Abstract: A single acting actuator for an aircraft landing gear assembly is disclosed having a piston mounted in a cavity and moveable relative to a housing between a retracted position and an extended position, the piston dividing the cavity into first and second pressure chambers. At least one of the pressure chambers is associated with first and second outlets, with the actuator being arranged such that, in respect of the relative movement in which the pressure chamber is the decreasing volume pressure chamber, in a first stage of the relative movement the first and second outlets are open thereby allowing actuator fluid to flow out of the pressure chamber through the first and second outlets and in a second stage of the relative movement the second outlet is open but the first outlet is closed, thereby acting to slow the relative movement of the piston with respect to the housing.

Abstract: A braking system and a method for applying one or more aircraft wheel brakes according to at least one of a plurality of wheel brake control functions are disclosed. The method includes receiving an indication of an aircraft speed from an aircraft speed indicator, controlling a wheel braking operation of the aircraft according to at least a first wheel brake control function if the aircraft speed indicated by the aircraft speed indicator exceeds a speed threshold, and controlling the wheel braking operation of the aircraft according to at least a second wheel brake control function if the aircraft speed does not exceed the speed threshold. Also disclosed is an aircraft including one or more aircraft wheel brakes and the disclosed braking system.

Abstract: A method of testing a system model is disclosed. The system model includes a system parameter and three or more equipment models, each equipment model includes an equipment parameter which models a parameter of a respective equipment. The method includes (a) making a series of changes of the equipment parameter of one of the equipment models so that the equipment parameter of the one of the equipment models adopts a series of test values of the equipment parameter; (b) operating the system model to determine a series of test values of the system parameter, each test value of the system parameter is determined in accordance with a respective one of the test values of the equipment parameter; (c) determining a weight of the selected one of the equipment models, the weight of the one of the equipment models indicates a sensitivity of the system parameter to the series of changes in the equipment parameter of the one of the equipment models; and (d) outputting the weight of the one of the equipment models.

Abstract: An apparatus for monitoring a tire and/or a wheel including a sensor system; a wireless communication interface; a processor connected to the sensor system and the wireless communication interface; a power source; and a mounting system for attaching the apparatus to a wheel. The mounting system is configured to allow movement of the sensor system relative to the wheel in use.

Abstract: An apparatus and method for installing an aircraft bulkhead connector with a bulkhead is disclosed where access to only one side of the bulkhead is required. The disclosure is also applicable to installation of bulkhead connectors in aircraft fuel tanks. An aircraft bulkhead connector and installation tool is also disclosed. The bulkhead connector includes a female end portion and the installation tool includes a male end portion. The male end portion of the installation tool is removably engaged with the female end portion of the bulkhead connector, such that the installation tool protrudes beyond the female end portion of the bulkhead connector. The installation tool may be inserted through an aperture in a bulkhead and used to both position and hold the bulkhead connector during the installation process.

Abstract: A system 100 to detect aircraft ground proximity including: a transmitter 110 for transmitting a radio frequency signal along an extended landing gear 20 of an aircraft 10, a sensor 120 configured to detect a parameter of the radio frequency, and a controller 130 configured to detect a change in the detected parameter on the basis of an output of the sensor 120, and to issue a landing signal when the change in the detected parameter meets a predetermined criterion. The predetermined criterion is indicative of a certain aircraft ground proximity.

Abstract: A structure formed from composite material and method of forming a composite structure is disclosed in which one or more metal layers are disposed on a composite structural member.

Abstract: An aircraft landing gear is disclosed having a landing gear leg attachable at a first end to an aircraft, and an axle beam, both the landing gear leg and the axle beam being rotatably mounted. The axle beam is rotatable between a first position, in which a first end of the axle beam is a first (shorter) distance from the first end of the landing gear leg, and a second position, in which said first end of the axle beam is a second (longer) distance from the first end of the landing gear leg. A biasing member is configured to be able to bias the axle beam towards the second position. An aircraft, a blended wing body aircraft, and a method of operating an aircraft are also disclosed.

Abstract: A duct stringer forms at least part of a duct with a closed cross-section which is adapted to transport fluid. The duct stringer has a duct wall and a female bayonet fitting in the duct wall. The female bayonet fitting is configured to engage with a male bayonet fitting on a fluid transporting conduit to connect the fluid transporting conduit with the duct.

Abstract: A spoiler for an aircraft wing is movable between a stowed configuration and a deployed configuration in a “pop-up” manner. The spoiler includes a hinged top flap movable between a first position and a second position, wherein in the first position the hinged top flap is constrained by an actuator, and in the second position the hinged top flap is unconstrained by the actuator. When the hinged top flap is in the second position, airflow over the top surface of the aircraft wing acts to pull the spoiler into the deployed position.

