Category FLIGHT and M ОТІOIM

An autogiro is a type of aircraft that looks like a helicopter but works in a different way. Autogiros are rotorcraft, or rotary wing craft. Like a helicopter, an autogiro has a rotor (a set of long thin blades) on top. Unlike a helicopter, an autogiro’s rotor is not powered by an engine-it freewheels, or autorotates. An autogiro is moved forward by an engine-driven propeller, like an airplane.

Just before an autogiro takes off, the pilot starts the overhead rotor spinning. The simplest way to do this is for the
pilot to reach up, take hold of one of the rotor blades, and push it around. Some autogiros use their engine to start the rotor spinning, and then the engine is disconnected from the rotor to let it spin freely on its own.

As the autogiro moves forward, the pressure of air pushing up against the bottom of the blades makes the rotor spin faster. As the blades spin, they gen­erate lift. They quickly generate enough lift for the craft to take off. An autogiro can take off in a much shorter distance than a fixed-wing plane.

In the same way as a helicopter, an autogiro is steered by tilting the rotor.

When the whole rotor tilts, its down – wash (or the air blown downward by the rotor) is tilted to the front, back, or one side. This action pushes the autogiro in the opposite direction. A rudder at the back turns the craft’s nose to the left or right.

A rudder works by deflecting air to one side, so it needs a fast flow of air blowing across it to work. When an autogiro flies slowly, the air flows around it too slowly for the rudder to work well. A modern autogiro’s rudder, therefore, is placed behind its rear – mounted propeller. In this position, it gains a fast airflow from the propeller.

An autogiro has the same basic flight controls as a fixed-wing plane, but autogiros are much more maneuverable. A control stick steers the aircraft. Moving the stick to the front, back, or side moves the craft in that direction by tilting the rotor. Pedals operate the rud­der, and a throttle control adjusts the engine speed.

Spanish engineer Juan de la Cierva invented the autogiro in 1923. The first autogiros had short wings with ailerons for steering. In 1932 the wings were dis­carded, and a tilting rotor was used for steering instead. During the 1930s the development of helicopters overtook autogiros. Interest in commercial and military autogiros died away. A few autogiros were towed behind ships and submarines during World War II to act as spotter craft. They were used to look for enemy ships or submarine periscopes breaking the water’s surface.

AUTOGIRO TIME LINE

The Bell X-1 was basically a rocket engine with wings. The engine burned all its fuel in 2.5 minutes, and the X-1 certainly did not have enough fuel to take off under its own power-it would hitch a ride into the air beneath a B-29 Superfortress bomber. The bomber would climb to 25,000 feet (7,620 meters) before releasing the X-1.

The first flights of the X-1, which took place in Florida in early 1946, were unpowered. The X-1 then began to make powered flights from Muroc Army Air Field in California’s Mojave Desert. (The field was later renamed Edwards Air Force Base.) The rocket engine was tested for the first time by pilot Chalmers Goodlin, who made many successful test flights in the X-1. On the powered flights, the pilot ignited the rocket engine for a brief but very fast flight. When the engine cut out, the air­plane glided down, landing without engine power-a maneuver later used by the Space Shuttle.

At the time the fastest aircraft in the world was the British Gloster Meteor,

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CHARLES ELWOOD "CHUCK" YEAGER (BORN 1923)

Charles Elwood Yeager, always known as Chuck, was born in West Virginia. He flew as a fighter pilot in Europe during World War II, destroying thirteen enemy aircraft before being shot down over enemy territory in Europe. He managed to escape capture and make his way to England. After the war, Yeager became a flying instructor and test pilot, and he volunteered to fly the X-1. Between 1954 and 1962, he left test flying for other U. S. Air Force duties before returning to Edwards Air Force Base to head the Aerospace Research Pilot School. Yeager continued to fly fast airplanes. He had a nar­row escape in the 1960s when his NF-104 jet went into a spin and fell from a very high altitude. Yeager managed to eject and, although injured, parachuted down to land in the desert. In 1968 Yeager took command of a fighter wing. He retired in 1975.

which set a world speed record of 615 miles per hour (990 kilometers per hour) in September 1946. In August 1947 the Douglas Skystreak topped that with 650 miles per hour (1,046 kilome­ters per hour). No aircraft had yet flown supersonic in level flight.

black box is a recording machine carried by commercial and military aircraft and aboard the Space Shuttle. Designed to survive a crash, it is used to find out how an acci­dent occurred. Airplane crashes are very rare, but when a fatal accident does happen, it is important to find the cause. Knowing why one aircraft crashed may help to prevent other accidents.

