Abstract: An air purifying system for an indoor space includes a plurality of air purifying sites, each one of the plurality of air purifying sites configured to treat a sub-volume of the total volume of air in the indoor space, wherein each one of the plurality of air purifying sites includes a housing, an air inlet configured to direct treatment air having gaseous and non-gaseous components from the indoor space into the housing, a purifier carried within the housing, an air outlet configured to direct the treatment air that has passed through the purifier into the indoor space, and an air mover configured to move air between the air inlet and the air outlet, through the purifier, wherein the plurality of air purifying sites is configured to work cooperatively with a central air system of the indoor space.

Abstract: A wing tip device for a fixed wing aircraft is disclosed having an alular-like projection, a first leading edge region having a first sweep angle, a second leading edge region outboard of the first leading edge region in a spanwise direction and having a second sweep angle greater than the first sweep angle, a third leading edge region outboard of the second leading edge region in the spanwise direction and adjacent a tip end of the wing tip device and having a third sweep angle greater than the first sweep angle. The second leading edge region is adapted to generate a first vortex, and the third leading edge region is adapted to generate a second vortex which builds towards the tip end of the wing tip device.

Abstract: A wing tip device for a fixed wing aircraft is disclosed having an alular-like projection, a first leading edge region having a first sweep angle, a second leading edge region outboard of the first leading edge region in a spanwise direction and having a second sweep angle greater than the first sweep angle, a third leading edge region outboard of the second leading edge region in the spanwise direction and adjacent a tip end of the wing tip device and having a third sweep angle greater than the first sweep angle. The second leading edge region is adapted to generate a first vortex, and the third leading edge region is adapted to generate a second vortex which builds towards the tip end of the wing tip device.

Abstract: An aircraft comprising a wing; a tractor propulsion means (TPM); a pusher propulsion means (PPM); a cruising propulsion means (CPM); and wherein the TPM is capable of providing a thrust, the direction of thrust reversibly movable from a forward propelling direction, to an upward propelling direction; and wherein the PPM is capable of providing a thrust, the direction of thrust reversibly movable from a forward propelling direction, to an upward propelling direction; and wherein the CPM is capable of providing a thrust, the direction of thrust being in a forward propelling direction; and wherein the TPM and PPM are connected to the wing, and wherein the TPM is located in fore of the wing and the PPM is located in aft of the wing.

Abstract: An aircraft fuel vent pipe with a pipe body containing a duct which extends along a duct axis between an open end and a closed end. A burst disc closes the closed end of the duct. One or more devices are provided in the duct, the device(s) being positioned or shaped to enable the burst disc to be visually inspected by looking along the duct through its open end, and to modify a sectional profile of the duct transverse to the duct axis so that the sectional profile of the duct changes between different stations along the duct axis. The one or more device(s) inhibit the formation of standing acoustic waves in the duct.

Abstract: An aircraft is disclosed having a wing, the wing having a connection interface at the tip of the wing, and the wing being interchangeable between a first configuration in which a first wing tip is connected to the connection interface, and a second configuration in which a second wing tip is connected to the connection interface to replace the first wing tip. The second wing tip comprises a fuel pod for carrying additional fuel, and a wing tip device for improving aerodynamic efficiency. The wing may be designed for performance in both configurations.

Abstract: An aircraft is disclosed having a wing, the wing having a connection interface at the tip of the wing, and the wing being interchangeable between a first configuration in which a first wing tip is connected to the connection interface, and a second configuration in which a second wing tip is connected to the connection interface to replace the first wing tip. The second wing tip comprises a fuel pod for carrying additional fuel, and a wing tip device for improving aerodynamic efficiency. The wing may be designed for performance in both configurations.

Abstract: An aircraft comprising a wing, the wing having a connection interface at the tip of the wing, and the wing being interchangeable between a first configuration in which a first wing tip is connected to the connection interface, and a second configuration in which a second wing tip is connected to the connection interface to replace the first wing tip. The second wing tip comprises a fuel pod for carrying additional fuel, and a wing tip device for improving aerodynamic efficiency. The wing may be designed for performance in both configurations.

Abstract: The present disclosure refers to a method for operating a landing gear system, preferably in a tricycle configuration, wherein main landing gear (MLG) and the nose landing gear (NLG) are operable from a retracted position where they are housed respectively inside landing gear bays, to a fully extended position where they are extended for landing the aircraft. According to the disclosure, the extension of the nose landing gear (NLG) is delayed in time with respect to the extension of the main landing gear (MLG), and the nose landing gear (NLG) is kept retracted during a major part of the time that the main landing gear doors (MLGD) are extended. In this manner, vibrations on the main landing gear doors are reduced and incidents caused by fatigue are also reduced, which in turn implies that the maintenance cost of the aircraft is greatly reduced.

