Rudder pedals are foot-operated flight-control interfaces that, when pressed, deflect the rudder, the movable surface hinged to the trailing edge of the vertical stabilizer. By producing an aerodynamic force, the pedals move the rudder and thus command rotation about the aircraft's vertical axis - commonly called yaw.
Expert behind this article
Jim Goodrich
Jim Goodrich is a pilot, aviation expert and founder of Tsunami Air.
What are rudder pedals in aircraft?
A rudder pedal is a foot-operated aircraft flight control interface for controlling the rudder of an aircraft; when a pilot presses the left rudder pedal forward, the arm rotates clockwise and the rudder rotates in the same direction as the arm connecting the two rudder pedals. Wheel brakes are activated by pressing down on the top of the rudder pedals.
Rudder pedals are a part of flight deck controls. The pedal set consists of a pair of pedals, one pedal for each foot. Each pedal is connected to the rudder, a primary flight control surface mounted on the trailing edge of the vertical stabilizer. The rudder controls rotation about the vertical axis of an aircraft and this movement is referred to as yaw. Yaw rotates the airplane around the vertical axis, helping the pilot maintain directional control.
In a helicopter, rudder pedals are more accurately called anti-torque pedals. Anti-torque pedals control the pitch of the tail rotor. By increasing or decreasing the thrust of the tail rotor, the pilot can rotate the helicopter about its vertical axis. This allows for precise directional control during hover and low-speed flight.
Do all planes have rudder pedals?
No, all planes do not have rudder pedals. Most airplanes do have rudder pedals and the flight-control system relies on them so the pilot can command yaw. In the cockpit, both pilot and copilot have their own pair of rudder pedals. The Ercoupe lacks rudder pedals altogether. This small plane was flown using only the control wheel due to a two-control system that linked the rudder and aileron surfaces. Because the control wheel managed both roll and yaw, no pedal input was required, and the twin rudders moved automatically with aileron deflection.
A few other small planes have alternative rudder controls, but these are rare. Commercial transports, multi-engine planes, and the majority of light singles like the Piper Cherokee and C182 have real rudder pedals. On larger aircraft, a three-axis autopilot will apply rudder as needed, and yaw dampers mitigate undesirable flight characteristics, yet the pedals remain present for manual command.
How do airplane rudder pedals work?
Rudder pedals work by altering the direction of the rudder swing. Pressing the bottom part of the pedals slides them back and forth on tracks; Pressing the left rudder pedal causes rudder deflection to the left whereas pressing the right rudder pedal causes rudder deflection to right. The rudder control system translates pedal movements into rudder deflection through mechanical or hydraulic linkages. Hydraulic actuators are often used in large or high speed aircraft to help overcome mechanical and aerodynamic loads on the rudder surface. Transmitting a control linkage force transmission to the rudder causes it to deflect. Rudder deflection changes the flow around the vertical stabilizer. and creates side force perpendicular to direction of motion. The side force generates a yawing moment. Yaw is rotation of the aircraft around the vertical axis. Deflecting airflow at the tail to the left yaws the plane to the left and deflection of airflow at tail to the right yaws the plane to right.
How to use airplane rudder pedals?
To steer during taxi the pilot presses the top part of the rudder pedals to activate the individual brake pedals: differential toe-brakes apply braking to a single wheel which causes the plane to turn, and in calm wind conditions yoke control is often not required. Pedal force is light; MIL F 8785 B limits rudder pedal force to 50 lbs f (22.68 kg-f), and a typical maneuver needs only half rudder applied over about a second to initiate a turn.
During stalls, I utilize the rudder foot lever solely for directional guidance. I implement the correct control surface to countervail the left-turning movement induced by motor force and the rotating blade. By keeping the aircraft from sliding, this allows for a streamlined, effective flying route.
Jim GoodrichPilot, Airplane Broker and Founder of Tsunami Air
