Category FLIGHT and M ОТІOIM

Dive Bombers and Heavy Bombers

In September 1940, the German Luftwaffe switched its attention to bombing British cities, beginning the Blitz. The British retaliated by bombing the German capital of Berlin. These offensives were the start of a strategic bombing war.

The Germans did not have a heavy bomber. Lacking a first-class bombsight to help them bomb from high altitudes, German designers had been told to give all bombers a dive-bombing capability so they could dive low over their targets for accuracy.

Dive bombers attacked in a steep dive; the pilot released his bomb above the target and zoomed away to avoid the explosion. Dive bombers were good at attacking ground targets, such as airfields, and enemy ships; the German Ju-87 Stuka was widely used for this.

Dive Bombers and Heavy Bombers

Dive Bombers and Heavy Bombers

FAMOUS FIGHTERS IN WORLD WAR II

Aircraft

Date

Country

Speed

Weapons

Hawker Hurricane I

1940

U. K.

310 mph (499 kph)

8 machine guns.

Mitsubishi A6M2 Zero

1941

Japan

332 mph (534 kph)

3 machine guns and 2 cannons.

Supermarine Spitfire V

1941

U. K.

369 mph (594 kph)

8 machine guns or 4 cannons.

Messerschmitt Bf 109F

1941

Germany

373 mph (600 kph)

2 machine guns and 2 cannons.

Focke Wulf Fw 190A-3

1941

Germany

418 mph (673 kph)

2 machine guns and 2 cannons.

Grumman F6F Hellcat

1943

U. S.

380 mph (611 kph)

6 machine guns.

North American P-51D Mustang

1943

U. S.

437 mph (703 kph)

6 machine guns.

Messerschmitt Me-262

1944

Germany

540 mph (869 kph)

4 cannons.

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This bomber’s weakness was its relative­ly slow speed, which made it vulnerable to fighters.

The British and the Americans were building four-engine heavy bombers, such as the Lancaster, Halifax, B-17, and B-24. From the time the United States joined the war (after the attack on Pearl Harbor in December 1941), these bombers played an important role in Allied offensive strategies.

Landing

When it reaches its destination, a probe may stay in orbit, radioing data and images back to Earth, or it may attempt to land a capsule on the surface. Landing on a planet many millions of miles away, under remote control, is always a challenge. The speeds of approach can be enormous. In 2003, the Galileo probe accelerated to 108,000 miles per hour (173,780 kilometers per hour) as it dived toward Jupiter.

Once on the target planet, a lander can use remote-controlled arms and scoops to collect samples of rock and soil. Its instruments analyze the samples and the gases in the atmosphere and measure temperature, pressure, and radi­ation levels. A few probes have released a small rover to explore the areas farther from the lander.

Some probes are sent to collect mate­rial and return it to Earth at the end of their mission. A reentry capsule drops down through Earth’s atmosphere, by parachute, for recovery on the ground or in the air using the “air snatch” tech­nique, by which an airplane scoops up the capsule before it hits the ground.

The B-2 Spirit Bomber

The B-2 Spirit bomber, which first flew in 1989 after years of secret develop­ment, is much larger and heavier than the F-117. It was built by Northrop – Grumman, a manufacturer that pio­neered flying wing designs in the 1940s.

In the 1980s, Northrop-Grumman tested a stealth plane, code-named Tacit Blue, which has been described as “an upside – down bathtub with wings.” The B-2 was more elegant, shaped like a flying arrowhead. Computer-aided design gave the B-2 similar radar-baffling character­istics to the F-117. The B-2 carries a crew of two and has a range of 6,000 miles (9,650 kilometers). It relies on its stealthy approach to outwit defenses because it is relatively slow, flying at around 500 miles per hour (800 kilome­ters per hour). The B-2’s uses are very specialized, and the plane is expensive to produce. Like the F-117, the B-2 has been built in small numbers—there are only about twenty B-2s in existence.

Other modern warplanes, such as the F-22 Raptor, the F-35 Lightning II (Joint Strike Fighter), and the European Typhoon have stealth characteristics, but their shapes are more conventional
than that of the F-117 and the B-2. A key element in their design is that no feature (such as an engine outlet or weapons bay) gives off more than the minimum radar reflection. Stealth fea­tures must be balanced against other elements of the design, such as the high speed that is essential for a fighter plane.

Wind Tunnel

A

wind tunnel is a piece of test equipment used by designers, scientists, and engineers to study the effects of air flowing around aircraft, rockets, missiles, automobiles, and even buildings. Every modern aircraft makes its first flight in a wind tunnel. Instead of the aircraft moving through the air, the aicraft is held still and the air moves around it.

Wind tunnel tests help designers and engineers to find problems with a design and to test solutions without risking a pilot in test flights and without the expense of building a full-size aircraft.

