The quick answer
A plane’s wings are shaped and tilted to push air downwards. The air pushes back and lifts the wings up. The engines keep the plane moving fast, because wings only make lift when air rushes over them.
RankiTanki, a big plane is heavier than a whole herd of elephants. How on Earth does it stay up in the sky?
TankiDid you know the answer is all around us? It is the air. Let me show you how it works.
Four forces
Four act on a plane all the time. A force is a push or a pull. Two of these forces help the plane fly, and two try to stop it.
- Lift pushes the plane up.
- Weight pulls the plane down. This is , the pull of the Earth.
- pushes the plane forwards.
- is the air rubbing against the plane and slowing it down.
To take off, lift must be bigger than weight. Thrust must be bigger than drag. When the forces balance, the plane flies along at the same height and speed.
Wings push air down
Look at a plane’s wing from the side. It is curved on top. It is also tilted up a little at the front. When the plane rushes forwards, the wing slices through the air.
The shape and tilt of the wing send the air flowing downwards behind it. When the wing pushes air down, the air pushes the wing up. That upward push is lift.
Something else happens too. The air over the curved top speeds up, and its drops. Pressure is how hard the air presses on things. The air under the wing presses harder, so it helps push the wing up.
RankiSo a plane stays up by shoving the air around? That is quite rude of it.
TankiHa, maybe. Birds do exactly the same thing every time they flap their wings.
Engines and speed
Wings only make lift when air rushes over them. That is why planes need speed. The engines give the plane thrust. Jet engines suck in air, squeeze it and burn fuel. Then they blast hot gas out of the back.
Smaller planes often use instead. Propellers are spinning blades that pull the plane forwards through the air. Before take-off, a big passenger plane races down the runway much faster than a car on a motorway.
Pilots steer with flaps on the wings and the tail. Moving these flaps changes how the air flows. Then the plane can turn, climb or go down.
The very first flight
People dreamed of flying for thousands of years. Two American brothers, Orville and Wilbur Wright, finally made it happen. On 17 December 1903, near Kitty Hawk in the USA, their plane flew with an engine for the first time.
Orville was the pilot. The flight lasted only about 12 seconds and covered about 37 metres. That is shorter than the wings of a big passenger plane today, from tip to tip. The brothers flew three more times that day. The longest flight lasted 59 seconds.
Try it
Test your paper plane wings
You need
What to do
- Fold a simple paper plane. Throw it gently and count how far it flies in big steps.
- Fold the back edges of both wings up a little. Throw it again.
- Now fold the back edges down a little and try once more.
- Write down which plane flew the furthest. Can you work out why?
- Always throw your plane away from people’s faces.
RankiSo the wings push air down, the air pushes back, and the engines keep everything moving. Clever.
TankiNext time a plane flies over, wave at its wings. They are doing all the hard work!
Big words
- forces
- Pushes or pulls that make things move, stop or change direction.
- gravity
- The pull of the Earth that makes things fall down.
- thrust
- The push that moves a plane forwards, made by its engines.
- drag
- The way air rubs against a moving thing and slows it down.
- pressure
- How hard air or water presses on something.
- propellers
- Spinning blades that pull a plane through the air.
Quick quiz
1. Which force pushes a plane up?
Lift is the upward push made when the wings send air downwards.
2. What do the wings push downwards to make lift?
Wings send air downwards, and the air pushes the wings up.
3. Who made the first powered plane flight in 1903?
Orville and Wilbur Wright flew their plane with an engine on 17 December 1903.
For parents and teachers
A popular explanation says air over the wing must ‘catch up’ with air underneath, but that idea is a myth. A fuller picture combines Newton’s third law (the wing turns air downwards) with pressure differences around the wing. Testing paper plane designs together is a good way to talk about changing one thing at a time in an experiment.
Pictures marked “AI generated” were made with AI tools. Ranki and Tanki are AI generated characters. Found a mistake? Write to info@pr-geo.com and we will fix it.
