>[!abstract] >Trim tabs are small surfaces connected to the trailing edge of a larger control surface on an aircraft [typically, elevators at the trail edge of the horizontal stabilizer], used to adjust the trim of the controls, i.e. to counteract aerodynamic forces and stabilize the aircraft in a particular desired attitude without the need for the operator to constantly apply a control force. This is done by adjusting the angle of the tab relative to the larger surface. (Wikipedia, 2025). The main types of tabs are: - **Normal or plain trim tabs** are meant to keep the aircraft in a constant pitch-up or pitch-down attitude. Turning the trim wheel up lowers the trim tab, which creates an upward force on the tail and thus a downward force on the nose of the aircraft (pitch-down attitude). Turning the trim wheel down raises the trim tab, which creates a downward force on the tail and thus an upward force on the nose of the aircraft (pitch-up attitude). - **Balance tabs** which look like trim tabs, but move automatically in the *opposite* direction of the primary control surface. The balance tab causes an opposite moment in the primary control surface, which makes its deflection easier for the pilot by reducing the force required on the control column. - **Antiservo tabs** are similar to balance tabs but move automatically in the *same* direction as the primary control surface. They are meant to *increase* the amount of force required by the pilot to deflect control surfaces, and therefore decrease the amount of aerodynamic stress on the structure. - **Ground-adjustable tabs** are small, fixed tabs at the lower end of the rudders of smaller aircraft. They are meant to compensate for the single propeller's gyroscopic effect (yawing moment) and neutralize the light skid during cruise flight. >[!related] >- **North** (upstream): — >- **West** (similar): — >- **East** (different): — >- **South** (downstream): [[Call me trim tab]]