Definition
The control input applied to the ailerons by deflecting the control wheel or stick toward one wing, used during a crosswind takeoff roll to keep the upwind wing from lifting. Full deflection is held into the wind at the start of the takeoff roll and gradually reduced as airspeed builds and the ailerons become more effective.
Plain English
Holding the control wheel turned into the wind during a crosswind takeoff, so the wing on the windy side stays down. As the airplane speeds up and the controls bite better, you ease off how far you're holding it.
Context Anchor
Encountered during crosswind takeoff technique, especially while the airplane is rolling down the runway before liftoff.
Derivation
Aileron comes from the French aileron, meaning 'little wing.' Pressure here refers to the steady control force the pilot applies, not air pressure. Together it describes the pilot's sustained input on the wing-tilting controls.
Why Pilots Care
Correct aileron pressure keeps the upwind wing from rising in a crosswind, preserving directional control until the aircraft is airborne.
Grounding Statement
On the takeoff roll in a crosswind, the wind can try to raise the upwind wing, and aileron pressure is the pilot’s hand force that helps keep that wing down.
Intuition Check
Pressure does not mean air pressure here. It means the physical force the pilot applies to the control wheel or stick.
Example Sentence 1
With a left crosswind, the pilot held full left aileron pressure as the takeoff roll began, then gradually reduced it as the airplane accelerated.
Example Sentence 2
As airspeed increases, gradually reduce aileron pressure so the controls do not overbank the aircraft on liftoff.