Planes designed for use on warships called aircraft Dangerous Ice! The Magic of Wings carriers often have folding If water freezes on a wing, it In freezing weather, airliners are wings so that they take up can interfere with the wing’s often sprayed with an antifreeze ings do something amazing. less space on the ship. smooth airfoil shape. An ice- chemical that keeps ice from A Clever Shape covered wing produces less lift, forming or melts ice on the When they move through air, which can be dangerous. A wing’s shape deflects air wings and tail. downward. The air pushes they create the upward force of back, creating an upward force lift that enables heavier-than- of lift. Air pressure above the wing falls, and pressure below air planes to fly. A wing’s secret it rises, creating more lift. is its special shape, called an Tilting a wing magnifies this effect and creates even more Wairfoil. It works by changing the direction of lift. the air flowing around it. A wing has to keep moving to create lift. As soon as it stops, there is no lift. And if a wing slows down too much Fascinating Fact or tilts up at the front too much, it can suddenly Slats and Flaps Giant airliners need huge wings to lift their massive weight lose all lift. This sudden loss of lift is called At takeoff and landing, a plane flies slowly and its into the air. The Airbus A380’s stalling. Pilots are trained to avoid it. wings create less lift. To make wings cover an area big enough more lift for flying safely at to hold 70 cars. lower speeds, planes make In level flight, a large their wings bigger. Panels airliner’s wings create called slats slide out in front several hundred tons of of each wing, and panels lift, exactly balancing the called flaps slide out at aircraft’s weight. the back. Slats

Flaps

8 9 The fuel tanks of a giant Jet Power Can You A380 airliner can hold more 1,300 miles per hour (2,100 Most of the biggest and fastest than 80,000 gallons (300,000 The Power to Fly kph). Because of this, the jet Believe It? planes are powered by jet liters) of fuel weighing 279 blast behind a plane can pose a engines. A large jet engine Fuel burning inside a tons (254,000 kilograms). hazard to nearby vehicles. he power to fly is provided by an accelerates the air flowing jet engine can reach a through it to a speed of about temperature of 3,500 degrees aircraft’s engine. The engine works Fahrenheit (2,000 degrees by burning fuel. An engine that burns Celsius). Parts of the engine fuel inside it is called an internal begin to melt at 2,372°F (1,300°C), so jet engines need combustion engine. Burning is a sophisticated cooling systems chemical reaction between the fuel and to stop them Toxygen in the air. The chemical reaction gives from melting! out energy in the form of heat. Heating the gases That’s a inside the engine makes them expand very powerful Piston Engines quickly. The force of the expanding gas can then engine! The smallest planes are turn a propeller or form the powerful jet of gas powered by engines that work produced by a jet engine. like car engines. Fuel burns in a series of explosions inside the engine, making pistons move back and forth, turning Air If an airliner’s engines a shaft that spins a propeller. enters Chemical reaction stop working, it doesn’t through The spinning propeller pushes between air and fuel Jet of gas used to fall out of the sky. A large Fan Jets fan blades. The fan, at the front of air backward to make the propel aircraft airliner can glide without Most large airliners use a type the engine, produces most of plane move forward. engine power for about of jet engine called a turbofan. the engine’s power and thrust. 100 miles (160 km). The jet engine spins a big fan like a propeller with dozens of

Turbine Nozzle It’s huge! Compressors Combustor

10 11 Delta Wing Sonic Boom Even Faster Faster Than Sound When a plane flies faster than the aircraft, and if it sweeps An experimental hypersonic A triangular wing called a sound, it squishes the air in over people on the ground, aircraft called the X-51A delta wing is a very good front of it. This squished air they hear it as a loud bang reached speeds over five shape for supersonic flight. s faster and faster aircraft were built, is called a shock wave. The called a sonic boom. times the speed of sound Planes with delta wings look their top speed began to get close to the shock wave spreads out from during a test flight in 2013. a little like paper darts. But you won’t be flying in a speed of sound. But pilots found that hypersonic airliner any time their planes suffered a sudden increase soon. It could take more than in drag as they neared the speed 20 years to build one. of sound. The planes often became difficultA to control. The speed of sound seemed to be a wall that couldn’t be crossed. It became known as the sound barrier. But eventually designers learned how to make planes that could fly faster than sound. They are supersonic. Speeds faster than five times the speed of sound are hypersonic. The first supersonic flight was made on October Fascinating 14, 1947, by US Air Force We’re really captain Chuck Yeager Fact moving! The speed of sound in air flying a Bell X-1 rocket depends on how warm or plane. cold the air is. Whatever the actual speed is, the speed of sound is also called mach 1.

The fastest ever aircraft with from space at 25 times the wings flown by a pilot was speed of sound, or about the Space Shuttle Orbiter. It 17,500 miles per hour re-entered Earth’s atmosphere (28,000 kph). 12 13