Trim Tabs: What They Are and What They Do
admin on September 25th, 2011
Small surfaces called trim tabs are connected to the trailing edge of a bigger control surface on an airplane such as its rudder, elevators, or ailerons. The trim tabs counter aerodynamic forces and stabilize the airplane in a desired position without having the operator continually apply a control force to the particular control surface. This action is made by tweaking the angle of the trim tab in relation to the larger control surface.
If used correctly, the trim tabs will allow the operator to significantly reduce the manual force needed to maintain a desired position of a control surface. Trim tab controls are lighter and easier to enable the adjustments on the trim tabs, thus acquiring the desired positions of the larger control surface at practically zero force.
All aircraft must have a system for ensuring trim in the longitudinal axis and many airplanes have trim tabs on their elevators as a simple method of providing trim in the longitudinal axis to free the pilot from exerting constant pressure on the pitch controls. The trim tab control used is usually in a form of a vertical wheel rotated forward and backward. When rotated forward, the airplane nose is held down; otherwise, moving the trim wheel back, the tail becomes heavy and the plane tilts down.
The above example is also employed to the rudder and the airplane’s ailerons found on the wings. Trim tabs on these control surfaces drastically lessen the pilot’s workload during maneuvers, letting them to attend to other tasks like communication with air traffic control as well as traffic avoidance.
Aside from reducing the workload of the pilot, the use of trim tabs also reduces the airplane drag, known to be the effect of air resistance or fluid resistance. This resultant proper trim increases fuel efficiency and, of course, smoother ride. Trim tabs are real fine tuners of the aircraft.