Abstract: An aircraft fuel vent pipe with a pipe body containing a duct which extends along a duct axis between an open end and a closed end. A burst disc closes the closed end of the duct. One or more devices are provided in the duct, the device(s) being positioned or shaped to enable the burst disc to be visually inspected by looking along the duct through its open end, and to modify a sectional profile of the duct transverse to the duct axis so that the sectional profile of the duct changes between different stations along the duct axis. The one or more device(s) inhibit the formation of standing acoustic waves in the duct.

Abstract: An aircraft fuel vent pipe with a pipe body containing a duct which extends along a duct axis between an open end and a closed end. A burst disc closes the closed end of the duct. One or more devices are provided in the duct, the device(s) being positioned or shaped to enable the burst disc to be visually inspected by looking along the duct through its open end, and to modify a sectional profile of the duct transverse to the duct axis so that the sectional profile of the duct changes between different stations along the duct axis. The one or more device(s) inhibit the formation of standing acoustic waves in the duct.

Abstract: An aerodynamic structure comprising a shock bump (3) extending from its surface. The shock bump is asymmetrical about a plane of asymmetry, and the plane of asymmetry: passes through a centre (6) of the shock bump, is parallel with a principal direction of air flow over the structure, and extends at a right angle to the surface of the structure.

Abstract: A morphing aerofoil comprising: a leading edge; a trailing edge; and upper and lower surfaces extending between the leading and trailing edges. An upper thermal actuation member is provided proximate the upper surface; and a lower thermal actuation member is provided proximate the lower surface opposite the upper thermal actuator. The upper and lower thermal actuation members have different thermal expansion coefficients and are positioned such that they cause the trailing edge to deflect when they expand or contract by different amounts in response to a change in ambient temperature, thereby changing a camber of the aerofoil.

Abstract: An aircraft including a wing, the end of the wing having a wing tip device, wherein the wing tip device includes a moveable region that is rotatable, about an axis of rotation extending out of the plane of the wing tip device, between: (i) a high-altitude cruise configuration in which the moveable region extends downwardly below the wing; and (ii) a ground-operating configuration in which the moveable region extends rearwardly behind the wing such that the ground clearance of the wing tip device is increased.

Abstract: The present disclosure refers to a method for operating a landing gear system, preferably in a tricycle configuration, wherein main landing gear (MLG) and the nose landing gear (NLG) are operable from a retracted position where they are housed respectively inside landing gear bays, to a fully extended position where they are extended for landing the aircraft. According to the disclosure, the extension of the nose landing gear (NLG) is delayed in time with respect to the extension of the main landing gear (MLG), and the nose landing gear (NLG) is kept retracted during a major part of the time that the main landing gear doors (MLGD) are extended. In this manner, vibrations on the main landing gear doors are reduced and incidents caused by fatigue are also reduced, which in turn implies that the maintenance cost of the aircraft is greatly reduced.

Abstract: A wing including an airfoil section and having a leading edge, a trailing edge, an upper surface and a lower surface, wherein a region within the airfoil section adjacent the leading edge is ventilated to establish a sub-static pressure in that region during flight. Vents in the upper surface of the wing provide the ventilation.

Abstract: An aerodynamic structure (1) comprising a series of shock bumps (3a, 3b, 3c) extending from its surface. The shock bumps are distributed along a line (7) with a smaller mean angle of sweep than an unperturbed shock (4) which would form adjacent to the surface during transonic movement of the structure in the absence of the shock bumps. Instead of being distributed along the line of the unperturbed shock, the shock bumps are distributed along a line which is less swept than the mean angle of sweep of the unperturbed shock. When the structure is moved at a transonic speed; a shock forms adjacent to its surface and the shock bumps perturb the shock (9) so as to reduce its angle of sweep.

Abstract: An aircraft comprising a wing, the wing having a connection interface at the tip of the wing, and the wing being interchangeable between a first configuration in which a first wing tip is connected to the connection interface, and a second configuration in which a second wing tip is connected to the connection interface to replace the first wing tip. The second wing tip comprises a fuel pod for carrying additional fuel, and a wing tip device for improving aerodynamic efficiency. The wing may be designed for performance in both configurations.

Abstract: An aerodynamic structure comprising a series of shock bumps (3) extending from its surface. The shock bumps are distributed across the structure with a non-uniform spacing (d1, d2) between the centers and/or edges of adjacent bumps. The non-uniform spacing between the bumps can be arranged to give maximum wave drag alleviation for the minimum number of bumps as a function of the shock strength across the span, leading to minimum wing weight penalties for a given amount of wave drag alleviation.

Abstract: An aircraft fuel vent pipe with a pipe body containing a duct which extends along a duct axis between an open end and a closed end. A burst disc closes the closed end of the duct. One or more devices are provided in the duct, the device(s) being positioned or shaped to enable the burst disc to be visually inspected by looking along the duct through its open end, and to modify a sectional profile of the duct transverse to the duct axis so that the sectional profile of the duct changes between different stations along the duct axis. The one or more device(s) inhibit the formation of standing acoustic waves in the duct.