How Wings Create Lift

Newton's Third Law

Deflection Creates Force

A wing deflects air downward. By Newton's third law, if the wing pushes air down, the air pushes the wing up. This is the most intuitive explanation of lift.

A curved wing naturally deflects more air downward than a flat plate

The faster the deflection, the greater the lift force

Bernoulli's Principle

Circulation & Pressure

Flow around a wing creates circulation—faster flow on top, slower on bottom. By Bernoulli's equation, faster flow means lower pressure. The pressure difference is lift.

Upper surface: faster flow → lower pressure

Lower surface: slower flow → higher pressure

Pressure difference acts upward

Potential Flow Theory

Kutta-Joukowski Theorem

The lift force is proportional to the circulation around the wing and the airspeed. This elegant relationship unifies all lift mechanisms and explains why angle of attack matters.

L = ρ × v × Γ (circulation)

Circulation increases with angle of attack

This breaks down at stall (too much angle)