tailplane

A tailplane, also known as the horizontal stabilizer, is a fixed or movable airfoil mounted at the rear of an aircraft. Its primary function is to provide stability about the aircraft’s pitch axis and to carry the elevator, the main pitch control surface. Along with the vertical stabilizer, the tailplane helps establish longitudinal stability and enables trim for steady flight.

Designs vary. A conventional tailplane is a separate horizontal surface attached to the aft fuselage, typically with an elevator on its trailing edge. In an all-moving tailplane, or stabilator, the entire surface moves to control pitch, eliminating a separate elevator. Some aircraft use a T-tail, where the tailplane is mounted high on the vertical stabilizer, above the fuselage. A V-tail replaces the conventional tail with two surfaces forming a V shape that provides both horizontal and vertical stabilizing effects while reducing drag.

Control and trimming: elevator deflection creates a pitching moment, while trim tabs or an auxiliary trim system holds the desired attitude during steady flight, reducing pilot effort. The tailplane is essential for maintaining level flight and stable handling in most conventional aircraft.

Operational considerations: tailplane effectiveness depends on aerodynamic conditions and airflow over the surface. Certain configurations, such as some T-tails, can be vulnerable to deep stall if the tailplane is blanketed by the wing wake at high angles of attack; designers address this with particular spacing, shaping, or auxiliary surfaces.

History: tailplanes have been a standard feature on conventional aircraft since the early days of flight, evolving from simple stabilizers to adjustable and all-moving designs to improve stability and control.