Most wind tunnels are not big enough to hold an entire aircraft. A small and very accurately built model of an air­craft may be used, or just part of an aircraft. Wind tunnels vary greatly in size and airspeed, but they have the same basic parts.

Space Shuttle

T

he Space Shuttle was the world’s first reusable spacecraft and the first spacecraft with wings. The Space Shuttle can carry seven astronauts into space, stay in orbit for about two weeks, and then fly back to Earth to land on an airstrip.

The Shuttle Concept

Until the first Space Shuttle flew in 1981, all spacecraft (manned craft, satel­lites, and space probes) were launched by multistage rockets. Such rockets and the spacecraft they carried could be used just once. Only the spacecraft itself reached space; the discarded rocket stages fell into the sea or burned up in the atmosphere. The Space Shuttle was planned as a more economical vehicle
that could make regular trips into space. It has no rival. The Soviet Buran shuttle spacecraft, similar in appearance, made only one flight, without a crew, in 1988; it was thereafter canceled.

In 1969, a Space Task Group set up by President Richard Nixon’s adminis­tration suggested several new space projects. One was a reusable spacecraft, capable of flying one hundred or more missions. The result was the Space Shuttle, known to NASA as the Space Transportation System (STS). The main contractor was North American Aviation (later part of Rockwell International, now part of Boeing). Other contractors responsible for supplying the engines

О A view inside the Space Shuttle shows the giant engines, the cargo bay, and the flight deck and mid-deck where the astronauts live.

Space Shuttle

Rudder and speed brake

Main engines (3)

Maneuvering engines (2)

 

Forward

control

thrusters

 

Hydrazine and nitrogen tetroxide tanks

 

Space radiators (inside doors)

 

Manipulator arm

 

Cargo bay

 

Flight

deck

 

Space Shuttle

Space Shuttle

Подпись: Unite'Подпись: Nose Mid-deck gear Air

control

thrusters

Electrical system fuel cells

Body flap Elevon

 

Main gear

 

Space Shuttle

and fuel tanks, were Morton Thiokol, Martin Marietta, and Rocketdyne.

The first Shuttle to fly was Enterprise, which was used for prelimi­nary flight and landing tests from 1977. These tests included flights on top of a modified Boeing 747 airplane. Enterprise never actually went into space. Five Space Shuttles have flown in orbit. The first operational Space Shuttle, delivered to NASA in March 1979, was Columbia, which made its first space flight on April 12, 1981, and remained in service until it was destroyed in a tragic accident in 2003. Challenger, which arrived at Kennedy Space Center in July 1982, was the first Space Shuttle to be lost in an accident, in January 1986. The three Space Shuttles currently operational are Discovery, delivered in November 1983; Atlantis, delivered in April 1985; and Endeavour, which was built to replace Challenger and arrived at Kennedy Space Center in May 1991.

. Tail

A

n aircraft’s tail helps to keep it stable in the air. The tail’s con­trol surfaces make the aircraft climb, dive, and turn to the left or right.

An airplane’s tail acts like an arrow’s feathers or a firework rocket’s long stick. The tail keeps the plane pointing in the right direction, nose first. Without a tail in place, most airplanes would crash to the ground. The Northrop B-2 Spirit stealth bomber, for example, has no tail and is therefore a very unstable aircraft. It only can be flown with the help of a powerful flight computer.

Stabilizers

A typical airplane tail has a vertical sta­bilizer, or fin, that stands up on top of the fuselage, and a horizontal stabilizer, or tailplane, which sticks out from either side of the tail fin. The fin has a moving part at the back called the rudder. When the rudder is turned to the left, the air
flowing around it pushes the plane’s tail to the right, and the aircraft’s nose turns to the left. When the rudder turns to the right, the aircraft’s nose turns to the right.

The tailplane has moving parts at the back called elevators. The elevators con­trol the aircraft’s pitch. When the eleva­tors tilt up, air flowing around them pushes the aircraft’s tail down and brings the nose up. When the elevators tilt down, the aircraft’s nose tips down as well.

World War I

W

orld War I began in Europe in 1914, and the United States entered the war in 1917. Remembered for the terrible slaughter of trench warfare on the Western Front, the “Great War,” as World War I became known, was the first war in which air­planes played an important part.

World War I

LEARN-EARN

О A World War I poster encourages volunteers to enlist in the Air Service, part of the U. S. Army. At the time, there was no separate U. S. Air Force. The poster reflects the aircraft of the period, including airships.

The Role of Aircraft

Until 1914, military strategists regarded command of the sea as the key factor in international warfare. Britain, Germany, and the United States had the biggest navies. When World War I began, air­planes were still a novelty. The fastest airplane had a top speed of only 100 miles per hour (160 kilometers per hour) and a range of about 100 miles (160 kilometers) before needing to refuel.

