Category FLIGHT and M ОТІOIM

Amphibians, designed to land on both water and dry land, are more versatile than regular seaplanes and land-based planes. They are useful in remote regions such as northern Canada and Siberia in Russia, where there are plenty of bays, lakes, and rivers but few cities with airports. Amphibians were as pop­ular as land-based planes during the early years of aviation.

Amphibious airplanes continue to be useful for many tasks. One of the most enduring designs was the Canadian – built Noorduyn Norseman (1935), which is basically a very tough, high-wing
monoplane that could be fitted with wheels, floats, or skis (for snow and ice). Canada also produced the Canadair CL-215 (1966). This aircraft, still used today, was designed as a firefighting amphibian. It has two 600-gallon (2,271- liter) tanks for water scooped up while flying low over a lake or river and then dumped over wildfires. The Grumman Albatross (1947) also has enjoyed a long career as an amphibian, used by the U. S. Air Force and U. S. Coast Guard.

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SEE ALSO:

• Aircraft, Commercial • Aircraft, Military • Curtiss, Glenn • Hughes, Howard • World War II

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Future missions to planets will follow the examples of the Huygens/Cassini mission to Saturn’s moon Titan and Galileo’s voyage to Jupiter’s moon, Europa. Europa is especially interesting to scientists. One ambitious project, called Icepick, plans to send a diving probe to plunge into the waters of the ocean believed by many scientists to lie beneath the surface of Europa.

Such planetary missions take years to plan and years to fly. The European Space Agency’s Rosetta craft, which was launched in 2004, will not reach its tar­get (a comet) until 2014. Messenger,

only the second spacecraft ever sent to Mercury, was launched by the United States in 2005. It will not arrive near Mercury until 2011. NASA also plans to send the Juno probe to explore Jupiter, the biggest planet in the solar system, by 2010.

Scientists would welcome a future, safer method of recovering data from spacecraft after missions. The Genesis spacecraft, launched in 2001, spent 884 days orbiting the Sun, collecting minute particles of the stream of gases known as the “solar wind.” The plan was to return these samples to Earth, using helicopters to recover a capsule landed by para­chute. Unfortunately, the parachutes did not open correctly, and Genesis crashed into the Utah desert in September 2004.

Scientists are eager to extend our knowledge of other planets. They hope to study comets and asteroids and inves­
tigate the myriad stars that lie beyond our solar system. Space scientists are curious to examine the material of which comets are made. They want to explore the planets of the solar system, such as Saturn, which was visited by the Cassini probe in 2004. Above all, scien­tists want to probe the stars for evidence about how the universe was formed and to search around distant stars for Earth­like planets that might contain life.

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SEE ALSO:

• Fuel • NASA • Satellite • Space­flight • Space Probe • Space Shuttle

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ravity is a force of nature that everyone is familiar with. On Earth, gravity is the force that pulls everything downward. It also keeps the Moon in orbit around Earth and the planets in orbit around the Sun. All fly­ing machines must overcome its pull.

Gravity is a property of matter. It is a force that always pulls, never pushes. Every particle of matter has its own tiny force of gravity, which attracts every other particle of matter.

Sir Isaac Newton (1642-1727) made a scientific study of gravity. He discov­ered that the force of gravity between two objects depends on their masses and the distance between them. The greater the masses, Newton’s experiments showed, the stronger the force. Newton also found that the farther apart the masses are, the weaker the force. A big mass such as Earth has a strong force of gravity that gets weaker farther away.

Falling

Objects fall to the ground because of gravity. Common sense seems to suggest that heavy objects should fall faster than light objects, but that is not correct. Galileo Galilei (1564-1642) carried out experiments to show that heavy and light objects fall at exactly the same rate. Another way of saying this is that acceleration due to gravity does not depend on mass. If two lumps of clay, one twice as big as the other, are dropped from the same height, they fall

NEWTON’S UNIVERSAL LAW OF GRAVITATION

Isaac Newton’s Universal Law of Gravitation states that the force of gravity between two masses is directly proportional to the product of their masses and inversely propor­tional to the square of the distance between their centers. The equation that expresses this reads as follows:

F= Gm1m2/d. F is the force of grav­ity; G is the constant of gravitation; m1 is one mass; m2 is the other mass; d is the distance between the centers of the masses.

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at the same rate and hit the ground at the same instant.

Near Earth’s surface, falling objects accelerate due to gravity at about 32 feet per second per second (10 meters per second per second). This means that the object travels 32 feet per second (10 meters per second) faster every second. Objects falling through the air from a great height eventually stop speeding up because the force of gravity is balanced by air resistance pushing upward. The final speed of a falling object is called its terminal velocity.

