A control system operable includes a modified primary control parameter for an aircraft, the control system includes: a primary control parameter leg configured to output a demand in an aircraft primary control parameter; a primary control parameter compensation leg configured to receive a change in absolute levels and/or spatial distributions of swirl angle and/or fan pressure at a primary control parameter relative to a reference and convert the change into the primary control parameter; a processor adapted to receive the demand in the primary control parameter output from the primary control parameter leg and the change to the primary control parameter output from the primary control parameter compensation leg; compare the demand in the primary control parameter output from the primary control parameter leg and the change to the primary control parameter output from the primary control parameter compensation leg; and generate a modified primary control parameter for the aircraft.

A cross flow fan to be incorporated into an aircraft comprises a cross flow fan rotor to be positioned in an aircraft, a drive arrangement for the cross flow fan rotor, and a plurality of vanes positioned downstream of the cross flow fan rotor. An aircraft is also disclosed.

A structure ensuring acoustic attenuation of a flow of a first fluid and heat exchange between a first fluid and a second fluid. The structure includes a first wall which is perforated, a second wall, and a plurality of intermediate walls extending between the first wall and the second wall. For each intermediate wall, there is a pipe intended to receive the second fluid and inscribed within the intermediate wall. Such a structure makes it possible to optimally integrate the acoustic wave attenuation function and the heat exchange function.

A structure ensuring acoustic attenuation of a flow of a first fluid and heat exchange between a first fluid and a second fluid. The structure includes a first wall which is perforated, a second wall, and a plurality of intermediate walls extending between the first wall and the second wall. For each intermediate wall, there is a pipe intended to receive the second fluid and inscribed within the intermediate wall. Such a structure makes it possible to optimally integrate the acoustic wave attenuation function and the heat exchange function.

An aerodynamic structure for use on an upper surface of an aircraft wing is disclosed. The wing includes a slat operable between a stowed configuration in which the slat is stowed in a slat recess of the wing, and a deployed configuration in which the slat extends out of the slat recess. When the slat is in the deployed configuration, an end face of the slat recess is exposed, the end face intersecting with the upper surface of the wing at a recess edge. The aerodynamic structure, adjacent to the recess edge, has a volume shaped to encourage air flowing over the recess edge onto the upper surface during flight, to remain attached.

An aerodynamic structure for use on an upper surface of an aircraft wing is disclosed. The wing includes a slat operable between a stowed configuration in which the slat is stowed in a slat recess of the wing, and a deployed configuration in which the slat extends out of the slat recess. When the slat is in the deployed configuration, an end face of the slat recess is exposed, the end face intersecting with the upper surface of the wing at a recess edge. The aerodynamic structure, adjacent to the recess edge, has a volume shaped to encourage air flowing over the recess edge onto the upper surface during flight, to remain attached.

A boundary-layer-influencing aerodynamic part comprises a carrier element provided with at least one air passage aperture for guiding an air flow through the carrier element, an air guiding layer disposed on the carrier element and a cover layer constituting at least a part of a flow surface and being configured to have air flow there through at least in sections. The air guiding layer is configured to have air flow there through with an air flow supplied to the part, at least in certain operating phases of the part, through the cover layer and flowing in the direction of the carrier element or through the air passage aperture of the carrier element and flowing in the direction of the cover layer. The cover layer is applied directly to the air guiding layer via an additive manufacturing method.

A vortex generator system has at least two vortex generators protrudable from an outer mold line of a vehicle surface at a location upstream of a cavity leading edge of a cavity in the vehicle surface. The vortex generators are spaced apart from each other and oriented such that the vortex generator aft ends are nearer to each than the vortex generator forward ends. The vortex generator lengthwise direction of each one of the vortex generators is oriented at a vortex generator directional angle relative to a direction of an airflow. The vortex generators are configured to generate a pair of counter-rotating vortices when the airflow passes over through or over the vortex generators. The counter-rotating vortices interact to produce a downwash of air away from the cavity that urges the store away from the vehicle as the store exits the cavity.

A vortex generator system has at least two vortex generators protrudable from an outer mold line of a vehicle surface at a location upstream of a cavity leading edge of a cavity in the vehicle surface. The vortex generators are spaced apart from each other and oriented such that the vortex generator aft ends are nearer to each than the vortex generator forward ends. The vortex generator lengthwise direction of each one of the vortex generators is oriented at a vortex generator directional angle relative to a direction of an airflow. The vortex generators are configured to generate a pair of counter-rotating vortices when the airflow passes over through or over the vortex generators. The counter-rotating vortices interact to produce a downwash of air away from the cavity that urges the store away from the vehicle as the store exits the cavity.

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).