Lift pushes a plane up, weight pulls it down, thrust pushes it forward and drag pulls it back. These are the four forces of flight.
Wings make lift, the force that holds the plane up in the air. Weight is the pull of gravity that tries to bring the plane down toward the ground.
Engines make thrust, a push that moves the plane forward through the air. Some planes use propellers, instead of jets, to push them through the air.
The air pushes back against a moving plane. This push is called drag.
A plane needs enough lift from its wings to beat its weight. It also needs enough thrust from its engines to beat its drag.
A plane has to move for its wings to make lift. A plane that is not moving through the air makes no lift. Lift only works where there is air.
A pilot steers a plane by moving parts on its wings and tail. The tail helps keep the plane's nose pointing straight ahead.
Ailerons are the hinged parts on the back edge of each wing. One goes up while the other goes down, and the plane rolls.
The rudder turns a plane's nose left or right. A pilot uses the rudder together with the ailerons to turn the plane.
Flaps are hinged parts on the back of the wings. On takeoff and landing they tilt down to give the wings more lift.
Wilbur and Orville Wright took turns flying on December 17, 1903. They made four flights that day.
The first flight lasted only 12 seconds. It went 120 feet.
Words to know
- thrust: a push forward
- drag: air pushing back
- ailerons: wing parts
- rudder: tail turning part
- flaps: hinged wing parts
