather satellites have revolution­ized meteorology. They provide the daily TV weather images, and they alert fore­casters to developing global weather situations, such as hurricanes. The National Oceanic and Atmospheric Administration (NOAA) runs a national weather service from satellite data pro­vided by the National Environmental Satellite Data and Information Service.

Short-range weather forecasting uses data from geostationary operational environmental satellites (GOES). Long – range weather forecasts use data from polar-orbiting operational environmen­tal satellites (POES). NOAA also operates a search-and-rescue satellite-aided tracking system, known as SARSAT,
which can locate a person in trouble at almost any location on the planet.

kyjacking is the illegal seizure of an airplane. It is a crime similar to hijacking a truck or taking over a ship at sea. Skyjackers may demand that the plane be flown to a destination of their choice or demand a ransom for the release of passengers. They may use the airplane as a weapon of destruction.

How Skyjacking Began

The first recorded skyjacking was in 1931 in Peru. Rebel soldiers forced two American pilots to fly a plane over the city of Lima to drop propaganda leaflets. The first skyjack in the United States

DISAPPEARING AIR PIRATE

Probably the most famous criminal sky­jacking in the United States happened in 1971. A man known as Dan or D. B. Cooper took over a Northwest Orient Airlines Boeing 727. After forcing the plane to land, he demanded $200,000 as ransom for the release of the passen­gers. When he had received the money and four parachutes (one each for him­self and the three remaining crew mem­bers), Cooper ordered the airplane to take off again. He parachuted from the rear of the Boeing 727 over the Cascade Mountains of the northwestern United States and was never seen again. There have been many suspects, but no certain culprit has ever been found.

_________________________________________________ /

took place in 1961, when a passenger on a commercial flight from Miami to Key West, Florida, ordered the pilot to divert the aircraft to Communist-ruled Cuba.

With lax security at airports in the 1960s, it was relative­ly easy for a terrorist to smuggle a gun onto an air­liner to threaten the pilots and passengers. Skyjackers often had political motives.

Taking over an airliner ensured publicity for their cause. Less often, a skyjacker was a criminal who hoped to extort money by air piracy.

In the 1970s, when tension between Israel and its Arab neighbors was high, terrorists based in the Middle East made several attacks on airliners. Their usual practice was to seize an airliner in flight, force the pilot to land, and then broad­cast their demands by radio. Skyjackers held passengers inside the airplane as hostages, hoping to bargain for the release from jail of fellow terrorists or other prisoners.

In September 1970, a spectacular skyjacking took place in the Middle East, when Palestinian terrorists seized three airliners simultaneously. All three air­craft were landed in the Jordan desert at Dawson’s Field (a former British air force base) and then blown up after most of the hostages had been released. An attack on a fourth airplane was foiled by Israeli security guards. A fifth airplane was hijacked three days later.

Meanwhile, the airplane took the lead. When Giffard was making the first airship flight in France in 1852, Englishman George Cayley had already begun a scientific study of the forces produced by moving air, or aerodynam­ics. Cayley was interested in how these forces could be used by heavier-than-air flying machines.

He wrote that the challenge was “to make a surface support a given weight
by the application of power to the resist­ance of air.” He was talking about lift and drag, the aerodynamic forces that act on aircraft. Cayley’s work resulted in the first manned gliders in the middle of the nineteenth century.

The invention of the steam engine in the nineteenth century awakened interest in developing steam-powered airplanes. The steam engines of the day were too heavy, however. Powered air­planes had to wait until smaller, lighter engines powered by gasoline were developed in the late 1800s. That would

О The Giffard steam-powered balloon made the first successful powered flight. The engine, pro­peller, and platform for the pilot hang beneath the 144-foot (44-meter) hydrogen-filled balloon. This model of Giffard’s balloon is now on display at the Science Museum in London, England.

lead to a usable engine for airplanes. Aeronautical pioneers, meanwhile, con­centrated on learning to build stable gliders and control them in the air.

