Elevons

An elevon is a type of aircraft control surface that combines the function of an elevator and an aileron on tailless aircraft. Positioned on the trailing edge of a wing, elevons deflect upward or downward to produce pitch changes (symmetrical deflection) and can deflect differentially to produce roll moments (asymmetric deflection). Because tailless designs lack a separate horizontal tail, elevons provide both pitch and roll control in a single surface arrangement.

Elevons are commonly used on flying wings and delta-wing aircraft. Their deflection is typically driven by a flight control system that blends the pilot’s input for pitch and roll into the appropriate elevon movements, using mechanical linkages or electronic flight controls. Some configurations also employ spoilers or flaps in conjunction with elevons to increase stability or control authority at low speeds or high angles of attack.

Advantages of elevons include reduced aerodynamic drag and structural weight, as well as the ability to realize tailless designs with lower radar signatures. They can simplify the airframe by eliminating separate horizontal stabilizers. Challenges include more complex control dynamics, especially near stall or in aggressive maneuvers, where mixed surface deflections can produce nonlinear responses. Modern fly-by-wire systems typically manage mixing and command limits to maintain stable handling.

Notable implementations appear on tailless and delta-wing aircraft such as the flying-wing B-2 Spirit and various historical tailless designs that rely on elevons for primary pitch and roll control.