In Earth’s gravity, if a feather and a hammer are dropped, the feather takes much longer to fall than the hammer.

The feather is so light and it has such a big surface area that its fall is slowed by air resistance much more than that of the hammer. In 1971,

U. S. astronaut David Scott took a feather and a hammer to the Moon and carried out an experiment. Without any air to slow the feather, it fell as fast as the hammer when Scott dropped them both. The two objects landed on the Moon’s sur­face at the same time.

There are very few flying jobs that a helicopter cannot do. A helicopter can pick up a load in one place and deposit it neatly in another. For example, a helicopter can position a communica­tions antenna on top of a skyscraper or lower a roof onto a high structure. Farmers use helicopters to spray crops, and firefighters use them to dump water on forest fires.

Helicopters play a important role in search-and-rescue missions and fre­quently pick up injured mountain climbers. They ferry food, clothing, and medical supplies to the victims of natu­ral disasters (such as earthquakes or hur­ricanes) in hard-to-reach places.

Police use helicopters for surveil­lance, highway patrols, and pursuing criminals. Heads of state use them for security reasons-the presidential heli­copter, for example, lands the president on the White House lawn and within other secured areas. Business executives often prefer to arrive for a business meeting by helicopter to avoid traffic jams. Media organizations, such as TV

SUPERFAST X2

In 2005, Sikorsky Aircraft announced a new, high-speed, rotary-wing air­craft. Known as the X2, this helicop­ter has a coaxial design (two rotors spinning on the same axis) and a "pusher" prop at the tail. X2 technol­ogy does away with the need for a tail rotor, and a coaxial rotor layout also makes the helicopter more sta­ble. The X2 does all the things that ordinary helicopters do, but it flies significantly faster, thanks to its pusher-propulsion. The world record speed for a helicopter is 249.09 miles per hour (400.87 kilometers per hour), set by a Westland Lynx in 1986. Most helicopters cruise at about 185 miles per hour (300 kilo­meters per hour). The X2 designers are claiming speeds of at least 290 miles per hour (470 kilometers per hour) for their latest helicopter.

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stations, send helicopters to cover news stories from the air, and many exciting stunts in movies are filmed from heli­copters. Helicopters are useful for exploring remote areas because they can land just about anywhere. They are used, for example, to track migrating animals, for environmental research, and by util­ity companies for checking power lines.

The attack helicopter is a key weapon of the twenty-first century. The AH-64

Apache attack helicopter, for example, fired the first shots in the 1991 Desert Storm operation during the Iraq War. It used Hellfire missiles to knock out Iraqi radar and surface-to-air missile sites. Helicopters also were used in the Iraq War that began in 2003 and in U. S. combat in Afghanistan. The Apache, and the more recent AH-64D Apache Longbow, are very effective against ground targets. These kind of attack hel­icopters can be linked to a sophisticated command-and-control system, which allows commanders on the ground to call up an air strike on a precise target.

SEE ALSO:

• Aircraft, Military • Autogiro

• Da Vinci, Leonardo • Lift and Drag

• Sikorsky, Igor

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Hindenburg

Type: Dirigible airship.

Manufacturer: Zeppelin Company (Germany).

First flight: 1936.

Use: Long-distance passenger transport.

he LZ 129 Hindenburg was one of several great passenger-carrying airships built between World War I and World War II. It was destroyed on May 6, 1937, while approaching its mooring mast at Lakehurst, New Jersey, after a flight from Frankfurt, Germany.

Zeppelins

The Germans developed large Zeppelin military airships during World War I (1914-1918). The German airship Graf Zeppelin, the most successful commer­cial airship of its time, flew around the world in August 1929. Its commander was Dr. Hugo Eckener (1868-1954), who led the Zeppelin company after the death in 1917 of its founder, Ferdinand von Zeppelin (also known by his title, Graf Zeppelin).

Eckener believed that very large pas­senger airships would rival airplanes. The new super-Zeppelins would cruise over the oceans, like true ships of the air, offering passengers high standards of comfort as well as spectacular views. In 1932, Graf Zeppelin began the first reg­ular transatlantic air service, flying between Germany and Brazil. This airship flew throughout the 1930s, covering more than 1 million miles

(1,600,000 kilometers) without any acci­dents. Its success encouraged airship designers in the United States, Britain, France, and other countries to follow the Zeppelin example.

