Category FLIGHT and M ОТІOIM

Some birds have as few as 900 feathers, while others have more than 25,000. This does not make much difference in their flying skills. The secret of flying is the bird skeleton. Bird bones are very light, but very strong-many bird bones are hollow. Because the bones are also fused (joined together), a bird has an amazingly strong frame, although it weighs little. Even the world’s heaviest flying bird-a bustard-weighs only 40 pounds (18.2 kilograms).

The largest muscles in a bird’s body work the wings (although in flightless birds, such as the ostrich, these big muscles work the legs). The wing muscles are in the chest, below the wing. The muscles are attached to the upper wing by tendons that work like pulleys. This streamlined body design gives the bird a high power-to-weight ratio, just like an aerobatic airplane. Its muscles provide the engine power to drive the wings. To fuel those muscles, most birds need a lot of food every day. Birds can inhale large amounts of air very quickly, using the oxygen to help provide energy for rapid flight.

A bird’s wings are equivalent to a person’s arms, with long “finger” bones carrying flight feathers, the longest feathers. The bird wing is curved like an airplane wing-slightly rounded on top, flatter underneath. This curved shape forces air to speed up when flowing over the top surface. The faster the airflow, the less air pressure there is above the wing. Because high-pressure air always moves to fill low-pressure space, the air beneath the wing moves upward. This movement creates lift beneath the wing, and the bird flies.

Wing shapes are a clue to how differ­ent birds fly. Fast-flying birds, such

as swifts and swallows, have long, narrow wings, often swept back like a jet fighter. Soaring birds, such as vultures and buzzards, have broad wings. Gliders-the alba­tross, for example-have long, straight wings.

Birds that need rapid takeoffs (like pheasants and prairie hens) and small birds that nest in shrubs or undergrowth usually have quite short, stubby wings.

In the late 1960s, Boeing produced new jet airliners for short – or medium-range flights—the 727 (1964) and the 737 (1968). These were smaller aircraft that were economical for airlines and able to operate from smaller airports.

After failing to win a government contract for a very large military trans­port, Boeing switched to building a giant passenger carrier. This new plane, the 747, had a distinctive “bubble” front, providing an upper deck for first-class passengers. It could seat about 400 passengers in its spacious main cabin, which was 185 feet (56 meters) long and 20 feet (6 meters) wide.

The 747 made long-haul flying much cheaper. Two 747 flights could replace up to ten flights by smaller airliners. Airport passenger handling facilities were strained at first, however, when

TECH*fcT ALK

BOEING AIRLINERS

Boeing’s family of commercial aircraft is designed for different routes. The vari­ous aircraft have ranges of between

2,0 miles (3,220 kilometers) and 9,000 miles (14,480 kilometers). A 777 can fly nonstop from New York to Jakarta in Indonesia. The seat capacities of recent Boeing models are:

• 737 up to 180 seats.

• 747 up to 416 seats.

• 767 up to 245 seats.

• 777 up to 368 seats.

• 787 up to 330 seats.

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two or three 747s landed at about the same time, unloading more than 1,000 passengers within minutes.

Boeing continues to build new airlin­ers. The 757, 767, and 777 were followed by the 787, the latest addition to the line. Each aircraft is designed to fit into a niche in the world air transportation market. Boeing also continues its research into new areas of aerospace through experimental aircraft, such as the X-43 hypersonic airplane.

SEE ALSO:

• Aerospace Manufacturing Industry

• Aircraft, Commercial • Aircraft, Experimental • Aircraft Design

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Dates of birth: Leila Marie: unknown; Samuel: March 6, 1867.

Places of birth: Leila Marie: unknown; Samuel: Davenport, Iowa.

Died: Leila Marie: February 5, 1939; Samuel: August 7, 1913.

Major contributions: Leila Marie: first woman to pilot a heavier-than-air craft; Samuel: inventor of the man-lifting kite and first person to fly an airplane in Britain.

amuel Franklin Cody was born Franklin Samuel Cowdery. He learned how to ride, shoot, and rope, and he joined a Wild West show soon after he turned twenty. About that time, he changed his name to Samuel Franklin Cody.

In 1890 Cody went to Europe to per­form. Soon after, he met Leila Marie Davis. By the late 1890s, Samuel and Leila Marie and her children—whom Cody adopted—were touring together. Leila Maire and her children took Cody’s name, and the couple worked together as partners in demonstrations of trick riding and sharp shooting.

At some point, Cody became inter­ested in flying kites. In about 1900 he developed a system he called his “man­lifting kite.” It included a pilot kite mounted at the top of a long cable; sev­eral lifter kites spaced along the cable; and a carrier kite, from which dangled a basket that could carry a person.

FALSE CLAIMS

By changing his name, Samuel Franklin Cody tried to advance his career by linking himself to William "Buffalo Bill" Cody, who led the most famous of all Wild West shows. He even claimed to be the famous Cody’s son until Buffalo Bill’s lawyers forced him to stop. Cody invented many stories about his early life to appear more colorful. Although widely accepted at the time, they are now known to be fictitious.

