Category FLIGHT and M ОТІOIM

Helicopters also change their attitude by pitch, roll, and yaw motions, but they do it differently from fixed-wing airplanes. Unlike airplanes, helicopters do not have wings, ailerons, elevators, or a rudder. Instead, they use their main rotor, the spinning blades on top, for pitch and roll move­ments. Tilting the whole rotor forward or back­ward changes the pitch of a helicopter. Tilting the rotor to one side or the other makes the air-

POINTING AT THE HORIZON

During daylight, pilots often keep an aircraft’s attitude under control by simply looking out of the window.

To keep an airplane flying straight and level, the pilot keeps its nose pointing at the horizon and the wings level with the horizon. This is called visual flight. If the horizon is not visible because of darkness or clouds, an instrument in the cockpit called the artificial horizon is used instead. It shows an outline of the plane’s wings in front of a ball with the horizon marked on it. Whatever way the plane moves, the ball rotates to keep its artificial horizon in line with the real horizon. A glance at this instrument shows whether or not the plane is level.

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craft roll. Speeding up or slowing down the small rotor in the helicopter’s tail makes the aircraft yaw to the left or right.

The Space Shuttle looks like a delta­wing airplane. It uses elevons in its wings to control pitch and roll. A rudder in its tailfin controls yaw. It also has a hinged panel called the body flap under its tail. No other aircraft or spacecraft has this control surface, which is used to trim the Space Shuttle’s pitch. In space, the Space Shuttle is unable to change its attitude in the same way as a plane
because elevons and rudders do not work in space. Instead, it fires small rocket thrusters in its nose and tail.

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SEE ALSO:

• Aileron and Rudder • Control System • Lift and Drag • Tail

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The force produced by a rocket engine is called thrust. The upward force of thrust must be greater than the downward force of gravity if a rocket is to take off. One measure of an engine’s power and efficiency is its thrust-to-weight ratio. Rockets have the highest thrust-to – weight ratios of all engines.

Most rockets work by means of chem­ical reactions, combining two chemicals, or propellants: a fuel and an oxidizer. The oxidizer, consisting of oxygen or a

О A rocket must produce huge upward thrust to get into space. It does this by producing a high – pressure jet of hot gases.

chemical containing oxygen, is needed to burn the fuel. Burning produces hot gases that expand rapidly and rush out of the engine nozzle at high speed. According to Newton’s third law of motion, the gas jet pushes against the rocket, and the rocket pushes back against the gas jet with the same force. The result is that the rocket is thrust in one direction as the gas flies in the opposite direction.

Other types of rockets produce thrust from a high-pressure jet of water, air, steam, or another gas. Ion engines pro­duce thrust by accelerating electrically charged gas particles.

One way to make a rocket accelerate faster, go farther, or carry a heavier pay­load is to make it lighter. For this reason, large rockets usually are built as a series of rockets standing on top of each other. The individual rockets are called stages. When each stage uses up its fuel, it falls away and the next stage fires. This enables the rocket to get rid of unneces­sary weight that would slow it down.

Date of birth: May 2, 1889.

Place of birth: Kiev, Ukraine.

Died: October 26, 1972.

Major contributions: Built the first successful single-rotor helicopter; built the first multi-engine airplane; built large aircraft used in early transoceanic passenger flights.

Award and Honors: Cross of St. Vladimir; Sylvanus Albert Reed Award; Presidential Certificate of Merit; Daniel Guggenheim Medal; Elmer A. Sperry Award; National Defense Award; National Medal of Science; Wright Brothers Memorial Trophy; Hawkes Memorial Trophy; Potts Medal; elected to National Aviation Hall of Fame; many honorary degrees.

gor Sikorsky was born in Kiev, Ukraine. He gained from his mother an interest in the work of artist and inventor Leonardo da Vinci, in particu­lar his drawings of flying machines. At age twelve, Sikorsky made a model helicopter powered by rubber bands and made it rise into the air.

Two years later, in 1903, Sikorsky became a student at Russia’s Naval Academy in the city of St. Petersburg. He became more interested in engineer­ing and left to pursue his studies. After two years of schooling in Kiev, Sikorsky dropped out to focus on experimental work of his own. That year, 1908, he also developed a passion for flight. After seeing photographs of the Wright broth­ers’ successful flights, Sikorsky later

recalled, “I decided to change my life’s work. I would study aviation.”

erobatics is a form of aviation in which pilots perform by flying in patterns or drawing figures in the sky. Aerobatic stunts include loops, corkscrews, stalls, spins, and rolls. The name aerobatics came from the word acrobatics. The pilot makes the plane tumble around the sky like an acrobat. Several aircraft flying together in for­mation make patterns.

