How does a Plane fly?
There are over 1,400 flights that depart from Heathrow every day heading to destinations all around the world. But how exactly do these heavy jumbo planes fly? Here is a basic explanation of how planes work.
In order to understand how planes fly you need to know the 4 basic forces that are at work when taking off and landing a flight. They are thrust, drag, lift and weight.
Thrust is the aerodynamic force that pushes the plane forward. This is often created by the engines in the plane. In order to move forward though it needs to be stronger than the force that is pulling it back, the drag.
Drag is the resisting of the thrust or the air that is needed to move the plane forward. An everyday example of drag is when you stick your hand out of the window while the car is moving. You are creating drag but the amount of drag depends on the size of your hand, speed of the car and the air density. In order to reduce drag the planes retract the landing gear which make the plane smaller leading to less drag.
Lift of the plane into the air occurs when the plane has enough forward motion through thrust. But the weight of the plane will be working against the lift, pulling it back down. Thankfully the wings aka airfoil assist in lifting the plane.
The weight is the amount of pull of gravity an object has towards the center of the earth. Planes that are larger and going long distances will have a much higher weight than domestic flights due to luggage, fuel and other factors. You can experience the pull of gravity by jumping up in the air. Rather than floating in the air, your weight will bring you back down.
In summary, the thrust needs to be stronger than the drag in order for the plane to move forward. This needs to happen at the same time the lift is stronger than the weight. If all of this works together the plane should be up and away in no time.