How it works
When the pilot moves the stick or yoke laterally, one aileron deflects down and the other deflects up simultaneously. Deflecting an aileron changes the effective camber of that wing section, which changes the lift it produces.
The wing with the down-deflected aileron produces more lift and rises. The wing with the up-deflected aileron produces less and drops. The aircraft rolls toward the dropping wing — the low wing in the direction the pilot commanded.
Quick reference
| Controls | Roll (longitudinal axis) |
| Location | Trailing edge of each wing, typically near the wingtip |
| Movement | Differential pair — one up, one down simultaneously |
| Pilot input | Lateral stick or yoke movement |
Adverse yaw: The down-deflected aileron (higher lift) also produces more drag, pulling the nose away from the intended turn. Pilots counter this with rudder input, and designers reduce it with differential deflection (down aileron moves less than up) or Frise ailerons (up aileron exposes a lip that adds drag to the rising wing).