How Aerobatics Began

One of the earliest aerobatic maneuvers was looping the loop (flying a complete vertical circle), first performed by a Russian pilot in August 1913. One month later, the French pilot Adolphe

Pegoud startled onlookers by flying his Bleriot plane upside down. Pegoud had trained for this stunt by having the air­plane fixed upside down in a hangar. He strapped himself into the pilot’s seat, head down, for twenty minutes.

In the 1920s, pilots known as barn­stormers flew stunts that would not be permitted today. Their tricks included skimming under bridges and racing railroad trains. There were also wing­walking displays, with people standing on top of aircraft wings. This stunt is still performed at air shows.

In the 1930s, air force pilots used aerobatic displays to demonstrate tactics used in air combat. They flew in groups that formed patterns, or in formation. Close formation flying included stunts with planes tied together.

The first world championships in aerobatics were held in 1960. In modern-day competitions, there are events for teams and individual pilots. Aerobatic contests are flown at heights from 328 to 3,280 feet (100 to 1,000 meters).

By the end of the twentieth century, most new aircraft were too complex and expensive for small companies to build.

Only very large corporations could afford the research needed to design and build rockets and spacecraft. Many famous industry names were merged into larger corporations. McDonnell joined with Douglas in 1967 to form McDonnell Douglas, for example, and that company is now part of Boeing.

In the twenty-first century, the aero­space industry is dominated by these large companies. Many are huge: 63 percent of jobs in aerospace manufac­turing are in businesses that employ more than 1,000 people. There are also many small subcontractors, however, that have fewer than 100 employees.

Designing and making an airplane or spacecraft now involves thousands

of people, working in different places, who have specialized knowledge and skills. Aerospace workers, such as engi­neers, computer scientists, and systems analysts, are well educated and highly trained. For many technical jobs, such as assembly workers, electricians, machin­ists, and toolmakers, workers need a good high school education, followed by technical training and apprenticeship. Production workers in the aerospace industry generally earn higher-than – average wages, but they also work a longer-than-average week.

The world aerospace industry is dom­inated by the United States and Europe, although there are important aerospace manufacturers in other nations, includ­ing Russia, China, Brazil, India, and Japan. Many of the world’s commercial airplanes are made in the United States. The biggest airplane factory in the world is the Boeing plant located in Everett, Washington-in fact, it is the world’s single largest building.

U. S. aerospace manufacturers ship goods worth many billions of dollars every year. Many airplanes, civil and military, are exported to other countries. Japan, France, the United Kingdom, Canada, and China are major markets for the aerospace industry and especially for U. S. products. The industry in the United States employs hundreds of

О The Cleveland National Air Show combines displays of new and historic aircraft with aerobatic performances. The show attracts thousands of visitors every year.

AEROSPACE INDUSTRY LEADERS

thousands of people. The states with the most aerospace jobs are Washington and California, and there are also large employers in Arizona, Connecticut, Kansas, and Texas.

Airplanes fly along set routes, called air­ways, in the same way that cars travel

Farsighted military experts, including Colonel Billy Mitchell of the U. S. Army, predicted that the bomber plane would hold the key to victory in any future war. This forecast proved to be deadly accurate. At the beginning of World War II (1939-1945), the German Luftwaffe (air force) blasted its way across Europe in blitzkriegs (meaning “lightning wars”) that overran Poland, Holland, Belgium, and France.

The major air battle of World War II was the Battle of Britain (1940), in which British Spitfires and Hurricanes went into combat against Germany’s Messerschmitts. Superiority in the air helped the Allies win invasion battles in North Africa, Sicily, and France. Allied bombers, meanwhile, pounded German factories and cities.

In 1941, Japan used carrier-based airplanes to bomb the U. S. naval base at Pearl Harbor, bringing the United States into World War II. Later sea battles in the Pacific were won by U. S. naval air­planes rather than by the navy’s ships. Key U. S. warplanes included fighters such as the P-51 and bombers such as the B-24, of which 18,000 were built (more than any other World War II bomber). The surrender of Japan in 1945 came after U. S. bombers dropped two atomic bombs that devastated the cities of Hiroshima and Nagasaki.

