Definition
The force a pilot applies with the feet to one of the rudder pedals to deflect the rudder, controlling the airplane's yaw (nose left or right) about its vertical axis. The amount of pressure -- not the distance the pedal travels -- is what pilots are trained to feel and modulate.
Plain English
How hard you push on a rudder pedal with your foot to swing the airplane's nose left or right.
Context Anchor
Seen in discussions of airplane stability and control, especially when describing how much pedal force is needed to keep the airplane pointed where the pilot wants.
Derivation
Rudder comes from an old word for a steering oar on a boat. Pressure comes from Latin words meaning “to press.” Together, the term points to the pilot pressing on the steering control that helps point the airplane’s nose left or right.
Why Pilots Care
Correct rudder pressure prevents slips or skids, reduces drag, and helps maintain control during turns, stalls, and other maneuvers.
Intuition Check
Pressure here does not mean air pressure or hydraulic pressure. It means the physical push from your foot on a rudder pedal, or the push the pedal gives back to your foot.
Example Sentence 1
During the crosswind landing, the instructor reminded the student to use steady right rudder pressure to keep the nose aligned with the runway centerline.
Example Sentence 2
During stall recovery, the instructor reminded the student to apply rudder pressure smoothly to center the ball.