The brothers Orville and Wilbur Wright experimented with kites and gliders in a very methodical way. Each time they encountered a problem, they worked at it until they found a solution. They also designed a gasoline engine light enough to power an airplane based on one of their gliders. The brothers were finally ready to fly the world’s first successful powered airplane in 1903.

The Wright brothers had developed the airplane and shown that controlled flight was possible. Other engineers and inventors reshaped the airplane and otherwise improved it with their own ideas. The age of modern aeronautics had begun.

Otto Lilienthal (1848-1896) in Germany made more than 2,000 glider flights. Other aeronautical engineers and inventors around the world avidly read Lilienthal’s books and essays on aeronautics. The read­ers included Percy Pilcher in Britain and the Wright brothers and Octave Chanute in the United States. These innovators flew gliders similar to modern hang gliders. They steered by shifting their weight to one side.

Aeronautical research at that time was very risky, and accidents were common. Flimsy aircraft made of wood and fabric could fall apart, or they could spin out of control and plunge to the ground. Lilienthal and Pilcher both died as a result of aircraft crashes.

4_______________ J

Into the Modern World

The fixed-wing aircraft was not the only way to fly. Other aeronautical engineers struggled with the problems of building craft with spinning wings, called rotors. Their work led to the development of autogiros and helicopters.

All sorts of new technologies were applied to the airplane-new wing shapes, new engines, metal structures instead of wood, monoplanes instead of biplanes, more efficient propellers, more streamlined aerodynamics, and so on. Piece by piece, these and many other advances in aeronautics transformed the fragile wood-and-wire flying machines of the early twentieth century into the amazing aircraft we have today.

An ACV is an aircraft only in the sense that it is lifted off the surface supported by the air beneath it. Air can exert a lot of power when it is under pressure, for example when it is blasted into an enclosed space. An ACV uses this power to lift itself, floating on a cushion of air created by powerful fans. In this way, it is able to move smoothly over land or water. An ACV cannot fly at height. Depending on the vehicle, the amount of lift is between 6 inches and 100 inches (15.2 centimeters and 254 centimeters).

Some ACVs have wings, designed to generate just enough lift to raise the vehicle above the surface when it has reached a sufficient speed. Wings are not essential, however. An ACV will float on the compressed air that is sucked in by the fans and held in place beneath it. The air is contained either by a rigid sidewall or by a flexible skirt fixed around the lower edges of the vehicle. It is this air that gives the ACV its lift.

For forward propulsion, some ACVs use propellers turning in the air (like some airplanes). Others are driven for­ward by propellers turning underwater or by a high-powered water jet.

О This diagram shows the basic parts of a hovercraft. A fan sucks in air to create lift.

A propeller creates the thrust to move the craft forward, while a rudder is used to steer.

EXPERIMENTING WITH GROUND EFFECT

The principle of ground-effect flight was first suggested in 1716 by Swedish scientist and philoso­pher Emanuel Swedenborg. In the 1870s, British engineer Sir John Thornycroft experimented with model vehicles that floated on air.

He concluded that, instead of a ship having a conventional sealed hull, it could be designed with a plenum chamber-a box filled with air and open at the bottom. (A plenum is an enclosed space in which the air pressure is greater than the air pressure that surrounds the space.)

The air would reduce the drag from the water, allowing the ship to travel faster on less power. Unfortunately, the technology required to build a full-sized ACV did not exist at the time. In the 1920s, however, German engineers proved that a flying boat could achieve greater range and speed by flying very close to the water, making use of ground effect.

____________________________________________ /

ACV Pioneers

The modern ACV owes much to the pio­neer work of three inventors: British engineer Christopher Cockerell and two Americans: airspace engineer Walter A. Crowley and U. S. Navy designer Colonel

Melville Beardsley. Cockerell had the idea that a vehicle would float on a ring-shaped curtain of air. He proved it with experiments using two empty coffee cans and a hair dryer. Crowley, meanwhile, was inspired by his dis­covery that a household lampshade could be made to float on air. In 1957 he built a hover-chair, which was not unlike a giant lampshade. He and Beardsley separately came up with the invention of a flexible skirt to stop air from escaping beneath the ACV. This escaped air had been the chief weakness of Cockerell’s design.

