How Planes Fly

A Boeing 747 jet can weigh over 400,000 pounds when it's fully loaded — heavier than 60 elephants! Yet somehow it lifts off the ground, climbs into the sky, and flies for hours. How does something so heavy fly?

By the end of this lesson, you will be able to: - Name the four forces that act on a flying airplane - Explain how a wing's shape helps create lift - Point out the main parts of an airplane and what they do - Build and test your own paper airplane

Look closely at an airplane wing and you'll notice something special: the top is curved and the bottom is flatter. When the plane moves forward, air has to travel over that curved top and under the flatter bottom at the same time. The air moving over the curved top has to speed up, and fast-moving air pushes less hard than slow-moving air. That difference in push creates an upward force called lift, and lift is what carries the plane into the sky.

Every airplane in the sky is being pulled and pushed by four forces at once. Lift pushes the plane up, and weight (gravity) pulls it back down. Thrust — made by the engines — pushes the plane forward, and drag — the air rubbing against the plane — pushes back and slows it down. Think of pushing a friend on a swing: your push is like thrust, and the air resistance slowing the swing down is like drag. When lift is stronger than weight, and thrust is stronger than drag, the plane flies!

Every airplane has key parts that work together. The wings create lift and often hold the engines. The engines make thrust to push the plane forward. The tail, at the back, has small movable pieces that help the pilot steer and keep the plane steady. The cockpit at the front is where the pilot sits and controls the whole airplane.