After an accident, a team of investi­gators search through the wreckage, looking for clues. They also look for the piece of equipment referred to as the

THE FIRST BLACK BOX

The development of the black box flight recorder began in Australia in the 1950s. There had been a series of air crashes with no witnesses and no survivors. It was very difficult to find out what caused them. Dr. David Warren at the Aeronautical Research Laboratories of Australia wondered if a plane could be fitted with a recorder to give investigators infor­mation about a crash. His work resulted in the first flight data recorder in 1958. The first black boxes used magnetic tape to record and store information-today’s flight recorders use computer chips.

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black box. In fact, black boxes are not black-they are bright orange-and there are usually two of them.

The flight data recorder, one of the two black boxes, is the size of a large shoebox. To survive a crash, the box is made to withstand a force of 3,400 times the force of gravity for 6.5 milliseconds. (A millisecond is one-thousandth of a second.) It also withstands fire and being submerged in liquid.

The flight data recorder records hun­dreds of pieces of information about an aircraft. The data includes the aircraft’s speed, height, and direction. The device also records the positions of controls, the positions of the rudder and other control surfaces, and the engine speed.

The other black box is the cockpit voice recorder. It records sounds picked up by microphones in the cockpit. The pilots’ voices are recorded on one micro­phone. Another microphone in the cock­pit roof records the sounds of alarms, clicks of switches, and other background noises. At any moment, the box has retained the last thirty minutes to two hours of sound as a recording that can be retrieved if a plane crashes.

The information from both boxes is stored in computer chips. The chips are inside an extremely tough package called the crash survivable memory unit. The unit’s case is made of stainless steel or titanium. It is lined with fireproof insulation. To test the case’s toughness, the unit is fired out of a cannon and burned in a fire at 2000°F (1093°C) for an hour.

Some versions of the black box contain the flight data recorder and voice recorder in one unit. Whether they are combined

or separate, black boxes are usually installed in the plane’s tail, where they are most likely to survive. They may be thrown out of a plane by the impact of a crash, so they are designed to be easy to find. Apart from their bright color, they are fitted with a locator beacon that switches on automatically if the recorder lands in water. It emits an ultrasound pulse every second for a month. Divers or underwater craft can use the signal to locate the recorder. When a black box is found, the information in its memory can be downloaded and studied.

In the United States, black boxes are taken to the National Transportation Safety Board for expert analysis. Investigators include safety officials and representatives of the aircraft manufac­turer and operating airline. Together, these people try to piece together what happened in the last moments of a flight. Recorded conversations between
pilots can give clues, even if the pilots themselves did not know the cause of their problem. The flight data recorder offers minute detail of what the airplane was doing at any given second.

Cape Canaveral has a long association with aviation and spaceflight. During World War II (1939-1945), the U. S. Navy trained pilots there. After the war, the U. S. Army, U. S. Navy, and U. S. Air Force all used Cape Canaveral as a range for testing missiles.

In 1950 the U. S. Air Force took over the test range and set up the Cape Canaveral Air Force Station. It built a row of launch pads along the coast. The first rocket launch from Cape Canaveral took place at 9:28 a. m. on July 24, 1950. The rocket, named Bumper 8, was a modified World War II V-2 rocket.

The first launch control center was very basic. It was a small wooden shack about 450 feet (137 meters) from one of the launch pads. The launch center was buffered only

О Bumper 8 was the first mis­sile launched at Cape Canaveral. The launch, shown here, took place on July 24, 1950.

by a mound of dirt and sandbags, which would have offered little protection if a rocket had exploded on the pad. Later, a tank was used as a firing room to launch rockets.

There was so little housing at Cape Canaveral in the 1950s that most workers were obliged to live in tents. They had to deal with the local wildlife, which included mos­quitoes, alligators, and rattlesnakes.

