Trim tab

A trim tab is a small rudder to aileron, elevator or rudder of an airplane. With the trim to control forces for various flight situations can neutralize, eg for different positions of the elevator as a function of the speed or the rudder in the start phase of engine airplanes.

The trim tab moves with the air motor and the large lever arm created by himself, the trailing edge of the rudder, to which it is attached, from the initial neutral position to a new " normal position ". Thus the force on the control stick / on the pedals for this new attitude is neutralized. The trim tab is one of several technologies for setting the trim by means of a control in the cockpit.

A similar effect as the trim tab unfolds common in sports aircraft and helicopter rotor blades bracket edge, usually just a riveted the trailing edge of the rudder / rotor blade plate. The aerodynamic function is the same as the trim tab, but the bracket edge can not be adjusted during flight. Thus, this strap edge is only suitable for compensating for aerodynamic tolerances permanently.