by the deflected ailerons may add further to the difference, along with changes in the lift vectors as one rotates back while the other rotates forward. In a coordinated turn, adverse yaw is effectively compensated by the use of the rudder, which results in a sideforce on the vertical tail that opposes the adverse yaw by creating a favorable yawing moment. Another method of compensation is 'differential ailerons', which have been rigged so that the down-going aileron deflects less than the up-going one. In this case the opposing yaw moment is generated by a difference in profile drag between the left and right wingtips. Frise ailerons accentuate this profile drag imbalance by protruding beneath the wing of an upward-deflected aileron, most often by being hinged slightly behind the leading edge and near the bottom of the surface, with the lower section of the aileron surface's leading edge protruding slightly below the wing's undersurface when the aileron is deflected upwards, substantially increasing profile drag on that side. Ailerons may also be designed to use a combination of these methods. With ailerons in the neutral position, the wing on the outside of the turn develops more lift than the opposite wing due to the variation in airspeed across the wing span, which tends to cause the aircraft to continue to roll. Once the desired angle of bank (degree of rotation about the longitudinal axis) has been obtained, the pilot uses opposite aileron to prevent the angle of bank from increasing due to this variation in lift across the wing span. This minor opposite use of the control must be maintained throughout the turn. The pilot also uses a slight amount of rudder in the same direction as the turn to counteract adverse yaw and to produce a "coordinated" turn wherein the fuselage is parallel to the flight path. A simple gauge on the instrument panel called the slip indicator, also known as "the ball", indicates when this coordination is achieved. Aileron components Horns and aerodynamic counterbalances Particularly on larger or faster aircraft, control forces may be extremely heavy. Borrowing a discovery from boats that extending a control surface's area forward of the hinge lightens the forces needed first appeared on ailerons during World War I when ailerons were extended beyond the wingtip and provided with a horn ahead of the hinge. Known as overhung ailerons, possibly the best known examples are the