Abstract: An aircraft wing is disclosed including a closed surface wing tip device which includes an element or actuator within the wing tip for deforming/morphing the shape of the wing tip between geometrical configurations having different aerodynamic properties, for example including one with better overall fuel efficiency for a shorter journey and one with overall fuel efficiency better suited for a longer journey. The device includes a lower winglet with an essentially planar portion spaced apart from the main body of the wing by a blended transition region which is shaped such that the curvature of the local dihedral increases in the outboard direction. The device includes an upper aerofoil structure which with the winglet essentially forms the closed surface. There is also disclosed an aircraft wing tip device having a sigmoid shaped (e.g. S-shaped) aerofoil structure blending in with a main wing of the aircraft.

Abstract: A method of monitoring the pressure of a tire of an aircraft is disclosed including taking two or more pressure readings from the tire at different times; calculating an estimated deflation rate based on the pressure readings; and calculating a time for the tire to deflate to a reference pressure level based on the estimated deflation rate. Two or more temperature readings are each associated with one of the pressure readings, and the estimated deflation rate is calculated by normalising each pressure reading based on its associated temperature reading and a common reference temperature to obtain a temperature-normalised pressure reading, and calculating the estimated deflation rate based on the temperature-normalised pressure readings. The estimated deflation rate is compared with a threshold, and a warning provided if the estimated deflation rate exceeds the threshold.

Abstract: An airfoil structure for an aircraft includes a spanwise-extending load-carrying member, a leading-edge structure, a trailing-edge structure, an upper cover, and a lower cover. The load-carrying member is configured to react more than half of all flight loads experienced by the airfoil structure during flight and is configured to have selected stiffness properties selected such that the airfoil structure bends and twists in a predefined manner in response to applied flight loads. The leading-edge structure is configured to form a leading-edge part of an aerodynamic surface of the airfoil structure. The trailing-edge structure is configured to form a trailing edge part of the aerodynamic surface. The upper cover is configured to form an upper part of the aerodynamic surface. The lower cover is configured to form a lower part of the aerodynamic surface.

Abstract: An aircraft engine nacelle for coupling to a wing of an aircraft is disclosed having a fore end, and an aft end that is immoveable relative to the fore end. The aft end includes a major axis Mj and a minor axis Mi, and the nacelle is configured such the minor axis Mi is closer to vertical V than the major axis Mj when the nacelle is coupled to the wing and the aircraft is stationary on the ground. An aircraft system and an aircraft are disclosed each including the aircraft engine nacelle.

Abstract: An aircraft wing including a fixed wing and a wing tip device rotatable about a hinge at the tip of the fixed wing is disclosed. The wing further includes a hinged panel at the boundary between the wing tip device and the fixed wing. In the flight configuration the panel is closed such that the panel is substantially flush with the upper surface of the wing, and the hinged panel is located in the path of a moveable element (for example part of an actuation mechanism, such as a curved rack). In the ground configuration the panel is hinged open to a position outside the path of the moveable element such that clashing of the moveable element with the stationary structure at the tip of the fixed wing is avoided.

Abstract: An aircraft wing with a wing structure and a spoiler movable between a stowed configuration and a deployed configuration are disclosed. The spoiler includes an actuator configurable between an engaged mode and a disengaged mode. When the actuator is in the engaged mode, the actuator can restrict movement of the spoiler and move the spoiler between the stowed configuration and deployed configuration. In the disengaged mode, the actuator allows free movement of the spoiler, such that the spoiler may pop up due to reduced air pressure on the aircraft wing.

Abstract: A routine maintenance procedure performed in respect of a wheel of an aircraft landing gear is disclosed. Consumable brake lining material is integrated with the wheel. Re-treading or replacing the wheel tyre and inspecting or replacing the consumable brake lining material tyre are performed at the same successive intervals as part of the routine maintenance procedure. The sum volume and mass of brake material present on the aircraft may thus be reduced. Brake material providing for the demands of a maximum energy rejected take-off may be provided separately. The wheel may be made in one or two parts from carbon-fibre composite material. At least some of the brake material may be provided on an outwardly facing planar surface of the wheel.

Abstract: A sensor network for use in an aircraft, including a plurality of wireless nodes. A first wireless node of the plurality of wireless nodes is arranged to communicate with at least one other wireless node of the plurality of wireless nodes. The communication is via a secure communications channel and is on the basis of a control message received at the first wireless node. The at least one other wireless node is arranged to perform an operation on the basis of the control message.

Abstract: A landing gear controller (120) to control extension and retraction of a landing gear for an aircraft, the landing gear controller (120) configured to cause, during an aircraft take-off or landing procedure, a landing gear extension and retraction system (110) to perform only a first portion of a landing gear extension or retraction process, on the basis of a status of the aircraft and prior to receiving a command for the landing gear to be extended or retracted.

Abstract: An aircraft wing box is disclosed having a first cover, a second cover, a partition extending between the first and second cover and configured to provide a fuel tight boundary between the first and second covers, a first joint coupling the partition to the first cover, and a second joint coupling the partition to the second cover. The first joint is a slip joint configured to inhibit fuel leakage across the slip joint whilst permitting relative movement between the partition and the first cover.