A foldable canard assembly for aircraft which have a device for effecting artificial stability and flight control apparatus. The canard assembly comprises a pair of wing units extendable laterally of the aircraft and adjustable about an axis longitudinally arranged of the aircraft to a position extending downwardly therefrom wherein said wing units cooperate together to form a single fin. The axis is preferably located at the bottom of a forward portion of the aircraft fuselage and the wing units are adjustable as desired between fully extended and fully folded positions. A control device is also provided for modifying the horizontal stabilizer surfaces of the tail unit to modify the lift generated thereby in order to compensate for the lift of the canards and thereby maintain longitudinal vertical stability of the aircraft.

An aircraft includes fuselage flaps which are normally retracted and conform to the configuration of the fuselage and which may be extended outwardly of the fuselage to increase altitude control. The fuselage flaps comprise a first flap positioned rearwardly of the longitudinal center of gravity and hinged on its lower edge about an axis extending upwardly and rearwardly relative to the longitudinal axis of the fuselage. The fuselage flaps also include second and third flaps having their hinge axes aligned with the longitudinal axis of the fuselage and positioned fore and aft of the longitudinal center of gravity of the fuselage. The fuselage flaps further include a fourth and fifth flap aligned with the longitudinal axis of the fuselage at about the longitudinal center of gravity and the fifth flap being hinged to the rear portion of the fourth flap.

An aerodynamic spoiler mounted on the upper forward surface of the fuselage of an aircraft which is equipped to be refueled by another aircraft while in flight. The spoiler counteracts aerodynamic disturbances produced by the refueling boom and the resultant instabilities in pitch in the aircraft receiving fuel. Four species of the spoiler are disclosed and the device may be made retractable to eliminate drag when not in use.

Canards are pivotally mounted on the fuselage of a variable sweep wing jet aircraft and project laterally with respect to the fuselage forwardly of the wings. The canards are positioned and configured to produce pitch control moments about the center of gravity. Thrust-vectoring devices extend from the jet engines of the aircraft for varying the thrust direction of such engines. A control system is mounted in the fuselage and extends to the wings, the canards and the thrust-vectoring devices for controlling the wings in angular positions relative to the fuselage, controlling the canards in rotary position relative to the fuselage and controlling the thrust-vectoring devices to control the thrust direction. The positions are controlled in coordination to overcome pitch departure, deep stall and spin, which might otherwise occur due to lack of nose-down pitch power, while also optimizing supersonic cruise and transonic maneuver performance of the aircraft.

A fixed-wing aircraft with tandem lifting surfaces has monoplane main wings secured in an intermediate area of the fuselage and a horizontal tail surface with at least one stabilizer plane mounted at the tail of the fuselage. A third supporting surface on the fuselage is in tandem arrangement with the other supporting surfaces. The third supporting surface is a canard surface positioned ahead of the center of gravity of the aircraft.