Plain English Meaning

When the wings tilt in a bank, part of the lift no longer points straight up. Some of it points sideways, and that sideways pull is what makes the airplane turn.

Full Definition

The sideways portion of the total lift force produced by the wings when the airplane is banked. When an airplane rolls into a bank, the lift vector tilts with it, splitting into two parts: a vertical component that opposes weight, and a horizontal component that acts toward the inside of the turn. This horizontal component is the force that pulls the airplane into a curved path and is what actually causes the airplane to turn.

Context Anchor

Seen in discussions of slips, banks, and turns, especially when explaining why a banked airplane tends to turn unless rudder is used to control its direction.

Derivation

‘Horizontal’ comes from ‘horizon’, meaning level with the . ‘Component’ comes from Latin componere, ‘to put together’, and in means one of the parts a force can be into. So ‘horizontal component of lift’ means the part of lift that points sideways rather than upward.