Today, NASA has a fleet of satellites for communicating with Earth-orbiting satellites and manned spacecraft. This network of satellites is called the

Tracking and Data Relay Satellite System (TDRSS). When a ground station wants to send a signal to a spacecraft, it sends the signal up to the nearest TDRSS. The signal is then passed on from satel­lite to satellite around the world until it reaches a satellite in contact with the spacecraft. The TDRSS provides communication with many spacecraft, including the Space Shuttle, the International Space Station, and the Hubble Space Telescope.

TDRSS satellites orbit Earth 22,250 miles (35,800 kilometers) above the equator. This is a special orbit called geostationary orbit. A satellite in this orbit goes around the world once every 24 hours. As the Earth also spins once every 24 hours, this means that the satellite always stays above the same spot on Earth. As well as the TDRSS,

there are many other communications satel­lites using this orbit.

The radio signals sent to and from space­craft carry all sorts of information, including the voices of astronauts and mission con­trollers, video images from the Space Shuttle and International Space Station, command signals for controlling the movements of satellites, and science data from weather satellites and space tele­scopes. Engineering data also are sent automatically from rockets and spacecraft during missions so that mission controllers can monitor them. This form of com­munication is called telemetry.

Date of birth: July 24, 1897.

Place of birth: Atchison, Kansas.

Died: July 2, 1937.

Major contributions: First woman to fly alone across the Atlantic Ocean; first woman to fly alone across the United States; first person to fly from Hawaii to California.

Awards: Distinguished Flying Cross; French Legion d’Honneur; Harmon International Trophy; National Geographic Society Medal.

ne of the most celebrated of women aviators, Amelia Earhart is also at the center of a great mystery. On her last flight—a daring attempt to fly around the world—she disappeared, leaving no trace of herself or of her aircraft.

Early Life

In 1917, the year after she graduated from high school, Earhart joined the Canadian Red Cross to help soldiers fighting in World War I. Working at a military hospital, she got to know some airmen and became interested in flying. Earhart flew in an airplane for the first time in 1920, when she immediately became captivated by flying. She began taking flying lessons, although her parents objected. After earning her pilot’s license, Earhart scraped together enough money to buy an airplane.

Within weeks, Earhart set a record for women by reaching an altitude of

14,0 feet (4,270 meters). The record did not stand long, but the flight showed her daring. By the mid-1920s, Earhart’s parents were divorced, and she was living in Massachusetts with her mother. Earhart took a job as a social worker in Boston and on weekends she flew.

A fighter airplane is an aircraft designed for combat, usually with other military aircraft. Fighters are fast, agile, and equipped with detection systems and weapons to hunt enemy aircraft and shoot them down. A modern fighter plane flies up to 2.5 times the speed of sound (Mach 2.5). Because of the amount of weaponry it carries, a fighter is often as heavy as a World War II bomber.

When fuel burns, it combines with oxygen in the air. Without oxygen, fuel will not burn. Rockets have to function in space, where there is no air to supply oxygen, and so they carry their own supply of oxygen-or a chemical that contains oxygen, called the oxidizer – for burning the fuel. The fuel and the oxidizer also are called propellants.

Rockets can use kerosene fuel, just as aircraft do. The rocket fuel RP-1 is kerosene. The first stage of the giant Saturn V rocket that launched astro­nauts to the Moon during Project Apollo burned RP-1.

Hydrogen is another popular rocket fuel. The Space Shuttle’s main engines burn hydrogen and oxygen from an external tank. Hydrogen and oxygen are normally gases, but the tanks needed to carry enough of these gases to launch a heavy rocket into space would be gigantic. Hydrogen and oxygen, there­fore, are cooled and compressed until

TYPES OF FUEL

Every fuel has a flash point. The flash point is the lowest temperature at which a fuel can be set on fire by a spark or flame. A fuel with a low flash point catches fire more easily than a fuel with a high flash point. Avgas has a lower flash point than jet fuel.

they change to liquids, which take up much less space. Hydrogen has to be cooled to -423°F (-253°C). Oxygen has to be cooled to -298°F (-183°C). Super­cold propellants such as these are known as cryogenic propellants.

