The physics of flight

Welcome! I'm excited to explore the physics of flight with you. Before we dive into the forces that keep a 400-ton metal tube floating gracefully in the air, I'd love to learn a little bit more about you so I can tailor our conversation.

What is your main goal for learning about the physics of flight, and do you have any background in physics or aviation?

I'm just curious and starting from scratch!

It is wonderful to have you here! Starting completely from scratch is actually the absolute best way to learn, because we can build a rock-solid foundation without any confusing jargon getting in the way.

Your path

How Wings Generate Aerodynamic Lift

Angle of Attack and Stalls

Drag Components and Aircraft Stability

The Four Forces of Flight

To understand how a massive airliner defies gravity, we have to look at a constant, invisible tug-of-war. At any given moment in the air, an airplane is being pulled in four different directions by four primary aerodynamic forces.

A passenger airplane in mid-flight with four color-coded cardinal force vectors representing Lift, Weight (Gravity), Thrust, and Drag acting at its center of gravity.

As you can see in the diagram, these forces form two opposing pairs. Let's break down exactly what each of these players does in our aerial tug-of-war:

Thrust is the forward force. It is generated by the airplane's engines (whether they are jet engines or spinning propellers) pushing air backward, which in turn pushes the plane forward.
Drag is the backward force. It is the friction and air resistance that the plane encounters as it slices through the atmosphere. Think of how it feels to push your hand through water; that resistance is drag.
is the downward force. This is simply the gravitational pull of the Earth drawing the mass of the airplane down toward the ground.
Lift is the upward force. It is generated by the movement of air over the airplane's wings, acting as the magical upward push that counteracts the weight.