Definition
One of two foot-operated controls in the cockpit, mounted on the cockpit floor, that the pilot uses to deflect the rudder left or right and thereby control yaw — the side-to-side movement of the airplane's nose around its vertical axis. On most airplanes the rudder pedals also operate the nosewheel or tailwheel steering for ground handling, and the upper portion of each pedal applies the brake on the corresponding main wheel.
Plain English
The two pedals at your feet that swing the airplane's nose left or right. Push the left pedal, the nose swings left; push the right pedal, the nose swings right. On the ground these same pedals usually steer the airplane and, by pressing the tops, apply the brakes.
Context Anchor
Seen when learning the primary flight controls and during taxi, takeoff, landing, turns, and recovery from unwanted left-right nose movement.
Derivation
‘Rudder’ comes from the Old English rōther, meaning a paddle or steering oar used on boats. Early aircraft borrowed the nautical term because the airplane's rudder steers the nose left and right in a similar way. The pedal is simply the foot-operated lever that moves it.
Why Pilots Care
Correct rudder-pedal use maintains directional control, counters crosswinds, and manages left-turning tendencies such as P-factor and torque.
Intuition Check
Do not think of the rudder pedal as a car steering wheel for the air. It does not bank the airplane; it moves the nose left or right and helps keep the airplane lined up and balanced.
Example Sentence 1
On the takeoff roll, the student applied steady right rudder pedal pressure to keep the nose tracking down the centerline.
Example Sentence 2
In the climb, right rudder pedal input was needed to offset the airplane's left-turning tendency.