In the nineteenth century, balloons and airships had been used in wars, mostly for observation and for evacua­tion of civilians. The military had yet to find uses for the airplane. In 1912, Britain had set up a Royal Flying Corps, but it had very few aircraft. Germany had the largest air force, with more than 200 airplanes plus Zeppelin airships. The U. S. Army had purchased its first air­planes in 1913. No nation had assembled a large air force.

In the four years of World War I (1914-1918), the airplane became a much more formidable weapon. Fighter planes battled in aerial combats called dogfights. For the first time, cities were bombed from the air by airships and air­planes. The warring nations formed air forces or aviation divisions within their armies and navies. War would never be the same again.

September 11, 2001

The worst skyjacking in history hap­pened in the United States in 2001. On the morning of September 11, nineteen terrorists hijacked four U. S. airliners: American Airlines Flights 11 and 77 and United Airlines Flights 93 and 175. Flights 11 and 175 had taken off from Boston, Massachusetts; Flight 77 left from Dulles Airport in Washington, D. C.; and Flight 93 departed from Newark, New Jersey. The first three airplanes were on early-morning flights to Los Angeles, California; the fourth was heading for San Francisco, California.

Two of the hijacked planes (Flight 11 and Flight 175) were deliberately flown into the twin towers of the World Trade Center in New York City. Flight 11 hit the North Tower just before 8:45 a. m. Flight 175 hit the South Tower at 9:03 a. m. Both 110-story structures became fiery infernos, pouring black smoke into a blue sky, before collapsing to the ground. At 9:40 a. m., Flight 77 was flown into the side of the Pentagon in Washington, D. C.

On Flight 93, the hijackers-who had smuggled knives onboard-had locked themselves in the cockpit and headed the plane toward Washington, D. C. Flight 93’s passengers learned from cell

О Terrorists flew an airplane into the Pentagon building in Washington, D. C., as part of their skyjacking operation on September 11, 2001.

Подпись: О In New York City, two blue beams of light shine into the night sky in the place where the twin towers of the World Trade Center once stood. phone calls to friends and relatives what had happened to the other three planes. They decided to attack the hijackers. The plane went out of control and crashed near Shanksville, Pennsylvania.

Every person onboard the four hijacked airplanes, including the hijack­ers, was killed. Furthermore, many more people were killed on the ground in New York City and Washington, D. C. The total death count was 2,752 at the World Trade Center, 189 at the Pentagon, and 44 in Pennsylvania.

Into Orbit

On October 4, 1957, the rocket carrying “Elementary Satellite 1,” or Sputnik 1, took off from the desert near Tyura-Tam, in what is now the Kazakh Republic. All went well, and the first radio signals from space told the waiting Soviet sci­entists that Sputnik 1 was in orbit. They announced their success to the world, and almost every newspaper, radio, and television network carried the story. Sputnik 1 was headline news. Astronomers trained radio telescopes on the tiny satellite. Amateur radio enthu­siasts in many countries picked up the satellite’s “beep beep” radio signals as it passed overhead.

Into Orbit

Sputnik 1 had a brief working life, but its historic flight proved that a human-made craft could survive launch and fly in orbit. The scientific data gath­ered from the flight was limited, but Sputnik 1 did help to identify the density of the layers in the upper atmos­phere and provided useful information on how radio signals from space were received on Earth.

Scientists had feared that space dust or meteoroid impact might damage the spacecraft. Even a minute hole in the satellite would have caused a detectable drop in pressure and temperature. However, Sputnik 1 continued to orbit Earth undamaged. The spacecraft’s radio batteries ran out before the end of October, after which no more signals were received. The satellite stayed in orbit until January 1958, when it burned up as it reentered Earth’s atmosphere, having traveled about 37 million miles (60 million kilometers).

VTOL, V/STOL, and STOVL

T

he capability of a fixed-wing air­craft to take off and land vertical­ly is known as vertical takeoff and landing, or VTOL. Some aircraft have the ability to take off and land on a very short runway-these are V/STOL aircraft. V/STOL stands for vertical or short takeoff and landing. Still others are STOVL aircraft-they are capable of a short takeoff and vertical landing. The terms are used to describe a small group of fixed-wing aircraft. They do not include helicopters, airships, or rockets, all of which also have the ability of vertical takeoff.

Propeller Planes

Fixed-wing aircraft normally need a long takeoff run to get airborne. They cannot take off until their wings are moving through the air fast enough to create enough lift to overcome the plane’s weight. If a fixed-wing aircraft is to take off vertically, it needs to direct its engine power downward with enough force to overcome its weight.

Propeller planes can do this by tilting their engines and propellers so they work like helicopter rotors. The V-22 Osprey, a V/STOL aircraft, swivels its propeller engines up for takeoff and landing and angles them forward for regular flight. Its propellers work like helicopter rotors for vertical flight and like propellers for forward flight, so they are called prop-rotors. They are made bigger and stronger than normal pro­pellers because they must support the entire weight of the aircraft for takeoff and landing. Aircraft such as the V-22 Osprey are called tilt-rotors.