The 129th airship built by the Zeppelin Company, LZ 129 Hindenburg, took to the air for the first time in March 1936. It was named for Paul von Hindenburg (1847-1934), president of Germany from 1925 until his death. The airship was the pride of Nazi Germany and flew over the Olympic Stadium in Berlin during the 1936 Olympic Games. The Hindenburg and its sister ship, the Graf Zeppelin II, were the largest air­ships ever built.

TECH^TALK

HINDENBURG DESIGN

The Hindenburg was an enormous aircraft. It was almost 804 feet (245 meters) long—as long as a 1930s ocean liner and longer than three Boeing 747 airliners. The airship’s four diesel engines, each producing 1,200 horsepower (890 kilowatts), gave it a maximum speed of 84 miles per hour (135 kilometers per hour).

The Hindenburg was very strongly built. It had a framework made of a metal alloy known as duralumin (a mixture of aluminum and copper with traces of magnesium, man­ganese, iron, and silicon). The gas to lift the giant airship was enclosed in sixteen bags, called cells, within the rigid metal girder frame. The Hindenburg could hold more than 7 million cubic feet (196,000 cubic meters) of gas.

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In the 1980s, the United States, Europe, and the Soviet Union all made plans to build their own space stations. In 1984,

President Ronald Reagan announced that the U. S. space station would be built within ten years. President Bill Clinton ordered a review of the project in the 1990s, however, because of rapidly ris­ing costs. In the end, the United States agreed to share the project with other nations, and the International Space Station project came into existence.

In the early twenty-first century, five national space agencies are involved in the construction and use of the ISS. These are the U. S. National Aeronautics and Space Administration (NASA); the Russian Federal Space Agency (Roskosmos); the Japanese Aerospace Exploration Agency (JAXA); the Canadian Space Agency (CSA); and the European Space Agency (ESA). Russia had continued the Soviet space program when the Soviet Union was dismantled.

Building the ISS

Construction of the ISS requires a series of flights by U. S. Space Shuttles and Russian Proton and Soyuz rockets. More than forty such flights will have been made before the station is finished. Construction is scheduled to be complete by 2010. When completed, the ISS will weigh (in Earth terms) more than 400 tons (363 metric tons). It will be 243 feet (74 meters) long and will have room for six people.

The first two modules of the ISS were the Russian Zarya and the U. S. Unity module. They were launched and joined in 1998, after Space Shuttle Endeavour had flown into orbit carrying two pres­surized adapters to join the modules. Shuttle astronauts captured Zarya and docked it with Unity. The union was the first stage of building the space station.

In July 2000, a Russian Proton rock­et launched the Zvezda service module, which was docked to the station. Space Shuttle missions continued to deliver new pieces, including-in October 2000- the Z1 Truss. This piece of equipment was vital, a large framework for the first set of solar panels and batteries that pro­vide electrical power to the space sta­tion. In December 2000, the first ISS crew fitted the giant solar panels that stick out from the space station like wings. The panels were then connected to the station’s power system.

The construction techniques devel­oped for the ISS could be useful when future astronauts build a Moon base, using similar modules prefabricated on Earth and assembled on the Moon. Technologies used on the ISS also may lead to improved commercial communi­cations systems on Earth.

kite is a lightweight, wing-like aircraft. It is usually flown at the end of a long string held by a person on the ground. A kite is support­ed by the wind which pushes against its surface to provide lift. Stunt kites can fly turns, loops, and other acrobatic maneu­vers. There are various shapes and sizes of kites, from toy kites flown by children to kites big enough to lift a person.

The Chinese were flying kites at least

2,0 years ago and maybe even as long ago as 1000 b. c.e. In 1295, Marco Polo (1254-1324), the first European explorer known to visit China,
reported man-lifting kites there. Box kites were used in experiments by early aviation pioneers. Samuel Cody flew man-lifting kites in the 1890s, and such kites were used for observation over the battlefields of World War I (1914-1918). The Wright brothers also flew kites to test their ideas about airplanes.

Types of Kites

There are several designs of kites. A tra­ditional plane surface, or flat kite, can be made from a long stick with a shorter stick fixed crosswise at a point just above the middle. The cross-shaped frame is covered with paper, plastic, or fabric. A flat kite requires a tail for sta­bility and balance. One end of the long flying line, wound around a reel or hold­er, is fastened to a bridle, which is made from two or more lengths of string tied firmly to the kite frame. A flat kite is best launched into the wind; the person flying the kite unwinds the line and draws it taut before another person toss­es the kite into the air. With a few tugs on the line, the kite should soar upward.