A skirt was fitted to the first practical ACV, Cockerell’s SR-N1 hovercraft. Big enough to carry three men, this vehicle crossed the English Channel in 1959. The SR-N1 skimmed across the sea at almost 30 miles per hour (48 kilo­meters per hour). It offered the prospect of an entirely new kind of ferry.

Experimental

n experimental aircraft is one that is designed to try out new ideas and investigate unknown areas of flight. It may have been designed to fly faster or higher than existing types. It may have been built to test a new wing shape, control system, or engine. Experimental aircraft, often identified as X-planes, sometimes look unlike any airplane flown before.

Many experimental aircraft are intended for military use. The military is constantly looking for new ideas, per­haps to combat a new threat or to take advantage of a new technology. Civil airliners, cargo planes, and light aircraft change less dramatically.

Every new aircraft is to some degree experimental, no matter how much test­ing and computer simulation has been done. The preflight design stage and
ground test program may last several years, but the moment of truth comes when a test pilot flies a new airplane for the first time. Sometimes, experimental craft succeed beyond expectations. A new production line of airplanes may follow. Others are failures. The history of aviation is littered with planes that crashed the first time they were flown. Yet even a failure has its uses, because good designers can learn from mistakes.

Many of the designers and engineers who designed and built their own air­planes in the early days of aviation went on to start aircraft manufacturing com­panies of their own. As soon as the Wright brothers had designed a success­ful airplane, they set up a company to sell the original model and later designs. Other designers did the same.

Many of these pioneering names have disappeared now. The companies went out of business or were taken over by rivals, but a few still exist. Famous

SKUNK WORKS

Skunk Works is a legendary name in aircraft design. It is a small team of designers who specialize in produc­ing very advanced aircraft. Part of the airplane manufacturer Lockheed Martin, Skunk Works produced the high-flying U-2 spy plane and the SR-71 Blackbird spy plane. The Blackbird holds the official world air speed record of 2,193 miles per hour (3,529 kilometers per hour)-nearly four times the speed of a Boeing 747. Most planes would actually melt if they tried to fly that fast. The Skunk Works also produced the F-117 Nighthawk, a military aircraft that is very hard for an enemy to detect. The F-117 is often wrongly referred to as the "stealth fighter," but it is not a fighter, because it was not designed for combat with other aircraft. The F-117 is a ground attack plane-a small bomber intended to attack heavily defended targets.

_____________________________________________ /

THE FEW

rWS MEMORIAL

DURING THE BATTLE OF BRITAIN AND SOARED IN imfd AT UCSTROVINO THE RQ4^ *^L

П4Л hitlers ‘wftwaffejH^Sel assaultsу*тнЕЕо£и5л^1 army and navy оит"™”^”ц°от’“т^

А’ * MET THE Ai■"«£«“’ADA ^ШС^ДА^ОЇ ^ ^ ^

. г, r AFTER NIGH 1. TO ENSURE GREAT BRITAIN’S Ч**Х%1%Ч*Г\/А L BY AraCRAFT. THERFBV tORCWO CHIITUNC LOSSES ON THE LUFTWAFFE. DESTROYING OVER 1880 ENEMY r A E LOSSES WERE DISFROVORT’

/ •■»«!ION PLANS OF THE BRITISH ISLES ALTHOUGH FEWER IN NUMBER. THE RA_.L ыкдкИ*»“’

танк иORE THAN SJO AIRMEN PAID THE ULTIMATE SACRIFICE. SOME EVEN ”,

OWN GUNS JAMMED OR AMMUNITION RAN OU I ІІЕО

AFTER I HE BATTLE. THE BRITISH PRIME MINISTER SIR WINSTON CHURCHRCWJ^ WORDS’