World War II also saw the first use of important new aviation technology, including radar, long-range rockets, cruise missiles, and jet planes. The first

TEC

AIRCRAFT DESIGNATION

Aircraft types are designated by a system of letters and numbers. The first letter indicates the aircraft’s type or role. F indicates a fighter plane, while H stands for helicopter.

The number after the first letter indi­cates an aircraft’s place in develop­ment history. After the F-7 Tigercat, for example, came the F-8 Bearcat and then the F-9 Panther. A second letter indicates a later, usually improved model. The F-14 Tomcat began life as the F-14A (1972); later models were the F-14B and F-14D. Some of the military aircraft desig­nations are:

A attack

B bomber

C transportation

E electronic warfare

F fighter

H helicopter

O observation

T trainer

U utility

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jet in combat was Germany’s Me-262. With a speed of almost 550 miles per hour (885 kilometers per hour), it was much faster than a propeller-driven fighter. The first American jet fighter to enter service was the XP-80 Shooting Star, first flown in January 1944.

Airports may be ranked in terms of number of flights or number of passen­gers. Most U. S. airports handle more domestic flights than international flights. The busiest airport in the world is Hartsfield-Jackson in Atlanta, Georgia, which handles more than 84 million passengers each year. Atlanta is closely followed by O’Hare International in Chicago, with 76 million passengers. The world’s busiest airport for interna­tional travel is Heathrow in London, England, with about 60 million interna­tional arrivals and departures each year. The airport that handles the most inter­national passengers in the United States

THE WORLD’S BUSIEST AIRPORTS

is John F. Kennedy International in New York City. New York has two interna­tional airports-Kennedy, or JFK, and Newark. Tokyo, Japan, also has two international airports operating from its capital city-Haneda and Narita. Heathrow, Gatwick and Stansted airports offer passengers international flights from London, England.

The busiest cargo airport in the United States is Memphis International in Tennessee. It handles over 2.87 mil­lion tons (2.6 million metric tons) of freight a year. Most airfreight going through Memphis is transported by FedEx, the international courier service.

Even before President Kennedy made his challenge, NASA had launched Project Mercury. The project took the first American, Alan Shepard, into space on May 5, 1961, but he did not orbit Earth. After a second suborbital flight in 1961 by U. S. astronaut Virgil “Gus” Grissom, the first orbital flight by a U. S. astronaut was made by John Glenn on February 20, 1962. Three more Mercury flights followed, testing various aspects of spaceflight and increased flight time.

NASA’s next program was Project Gemini, designed to address some of the challenges faced in taking people to the Moon. NASA had chosen an option that would involve a rendezvous, or steering two spacecraft near each other. It would also require docking, which meant join­ing the two spacecraft together. None of this had been done before, and the steer­ing and navigation techniques needed to perform the tasks had never been tested.

In 1965 and 1966, ten manned Gemini missions tested several new space techniques. Gemini 3 had the first on-board computer used by astronauts. Ed White became the first American to “walk” in space when he left the safety of Gemini 4 and floated in space attached by two cords. Gemini 6 and Gemini 7 achieved the first rendezvous when they met up in December 1965. The astronauts on Gemini 7 stayed in space for two weeks, showing that it was possible for people to survive long enough to travel to the Moon and back. On March 16, 1966, Gemini 8 performed the first docking of two space vehicles in orbit. The docking was performed by Neil Armstrong, who would be the com­mander of Apollo 11. All the Gemini flights contributed vital knowledge and experience to Project Apollo.

Other industries are beginning to use avionics technology that was developed for aircraft and spacecraft. Some ships are now fitted with transponders that send out a radio signal to identify the ship, just like airliner transponders. The control center of a modern passen­ger liner or cargo ship is known as the bridge. The bridge is fitted with flat panel screens showing information col­lected by sensors all over the ship.

Many vehicles now have electronic systems to control their engines, just like a plane’s engine management system. Increasing numbers of vehicles are using the same satellite navigation system that commercial and military aircraft use.

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SEE ALSO:

• Cockpit • Communication • Control

System • Fighter Plane • Materials

and Structures • Navigation • Radar

• Space Shuttle