Definition of "control surface" []

• A movable airfoil, especially a rudder, aileron, or elevator, used to control or guide an aircraft, guided missile, or rocket. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Instantaneously, he thought about the loss of the small fuel tank at the tip of his right wing the “tip tank”, plus the serious damage to his starboard aileron, the moveable control surface attached to the trailing edge of the wing."