THOSE AIRMEN THAT FI EW DURING THE BATTLE OF BRITAIN WITH THV. Ю SULL SAT

IF THE BRITISH EMPIRE AND ITS COMMONWEALTH LAST FOR Л THOUSAND YEARS. M

THIS WAS THEIR FINEST HOUR’

„r DEDICATED BY Л__лк,

HF BATTLE OF BRITAIN FIGHTER ASSOC! AT AND THE 48TH FIGHTER WING SATURDAY 12TH JULY 1997

aircraft designers and aeronautical engi­neers who started U. S. companies include Glenn Curtiss, Jack Northrop, Donald Douglas, and Igor Sikorsky. William Boeing started an aiplane manufacturing company in the United States in 1916. Today, Boeing is the world’s biggest aircraft manufacturer, employing more than 150,000 people.

In other countries, early aircraft designers include Hugo Junkers and Willy Messerschmitt in Germany; Geoffrey De Havilland in Britain; Louis Bleriot in France; and Pavel Sukhoi, Artem Mikoyan, and Mikhail Gurevich in Russia. (Mikoyan-Gurevich planes are better known as MiGs.)

О Reginald J. Mitchell’s prize-winning Supermarine aircraft design was the basis for the British Spitfire fighter plane of World War II. This Spitfire stands as a monument in the Battle of Britain Memorial Park in the United Kingdom.

The two made good time, aided by a tailwind that helped push them along. Nevertheless, they had many difficulties. The airplane flew in dense fog for most of the flight, making it impossible for Brown to use his navigational instru­ments to track their position or chart a course. Unable to see, Alcock had no idea where he was in relation to the water below. Once, they broke through the clouds to find themselves danger­ously close to the surface of the ocean, and Alcock had to climb quickly.

Storms posed a problem as well. Alcock and Brown flew through sleet that chilled them in their open cockpit.

The icy rain also froze the instrument that told the plane’s speed. Not knowing how fast they were going hampered Brown’s efforts to plot their position. Ice coated the sides of the plane for many hours. Some accounts of the flight say that Brown climbed out on the wings to clear off the ice, but he never claimed to have done so.

Communication became impossible during the flight. The radio they carried gave out soon after taking off. Later, the two phones they used to speak to each other over the roar of the engines also
stopped working. After that, they relied on hand signals and written notes.

About 15 hours after leaving the coast of Newfoundland behind them, Alcock and Brown believed they were nearing their destination in Ireland, but they could not be sure. Soon after, they spotted land. Seeing what appeared to be an open field, Alcock guided the air­plane down. The landing was gentle, but what they thought was a grassy field was really a bog (an area of wet, spongy ground). The front of the plane sank in and tipped forward, causing damage. Alcock and Brown were unhurt, however.

Alcock and Brown had landed near Clifden, Ireland. Remarkably, they were only about 60 miles (96 kilometers) from their intended landing spot. They had flown about 1,900 miles (3,060 kilometers) in approximately 17 hours. The historic first crossing of the Atlantic Ocean by plane was complete.

Spaceflight has a good safety record, but there have been fatal accidents involv­ing astronauts. The first person to be killed during a mission was Soviet cos­monaut Vladimir Komarov in April 1967. Veteran of an earlier flight in the three-man Voskhod 1, Komarov was fly­ing alone in the new Soyuz craft in 1967. It seems the spacecraft began to spin while still in orbit and then over­heated when trying to reenter the atmosphere. Komarov was killed during reentry.

Three U. S. astronauts were trapped and killed in the Apollo 1 fire during ground tests in January 1967. They were Gus Grissom, Ed White (the first American to “walk” in space, in June 1965), and Roger Chaffee.

The worst fatalities to U. S. astronauts involved the Space Shuttle, first flown with astronauts on board in 1981. On January 28, 1986, the Space Shuttle Challenger broke up shortly after liftoff. All seven astronauts were killed. After modifications, the Space Shuttle returned to space, but tragedy struck again on February 1, 2003. This time it was Columbia, nearing completion of its twenty-eighth mission. During its descent, the spacecraft disintegrated high above Texas. Again, all seven astronauts on board died.

