Systems: Flight Controls

Primary Flight Controls

• Purpose: Control the aircraft’s basic movement about the three axes (pitch, roll, and yaw). They are essential for safe flight.
• Components:
  1. Ailerons: Control roll (longitudinal axis).
  2. Elevator (or Stabilator): Controls pitch (lateral axis).
  3. Rudder: Controls yaw (vertical axis).
• Characteristics:
  • Directly affect the aircraft’s attitude and trajectory.
  • Always functional and required for flight.

Secondary Flight Controls

• Purpose: Improve performance, efficiency, and comfort; reduce pilot workload.
• Components:
  1. Flaps: Increase lift and drag, used primarily during takeoff and landing.
  2. Trim Systems: Relieve control forces on the primary flight controls (e.g., elevator trim).
  3. Spoilers (in some aircraft): Reduce lift and increase drag.
  4. Leading Edge Devices (in advanced aircraft): Enhance lift at lower speeds.
• Characteristics:
  • Not required for basic flight but enhance performance and ease of control.
  • Used situationally, such as during climbs, descents, or landings.

Summary

• Primary: Essential for controlling the aircraft (ailerons, elevator, rudder).
• Secondary: Assist and optimize performance (flaps, trim, spoilers).
• Flight controls are powered via cables and pulleys, and occasionally there may be a “push-pull” rod instead of cables to actuate them.  On our small Cessna and Piper aircraft they are never electric or hydraulic.  The only thing that may be electric in the flight controls may be electric trim.  Turning off the master or having an engine failure would not affect the flight controls in any way (other than maybe electric trim, and electric flaps)