A big jumbo jet can weigh as much as 70 elephants. So how can it float up in the sky, high above the clouds? It's not magic. It's air!
This is Lin, and this is Poppy, Lin's little yellow airplane. Let's find out how Poppy flies!
👆 Tap the glowing circles. Tap 📖 Read to me to hear the story. Press Next ▶ to keep reading, or jump straight to the game.
You can't see air, but it's real stuff! Air is made of tiny, tiny bits that zoom around and bump into everything.
When air moves, it can push. Feel the wind push on your face? That's air! It pushes Lin's kite way up high. 👆 Tap the kite!
⚖️ Air even has weight. All the air in a classroom weighs about as much as three grown-ups!
Four pushes and pulls work on every airplane, like a big tug of war. Weight pulls Poppy down. Lift from the wings pushes up. Thrust from the propeller pushes forward. Drag, the air rubbing past, holds Poppy back.
When lift beats weight, Poppy goes up! 👆 Tap each arrow.
🧲 Scientists call these the four forces of flight. Every plane, from a paper plane to a jumbo jet, has all four.Here is a wing, cut in half so we can see its shape. It is rounded on top and a little tilted. As it slices through the air, it bends the air down.
Remember action and reaction? The wing pushes air down, so the air pushes the wing up! That push is called lift. 👆 Slide to tilt the wing. Too much tilt? The air can't follow the wing anymore. That's a stall!
🤔 True or false? "The air over the top has to meet the air under the bottom at the back." False! NASA says the air over the top actually gets to the back first. Air speeds up over the top, so it pushes down on the wing less than the air underneath pushes up.
Wings only make lift when air rushes past them fast. That's why airplanes race down a long runway before they fly.
Go twice as fast, and the wings make four times the lift! A big jet lifts off at about 250 to 300 km/h, more than twice as fast as cars on a highway. 👆 Press Full power!
🐦 Birds take off the same way. Big birds like swans run along the water, flapping hard, until there's enough air rushing over their wings.
Where does the speed come from? Poppy's propeller is like a spinning pair of little wings. It grabs air and throws it back. Action and reaction: the air pushes Poppy forward! That's thrust.
Big jets have jet engines instead. They suck in air, squeeze it, heat it up and blast it out the back, super fast.
🏊 Drag is the air pushing back. Planes have smooth, pointy, rounded shapes so the air slips past. Swimmers make themselves long and smooth for the same reason!
How does a pilot steer? With the stick! It moves little flaps on the wings and tail that bend the air.
Pull back: the tail's flap tips up, the tail goes down and the nose goes up. Tilt the stick: one wing gets more lift, the other less, so the plane leans and turns, like a bike leaning into a curve. 👆 Try it!
🦶 Pilots also have pedals for their feet. They move the rudder, the flap on the tall tail fin, to swing the nose left or right.
Landing is the trickiest part! Pilots go through a checklist: Gear down, so the wheels are ready. Flaps down, so the wing gets bigger and can fly slowly. Then slow down and glide toward the runway.
Just before the wheels touch, the pilot gently lifts the nose for a soft touchdown. 👆 Do the checklist, then land!
✅ Real pilots use checklists every single flight, even pilots who have flown for 30 years. That's how they never forget a step.
Big jets fly about 10 to 12 kilometers high. That's higher than Mount Everest, the tallest mountain on Earth! Up there the air is thin, so there is less drag and jets can zoom at about 900 km/h.
Stack up Taipei 101, one of the tallest buildings in Taiwan. You'd need about 20 of them to reach a jet! 👆 Press the button.
🛩️ The very first airplane flight, by the Wright brothers in 1903, lasted just 12 seconds and went 36 meters. That's shorter than the wings of a jumbo jet!Wings bend the air down, so the air pushes the wings up. The faster the air, the more lift. The propeller or jet engine pushes air back for thrust.
🧠 Quick Quiz!