A vehicle includes a main body and a gas generator producing a gas stream. At least one fore conduit and tail conduit are fluidly coupled to the generator. First and second fore ejectors are fluidly coupled to the at least one fore conduit. At least one tail ejector is fluidly coupled to the at least one tail conduit. The fore ejectors respectively include an outlet structure out of which gas from the at least one fore conduit flows. The at least one tail ejector includes an outlet structure out of which gas from the at least one tail conduit flows. First and second primary airfoil elements have leading edges respectively located directly downstream of the first and second fore ejectors. At least one secondary airfoil element has a leading edge located directly downstream of the outlet structure of the at least one tail ejector.

A method of providing ice protection on a surface of an aircraft using exhaust air from a laminar flow control compressor. An aircraft structure, for example a wing, includes a skin. The skin has an external surface, on an outer face of the skin. The skin has an internal surface, located opposite the external surface on an inner face of the skin. The aircraft structure includes a laminar flow control system including a compressor. The aircraft structure is so arranged that the exhaust air from the compressor is directed onto the internal surface of the skin of the aircraft structure, for example thus providing hot exhaust air which function as an ice protection system (whether by de-icing or anti-icing).

An air vehicle is provided including: a main lift generating wing arrangement having a port wing and a starboard wing, empennage and main propulsion system. The air vehicle further includes a distributed electrical propulsion (DEP) system having secondary electrical propulsion units coupled to each one of the port wing and the starboard wing. The main propulsion system is configured for providing sufficient thrust such as to enable powered aerodynamic flight of the air vehicle including at least: powered aerodynamic take off absent operation of the DEP system; and powered aerodynamic landing absent operation of the DEP system. The DEP system is configured for selectively providing at least augmented lift to the main lift generating wing arrangement in at least landing. A method for landing an air vehicle on a moving platform under separated wake conditions is also provided.

A boundary layer control (BLC) system for embedment in a flight surface having a top surface, a bottom surface, a leading edge, and a trailing edge. The BLC system may comprises an actuator having a crossflow fan and an electric motor to drive the crossflow fan about an axis of rotation. The actuator may be embedded within the flight surface and adjacent the leading edge. In operation, the actuator is configured to output local airflow via an outlet channel through an outlet aperture adjacent the top surface to energize a boundary layer of air adjacent the top surface of the flight surface.

The invention relates to an air system for an aircraft, that includes air consumers; air sources and a network of ducts and associated control valves controlled by a control unit. The air system is characterized in that: the network of ducts and associated valves includes at least one isolation valve, arranged between an air bleed device and an air duct connecting an air conditioning pack and an auxiliary power unit; the control unit is configured to be able to determine an ideal configuration of the control valves according to the identified requirements of each consumer and a degraded configuration that makes it possible to supply air to predetermined air consumers from the available air sources when the ideal configuration is not attainable.

A boundary layer ingestion fan system for location aft of the fuselage of an aircraft is shown. It comprises a nacelle (501) defining a duct, and a fan located therewithin. The fan comprises a hub arranged to rotate around a rotational axis (A-A) and a plurality of blades attached thereto. Each blade has a span (r) from a root at the hub defining a 0 percent span position (r=0) to a tip defining a 100 percent span position (r=1) and a plurality of span positions therebetween (r ∈ [0, 1]), and leading and trailing edges defining, for each span position, a chord therebetween to having a chord length (c). For each of said plurality of blades, the ratio of chord length at the 0 percent span position (c.sub.hub) to chord length at the 100 percent span position (c.sub.tip) is 1 or greater.

Air acceleration at slot of aircraft wing. In one embodiment, a wing includes an air duct configured to transport air in a spanwise direction along a leading edge of the wing from an air supply source of the aircraft. The wing further includes a discharge duct configured to transport the air in an aft direction from the air duct to an aft end of the wing, and one or more nozzles disposed on the aft end of the wing and configured to accelerate air into a slot between the wing and a flap of the aircraft to increase lift and reduce drag for the wing.

A boundary layer ingestion fan system for location aft of the fuselage of an aircraft includes a nacelle (501) defining a duct (502), and a fan (503) located therewithin. The fan comprises a hub which rotates around a rotational axis (A-A) and a plurality of blades attached thereto. Each blade has a span (r) from a root at the hub defining a 0 percent span position (r=0) to a tip defining a 100 percent span position (r=1) and a plurality of span positions therebetween (r∈[0, 1]), a leading edge and a trailing edge defining, for each span position, a chord therebetween having a chord length (c), and a blade thickness (t) defined for each span position thereof. For each blade, a ratio of thickness at the 0 percent span position (t.sub.hub) to chord length is 0.1 or greater.

A boundary layer ingestion fan system for location aft of the fuselage of an aircraft is shown. It comprises a nacelle defining a duct, and a fan located within the duct. The fan comprises a hub arranged to rotate around a rotational axis (A-A) and a plurality of blades attached to the hub, each of which has a span from a root at the hub defining a 0 percent span position (r.sub.hub) to a tip defining a 100 percent span position (r.sub.tip) and a plurality of span positions therebetween (r∈[r.sub.hub, r.sub.tip]). A hub-tip ratio of the fan, defined as the ratio of the diameter of the hub to the diameter of the fan measured at the leading edge of the blades, is from 0.45 to 0.55.

A flow guide body for an aircraft includes a main body having an outer aerodynamic surface having a plurality of outlet openings, and flow control devices, each having an inlet, an interaction chamber, a first outlet and a second outlet. A first control inlet is connected to the interaction chamber at the first side of the chamber axis. The outlets are each connected to outlet openings in the aerodynamic surface. Each outlet has a control outlet. A second flow control device is arranged such that one outlet is connected with the inlet of the first flow control device. One of the control outlets of the first flow control device is connected to the first control inlet of the first flow control device, and the other of the control outlets of the first flow control device is connected to the first control inlet of the second flow control device.