Definition
An aileron designed with its hinge line set back from the leading edge so that, when the aileron deflects upward, the leading edge projects below the lower wing surface into the airflow. This projection increases drag on the down-going wing, helping to counteract adverse yaw produced during a roll.
Plain English
A special kind of aileron shape that sticks its nose down into the air when it moves up. That extra bit of drag helps the airplane turn cleanly instead of swinging the nose the wrong way during a roll.
Context Anchor
Encountered in discussions of airplane control surfaces, roll control, and how designers reduce adverse yaw.
Derivation
Named after Leslie George Frise, the British aeronautical engineer who designed this aileron type in the 1930s. Knowing the name is a person's surname helps explain the unusual spelling and the capital F.
Why Pilots Care
The added drag on the rising wing reduces adverse yaw, allowing coordinated turns with less rudder input and improving control harmony.
Intuition Check
Do not read “Frise” as “freeze.” It is not related to ice or cold weather; it is the name of the aileron design.
Example Sentence 1
The trainer's Frise-type ailerons reduced adverse yaw, so only a small amount of rudder was needed to keep the turn coordinated.
Example Sentence 2
During the steep turn, the pilot noticed the airplane stayed coordinated with minimal rudder because of the Frise-type ailerons.