There are some chemicals that burst into flames as soon as they meet. They are useful as rocket propellants because they do not need a spark or flame to start them burning. Propellants of this type are called hypergolic propellants. Turning off the supply of hypergolic propellants stops a rocket from working. Turning them on makes the rocket fire again. Hypergolic propellants are used by small rockets that have to start and stop frequently, such as those that help the Space Shuttle maneuver in space.

O A solid rocket booster is maneuvered into place on a Delta II rocket that is being prepared for launch by NASA at Cape Canaveral Air Force Station in Florida.

The simplest rockets burn solid fuel, like giant fireworks. The fuel and oxidizer are mixed while liquid and then poured into the rocket, where they set hard. To fire a solid fuel rocket, a flame is sent down a hole through the middle of the rocket. Once a solid fuel rocket starts firing, it keeps going until all the propellant is used up. Small solid rockets are often strapped to the side of a bigger rocket to supply extra thrust for takeoff. The biggest solid fuel rockets ever built are the two solid rocket boost­ers (SRBs) that help to launch the Space Shuttle.

Glenn made history one more time. After he announced his retirement from politics, Glenn was asked by NASA if he would like to go into space one more time, on a Space Shuttle mission. The gesture was made partly to honor him and partly to study the effects of space­flight on older people—Glenn was in his seventies at the time. Glenn jumped at the chance to join the mission.

On October 29, 1998, Glenn left Earth once again. It was almost thirty-seven years since his first flight. Things had changed. This time, he was on board the Space Shuttle Discovery and had six crewmates instead of being the lone astronaut. The flight took more than nine days, whereas his previous flight

INSPIRATION FOR THE FUTURE

"The most important thing we can do is inspire young minds and to advance the kind of science, math, and technology education that will help youngsters take us to the next phase of space travel."

John Glenn, speaking as spokesperson for National Space Day, 2000

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had lasted just over 4 hours. For Glenn, going into space again was an enormous thrill.

After the flight, Glenn retired from public life. He and his wife Annie settled back in Ohio. Both served on the board of trustees at Muskingum College, where they had studied so many years before. Glenn opened a center at Ohio State University to encourage young people to start careers in public service.

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SEE ALSO:

• Astronaut • NASA • Pilot

• Spaceflight • Space Race

• Supersonic Flight

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Hang gliders can fly at speeds of up to 90 miles per hour (145 kilometers per hour), and they can encounter some rough weather conditions. They also can be tricky to fly. For these reasons, trainee pilots learn basic hang gliding skills on the ground and during brief “hops” into the air. Pilots in training will often

О A well-positioned platform sticking out from a hill also makes a good launching pad for a hang glider.

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PARAGLIDERS

A paraglider flies in a way similar to a hang glider. The difference is that a paraglider looks more like a parachute and has no rigid frame. The pilot sits in a seat harness

suspended beneath the canopy. The term paraglider was first used by aviation scien­tists in the 1960s. The sport paraglider was developed in the 1970s by French enthusi­asts, who were inspired by new, advanced parachute designs. French pilots made paragliding popular, and France still has the largest number of paragliders.

The paraglider is easy to pack and light enough to be carried, which is useful when a flight ends with the pilot landing miles away from the takeoff area. The paraglider trainee can learn most skills in the air.

The aircraft is easy to launch and fly in light winds, but it does not glide as well as a hang glider. For this reason, it usually cannot fly such long distances, although some paragliders have flown as far as 250 miles (400 kilometers).

fly tandem (two at a time) with an expe­rienced instructor.

The United States Hang Gliding Association provides licenses to hang glider pilots. This official body also issues certificates to instructors and enforces safety regulations that all pilots are expected to observe. Hang gliding is often thought to be a risky sport by peo­ple not involved in it. Although modern materials are both light and strong, a hang glider is a flimsy airplane that is
easily damaged. Accidents can happen, often as a result of unpredictable wind currents or weather changes. Hang glid­er pilots can carry a parachute in their harnesses for emergencies.

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SEE ALSO:

• Air and Atmosphere • Bird

• Glider • Global Positioning System

• Lilienthal, Otto • Wing

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