The delta kite is a triangle shape that has a fabric keel instead of a string bri­dle. Delta kites are good stunt fliers. The bow kite is like a plane or flat kite, but has a curved underside, since the cross­stick is bent like an archery bow. A typ­ical bow kite is the diamond-shaped Eddy kite, named for William A. Eddy,

O Kite flying is an important and symbolic tradition in Asia, where beautiful kites have been made for centuries.

BENJAMIN FRANKLIN’S KITE

One of the most famous and danger­ous kite flights was made by American inventor and statesman Benjamin Franklin in 1752. He flew a kite during a thunderstorm, having attached a metal key to the line. Franklin’s inten­tion was to demonstrate that light­ning is a form of electricity. When lightning struck a metal wire on the kite, a charge of electricity flashed down the wet line, and Franklin saw a spark from the key. The experiment had worked, but it was very danger­ous, and Franklin was lucky to have escaped with his life.

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who patented it in 1891. The box kite, invented in 1893 by Lawrence Hargrave from Australia, can be rec­tangular, triangular, or even six­sided. The parafoil kite, invented by Dominic C. Jalbert in 1963, has a parachute-like fabric structure and no rigid frame-it takes shape when it is filled with wind.

Kite flying is a popular pastime all over the world. In Afghanistan, China, and Japan, kite festivals attract large crowds to watch colorful kites in the shapes of birds, butter­flies, dragons, and fish. Musical kites, with reeds or vibrating strings, make whistling or wailing notes in the wind.

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SEE ALSO:

• Hang Glider • Microlight • Wright, Orville and Wilbur

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Kitty Hawk Flyer

Type: Experimental powered glider. Manufacturers: Orville and Wilbur Wright. First flight: December 17, 1903.

Use: Powered and sustained flight carrying a pilot.

he Kitty Hawk Flyer was an air­craft that made history. It was the first airplane to make a controlled, powered flight carrying a human pas­senger. The Flyer was built by two brothers, Orville and Wilbur Wright, and took to the air on December 17, 1903, from sand hills at Kitty Hawk in North Carolina.

Over the next weeks and months, Lindbergh was celebrated in cities across Europe and the Americas. Proclaimed “Lucky Lindy,” he became a world hero. In 1929, he married Anne Morrow. Lindbergh taught her to be a pilot, and she wrote moving books about the expe­rience of flying. Some of that work was based on experiences that the two Lindberghs had flying together to test routes for two airline companies.

Then tragedy struck the family. In May 1932, the couple’s two-year-old son Charles, Jr., was kidnapped from their home. Eventually, the child was found dead. Grief and stress continued for the family through the search for and trial of the kidnapper. Soon after the child’s murderer was executed in 1936,

"WRONG WAY" CORRIGAN

One of the mechanics who worked for Ryan Aircraft—the company that built Lindbergh’s plane—gained fame for his own flying feat. During the 1930s, Douglas Corrigan fitted out a plane to cross the Atlantic Ocean. He hoped to land in Ireland, home to his family’s ancestors. Several times, the U. S. gov­ernment turned down his request for permission to fly, saying that his plane was not safe enough. On July 17, 1938, Corrigan left a New York airfield in a fog.

He was supposed to head west, to California, but he flew east instead. More than 28 hours later, Corrigan landed in Ireland. When questioned, he insisted that the fog made it difficult to read his compass correctly. The feat earned him fame and the nickname “Wrong Way.” Many historians suspect that Corrigan flew east on purpose, but he never admitted to doing so.

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the Lindberghs moved to England to live. The couple had five more children.

During the 1930s, Lindbergh traveled widely to promote aviation. After World War II broke out in 1939, he made many speeches urging the United States to stay out of the war. This activity resulted in a great deal of criticism, and Lindbergh resigned his commission in the U. S. Army Air Corps Reserve. Once the United States did enter World War II in

1941, however, Lindbergh helped the war effort. He consulted with airplane manufacturers, worked as a test pilot, and flew dozens of combat missions.

After the war, Lindbergh continued to promote the growth of aviation by working with the U. S. military and with private airlines. He also helped to obtain funds for scientist Robert Goddard to do his vital work on rocket development. Lindbergh died in Hawaii in 1974, at the age of seventy-two.

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SEE ALSO:

• Barnstorming • Pilot • Rocket

• World War II

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Date of birth: December 29, 1879.

Place of birth: Nice, France.

Died: February 19, 1936.

Major contributions: Led U. S. air forces in World War I; promoted the use of military aircraft.