Astronauts do not appear to suffer any serious health consequences from short flights. Over time, however, the absence of gravity affects the human body. Astronauts find that their muscles

waste and bones weaken during flights lasting weeks or months. Cosmonaut Yuri Romanenko returned to Earth in 1987 after 326 days in space, aboard the Soviet space station Mir. He found his calf muscles had shrunk 15 percent in spite of workouts on a treadmill and exercise bike.

During periods of prolonged weight­lessness, astronauts grow 1 to 2 inches (2.5 to 5 centimeters) taller because the bones in their spines spread apart. Back on Earth, the bones close up again, and the astronauts soon return to their normal height.

After World War I ended in 1918, there were a lot of ex-military planes for sale and plenty of veter­an pilots looking for jobs. Some of these pilots took up stunt flying and became barnstormers.

The most popular plane they flew was the Curtiss JN-4 Jenny, a wartime training airplane. Pilots could buy a Jenny and fly wherever they wanted to offer flying displays and rides.

Groups of pilots formed traveling shows, or flying circuses. Well-known groups included Jimmy Angel’s Flying Circus, the Five Blackbirds, the Flying Aces, and the Ivan Gates Flying Circus. Ivan Gates toured the United States and hired daring fliers such as Clyde “Upside-Down” Pangborn and Diavalo, “Supreme Daredevil of the Air.” Women barnstormers included Bessie Coleman, the first African American woman pilot; Gladys Ingle, who shot arrows from a bow while wing walking; and Mabel (or Mable) Cody, whose specialty was danc­ing on the wing. Charles Lindbergh, the first person to fly the Atlantic solo, and Wiley Post, the first to fly around the world solo, both spent time flying as barnstorming pilots.

Barnstorming made some pilots wealthy, but it was a tough, dangerous life. Finding fuel and parts for airplanes was not easy in rural areas, and planes
were not always safe to fly. Pilots trav­eled long distances, often going without sleep for days at a time. There were fatal accidents. Bessie Coleman was killed while practicing for a show. Lincoln Beachey crashed into the San Francisco harbor, and Ormer Locklear was killed flying a stunt for a Hollywood movie.

In 1927, the federal government tightened aviation laws to stop danger­ous stunts and make sure that airplanes were properly maintained. The supply of cheap Jenny planes dried up, and the barnstorming era came to an end. Aerobatics and wing walking, however, can still be seen today at air shows.

SEE ALSO:

• Aerobatics • Coleman, Bessie

• Curtiss, Glenn • Lindbergh, Charles

_____________________________________________ J

Bell X-1

Type: Rocket-powered research airplane.

Manufacturer: Bell Aircraft Corporation. First flights: January 19, 1946. (unpowered); December 9, 1946 (powered).

Primary use: Supersonic testing.

he Bell X-1 was the first piloted aircraft to fly faster than the speed of sound in level flight. The flight took place on October 14, 1947.

Landing can be tricky, especially if a bird is aiming to perch on a twig or tele­phone wire. To slow down, a bird uses its tail as a brake, spreading the tail feath­ers to increase drag. Its body adopts an upright position, and the legs swing forward to absorb the shock of impact, just as an airliner lowers its landing gear. The bird beats its wings to main­tain control and uses backbeats (similar to an airline pilot using reverse thrust on a plane’s engines) to slow down. Its feet reach out to get a firm grip on the chosen landing place.

Bigger birds often take a step or two on landing to regain balance, folding their wings as they complete the land­ing. Water birds come down rather like seaplanes, using their feet as water skis as the water slows them down. Some birds, such as fulmars and albatrosses, spent most of their lives flying over the ocean-even sleeping on the wing-and come to land only to breed.

Hunting birds use a variety of differ­ent techniques to descend when they are hunting prey. A buzzard flies high in
circles before swooping down to attack. A peregrine falcon launches itself on its target in a high-speed dive while it folds in its wings to reduce wind resistance. Some birds, such as gannets and boo­bies, dive straight into the ocean to catch fish.