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Cody told the British army that his kites could be used to send officers into the sky to make observations of enemy troops. As a demonstration, Leila Marie Cody bravely went up in the kite in 1902, making her the first woman pilot of a heavier-than-air craft. Samuel Cody’s kite ascents finally convinced the army—it hired him as its chief kite instructor in 1905. Working at a military base, Cody continued his flights. In one ascent, an army officer was lifted more than 3,300 feet (1,006 meters) above the ground.

Cody also developed an interest in other kinds of flying. In 1905 he built a glider that traveled more than 740 feet (226 meters). Next he tried putting a motor on a kite, but that effort failed. Cody then worked with Colonel John Edward Clapper to build an airship. On

September 30, 1907, they had a successful 12-mile (19 kilo­meter) flight. Five days later,

Cody and Clapper flew the airship to and around London, thrilling thousands of onlookers.

Samuel Cody’s first air­plane flew on October 16,

1908. Although the flight lasted less than half a minute,

Cody became the first person to fly a plane in Britain and an instant national hero.

Cody continued experi­menting with aircraft, trying out new designs each time one of his flying machines crashed. He became a British citizen so that he could partici­pate in exhibitions and races open only to British citizens. On a 1910 flight, he set a record for the longest British flight in terms of both time (almost 5 hours) and distance—more than 185 miles (298 kilometers).

Cody’s next challenge was the reward offered by the Daily Mail news­paper to the first person to fly a circle around Britain, a distance of more than 1,000 miles (1,600 kilometers). In 1911, Cody beat eight other pilots to finish first.

In 1913 Cody began designing a sea­plane that he flew successfully. On a later flight, however, the plane ran into mechanical problems. It plunged to the ground, and Cody and a passenger were killed. Britain mourned the loss of their hero, and the army offered to bury him in a military cemetery. Tens of thou­sands of people lined the roads as Cody’s coffin passed to his final resting place. Leila Marie Cody died in 1939.

When America went to war in 1941, the DC-3 became even more valuable as the C-47 military transport. During World War II, the airplanes were built at three plants: in Long Beach and Santa Monica, California, and in Oklahoma City, Oklahoma.

In its military role as the C-47 and other models, the DC-3 underwent internal changes. For troop carrying, the passenger cabin was refitted with utility seats that were set along the sides facing inward. The C-47 had twin radial engines, giving it a cruising speed of 207 miles per hour (333 kilometers per hour), and it had a range of 2,125 miles (3,420 kilometers). It could carry
up to 6,000 pounds (2,725 kilograms) of freight or twenty-eight fully equipped paratroopers. It was known as the Skytrain, the Skytrooper, and the “Gooney Bird.”

The C-47 proved to be an outstand­ingly successful troop carrier and was also widely used to drop paratroopers and tow gliders. C-47s, known in Britain as Dakotas, flew secret missions, often at night, over Nazi-occupied Europe. They dropped Allied agents, guns, and sup­plies by parachute to Resistance fighters. The aircraft also became a familiar sight to troops fighting on the Pacific and Southeast Asian battlegrounds. C-47s flew over the Himalayas between India and China and dropped ammunition,

food, and fuel to soldiers in jungle clear­ings in Burma or on small Pacific islands.

C-47s took part in the D-Day inva­sion of German-occupied northern France in June 1944. They also dropped Allied airborne troops during the Arnhem and Nijmegen assaults (in the Netherlands) in September 1944. Douglas supplied more than 10,000 C-47s to the Allies during the war, and a further 2,000 were built in Russia for use on the Eastern Front.

There were even DC-3s flying on the other side in World War II. The Japanese had bought twenty DC-3s in 1939 and had acquired a license to manufacture the plane. During the war, more than 400 Japanese DC-3s were used by the Imperial Japanese Navy. These planes, known as Showa L2Ds, were used main­ly as personnel transports.

An engine is a machine that changes heat into motion. Powered aircraft are propelled through the air by at least one engine. Several different types of engines are used in aircraft. An engine used for flight needs to be relatively lightweight, small, powerful, and reliable.

The First Aircraft Engines

The first engines used in the earliest attempts to build powered aircraft were steam engines. They were powerful engines, but they were also very heavy. They did sometimes manage to lift an aircraft off the ground for a few seconds, but it soon became clear that a different sort of engine was needed.

When the Wright brothers looked for an engine to power the world’s first air­plane, they were unable to find anything suitable, so they decided to build their own engine. It was a small gasoline-

О Four basic types of turbine engines are used today: the turbojet, the turboprop, the turbofan, and the turboshaft.

more powerful engines. These large, powerful piston engines produced a lot of vibration. One way of smoothing out the shaking was to fit a heavy metal wheel, called a flywheel, to the engine. The spinning wheel evened out the pul­ses of power produced by the cylinders.

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.