Awards: Distinguished Service Cross; Distinguished Service Medal;

Congressional Medal of Honor.

he son of a U. S. senator from Wisconsin, Billy Mitchell was 18 years old and still at college when the Spanish-American war began in 1898. He immediately volunteered for the army, entering as a private. His father used his influence to gain Mitchell a commission as an officer. Mitchell was assigned to the Signal Corps, the group that sent messages from one military unit to another. In combat, the young officer showed brav­ery and quick thinking.

World War I

Mitchell remained in the army after the Spanish-American war ended. As early as 1906-just three years after the Wright brothers took the first airplane into the sky-Mitchell predicted that future wars would be fought in the air. In 1912, by then a captain, Mitchell joined the Army General Staff as the youngest officer in that prestigious unit. While in Washington, D. C., Mitchell began his lifelong mission of urging the military to develop air power.

In his spare time, Mitchell learned to fly and gained his pilot’s license. In 1915, he was assigned to the arm of the Signal Corps that was charged with developing a small air force. When the United States entered World War I in 1917, Mitchell was sent to France. He began talking to leading military figures from other nations allied with the United States who were interested in military aircraft. One of them was British gener­al Hugh “Boom” Trenchard. The general argued strongly that air power should play an important role in allied opera­tions. He is credited with advancing the

THE U. S. AIR SERVICE IN WORLD WAR I

When the United States entered World War I, its military air service was very small. The group numbered only 131 officers and about 1,000 enlisted men. It had fewer than 250 aircraft. The only manufacturing company in the country that could produce large quantities of planes belonged to Glenn Curtiss. He pro­duced many of his famous "Jenny" training planes, and they helped the war effort. However, the United States did not produce a single com­bat airplane during the war.

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role of military aircraft and in building Britain’s Royal Air Force.

Mitchell agreed with Trenchard’s ideas, and he went to work to create a U. S. air service. He began building air­fields near places where American troops were stationed. Other officers often found Mitchell’s personality to be brash and annoying, but he was deter­mined to carry out his plan.

Mitchell was put in charge of all Allied aircraft during the Battle of St. Mihiel in September 1918. Mitchell com­manded almost 1,500 planes-at the time, the largest air force ever assem­bled. In another battle later that fall, he sent massed forces of planes to carry out bombing missions.

NASA has achieved an impres­sive record of exploring the Solar System and beyond with unmanned probes, satellites, and space telescopes. In the 1970s, Pioneer 10 and 11 flew past Jupiter and Saturn. They were followed by Voyager 1 and 2, record-breaking probes that made a tour of the outer planets before eventually leav­ing the solar system. In 1976,

NASA landed two Viking spacecraft on the surface of Mars, and these landers sent the first pictures from the surface of the red planet back to Earth.

Not even NASA’s highly trained and experienced engineers are infallible, however. Sometimes spacecraft disap­pear. In 1993, the Mars Observer space­craft disappeared from tracking screens just three days before it was scheduled to go into orbit around Mars. A succes­sor spacecraft, Mars Global Surveyor, made it into orbit safely in 1998.

NASA often has proved itself adapt­able to challenges. After the Hubble Space Telescope was launched in 1990,
scientists discovered that it had a faulty mirror. NASA designed a rescue package to deal with the unexpected problem in such a costly piece of space hardware. The agency sent Shuttle astronauts to correct the fault, which they did, and Hubble began to provide Earth-based astronomers with their clearest view yet of the heavens.

As the airline industry grew in the 1920s and 1930s, barnstormers and air racers often became commercial pilots. Some of them entered the military. During World War II (1939-1945), many mili­tary pilots learned to fly straight out of college and were often pitched into combat after only a few weeks of train­ing. Fighter pilots in particular earned hero status. Most combat pilots were men, while female pilots delivered air­planes from factories and transported soldiers. After the war, test pilots broke new ground flying the jet – and rocket – powered planes of the supersonic era. Most of the first astronauts selected in the 1960s for the U. S. space program were ex-test pilots.

By the 1970s, with air traffic growing rapidly, the job of the commercial pilot became more demanding. Men still dominated the cockpit, but a few women started flying airliners. Ruth Nichols flew commercial planes as early as 1932. The first regular woman pilot for a U. S. scheduled airline was Emily Warner, who piloted Boeing 737s for Frontier Airlines in 1973. By the end of the twen­tieth century, military forces had women stationed alongside men in combat. The first American woman pilot to drop bombs in combat was Lieutenant Kendra Williams of the U. S. Navy, during Operation Desert Fox in Iraq (1998).