Definition
The technique of applying the brakes on the main wheels independently — pressing harder on one side than the other — to assist directional control during taxi or the after-landing roll, typically at speeds too low for the rudder alone to be fully effective.
Plain English
Using the left and right brakes by different amounts to help steer the airplane on the ground. Pressing the left brake harder swings the nose left; pressing the right brake harder swings the nose right.
Context Anchor
Used during ground operations, especially in the after-landing roll when the airplane is slowing down and the pilot needs directional control.
Derivation
‘Differential’ comes from Latin differentia, meaning ‘a difference.’ Here it points to the difference in braking force between the two sides — that difference is what produces the turning effect.
Why Pilots Care
Provides directional control when the rudder becomes ineffective at low ground speeds and helps keep the airplane on the runway centerline.
Analogy
It is like slowing one side of a shopping cart more than the other so the cart turns toward the slower side.
Intuition Check
Do not read differential braking as just normal braking. The key idea is unequal braking: one side gets more brake pressure than the other.
Example Sentence 1
As the airplane slowed and the rudder lost effectiveness, the pilot used light differential braking to keep the rollout straight.
Example Sentence 2
In a crosswind landing, light differential braking helped maintain heading after touchdown.