Systems and methods for increasing lift of an aircraft lifting surface, may include: a leading-edge assembly; a plurality of high-lift propellers, coupled to the slat assembly and configured to be stowed within a compartment of the lifting surface; a high-lift motor to provide motive force to at least one of the plurality of the high-lift propellers; and a deployment linkage configured to move the slat assembly and plurality of high-lift propellers between a deployed configuration and a stowed configuration, wherein in the stowed configuration the high-lift propellers are stowed within the compartment of the lifting surface and at least a portion of the slat assembly covers the compartment of the lifting surface, and in the deployed configuration the high-lift propellers are positioned external to the aircraft lifting surface to direct airflow from the high-lift propellers past the leading-edge assembly.

An aircraft equipped with a distributed fan propulsion system and methods of operating such aircraft are provided. In one aspect, an aircraft includes a wing having a top surface and a bottom surface. The aircraft also has a distributed propulsion system that includes a suction fan array having one or more fans mounted to the wing and a pressure fan array having one or more fans mounted to the wing. The fans of the suction fan array are each positioned primarily above the top surface of the wing and the fans of the pressure fan array are each positioned primarily below the bottom surface of the wing. The fans of the suction fan array are controllable independent of the fans of the pressure fan array so that the air pressure above and/or below the wing can be locally controlled, allowing for adjustment of lift on the wing.

An aircraft equipped with a distributed fan propulsion system and methods of operating such aircraft are provided. In one aspect, an aircraft includes a wing having a top surface and a bottom surface. The aircraft also has a distributed propulsion system that includes a suction fan array having one or more fans mounted to the wing and a pressure fan array having one or more fans mounted to the wing. The fans of the suction fan array are each positioned primarily above the top surface of the wing and the fans of the pressure fan array are each positioned primarily below the bottom surface of the wing. The fans of the suction fan array are controllable independent of the fans of the pressure fan array so that the air pressure above and/or below the wing can be locally controlled, allowing for adjustment of lift on the wing.

A vertical takeoff and landing (VTOL) aircraft, configured to transport passengers and/or cargo, uses propellers during vertical flight and wings during forward flight to generate lift. The VTOL aircraft includes a front wing and a rear wing connected by inboard booms. The rear wing may include a wingtip boom attached to each free end of the wing. A propeller may be attached to each inboard boom and each wingtip boom. The propellers attached to the inboard booms may be stacked propellers including at least two co-rotating propellers. The aircraft can also include a cruise propeller attached to the tail region of the fuselage, where the cruise propeller is configured to rotate in a plane approximately perpendicular to the fuselage to generate thrust during forward flight.

A vertical takeoff and landing (VTOL) aircraft, configured to transport passengers and/or cargo, uses propellers during vertical flight and wings during forward flight to generate lift. The VTOL aircraft includes a front wing and a rear wing connected by inboard booms. The rear wing may include a wingtip boom attached to each free end of the wing. A propeller may be attached to each inboard boom and each wingtip boom. The propellers attached to the inboard booms may be stacked propellers including at least two co-rotating propellers. The aircraft can also include a cruise propeller attached to the tail region of the fuselage, where the cruise propeller is configured to rotate in a plane approximately perpendicular to the fuselage to generate thrust during forward flight.

An aircraft equipped with a distributed fan propulsion system and methods of operating such aircraft are provided. In one aspect, an aircraft includes a wing having a top surface and a bottom surface. The aircraft also has a distributed propulsion system that includes a suction fan array having one or more fans mounted to the wing and a pressure fan array having one or more fans mounted to the wing. The fans of the suction fan array are each positioned primarily above the top surface of the wing and the fans of the pressure fan array are each positioned primarily below the bottom surface of the wing. The fans of the suction fan array are controllable independent of the fans of the pressure fan array so that the air pressure above and/or below the wing can be locally controlled, allowing for adjustment of lift on the wing.

An ionic propulsion system for an aircraft having an airfoil includes a first conductor and a second conductor, the first conductor and the second conductor being disposed at least partially within the airfoil when not in use. The propulsion system includes an actuator for extending the first conductor and the second conductor from an end of the airfoil such that the first conductor and the second conductor are in the airstream of the aircraft, the first conductor being upstream of the second conductor in the airstream. The propulsion system includes a power supply for supplying current to the first conductor and the second conductor to ionize the air particles in the vicinity of the first conductor and the end of the airfoil to create a flow of the ionized particles from the first conductor toward the second conductor.

Braking systems for aircraft are disclosed. An example braking system includes a fan cowl having a leading edge and a trailing edge. The braking system includes a hinge assembly coupled between the leading edge and a fan cage of an aircraft engine to enable the fan cowl to move between a stowed position and a deployed position. An actuator is coupled to the leading edge of the fan cowl, and the actuator is to move the fan cowl via the hinge from the stowed position to the deployed position in a direction away from the aircraft engine and toward a fore end of the aircraft to provide an air brake during a braking event.

Braking systems for aircraft are disclosed. An example braking system includes a fan cowl having a leading edge and a trailing edge. The braking system includes a hinge assembly coupled between the leading edge and a fan cage of an aircraft engine to enable the fan cowl to move between a stowed position and a deployed position. An actuator is coupled to the leading edge of the fan cowl, and the actuator is to move the fan cowl via the hinge from the stowed position to the deployed position in a direction away from the aircraft engine and toward a fore end of the aircraft to provide an air brake during a braking event.

The invention concerns an aircraft propulsion system comprising at least one member (1, 3, 4, 8) in contact with a turbulent flow of a stream (F), characterised in that said member is covered, at least partially, by a piezoelectric structure (S) such as a piezoelectric film, said structure (S) comprising a grooved structure (5, 6, 7, 9) comprising a series of grooves, in contact with the flow of the stream, the grooves extending in the direction of flow of the stream, the grooved structure comprising at least one geometric parameter (h, s, w) configured to adapt depending on at least one parameter of the flow of the stream and/or an operating point of the propulsion system and/or an engine speed of the propulsion system.