Abstract: An electrically actuated aircraft brake with a carbon-carbon composite heat pack and an electrical actuator for engaging the heat pack and operating the brake. When the brake is not being applied, the brake actuator is adjusted in dependence upon temperature, for example, by controlling the actuator to maintain a temperature regulated position.

Abstract: Method and apparatus for monitoring electrically-actuated aircraft brakes includes measuring the break heat pack thickness to determine wear of the brake discs and adjusting the measurement so as to give ongoing compensation for temperature variations and hence expansion of the heat pack.

Abstract: An aircraft wheel assembly including an axle housing means for sensing wheel speed, one end of the axle being covered by a cap member (10), the cap member (10) comprising a generally cuplike body (16) having an end wall (14) towards the free end of the axle, the cap including means for driving the wheel speed sensing means, the side wall of the body having at least one stiffening deformation.

Abstract: In the field of avionics, it is difficult to justify initiation of new aircraft programmes for replacement of small numbers of niche aircraft. Instead, in many cases, retrofitting existing aircraft is preferred for economic reasons. In this respect, upgrading existing braking systems to accommodate replacement of existing brake units employing sintered friction materials with brake units employing carbon-carbon composite friction materials is desirable. However, when upgrading the braking systems it is necessary to ensure that the integrity of the existing airframe is not compromised by the use of the new brake assemblies employing the carbon-carbon composite friction materials. Consequently, the present invention replaces existing pressure control valves of existing braking systems with an electronic control unit coupled to a pressure control servovalve, thereby ensuring proper application of hydraulic pressure to brake assemblies.

Abstract: A system and method for monitoring the applications of carbon-carbon brakes of an aircraft to determine brake condition and operate a brake maintenance program or charge a brake system user. The system and method includes monitoring each actuation of the brakes and making a separate record of each actuation of the brakes in which there is relative movement of the facing friction surfaces that cause wear, and from that separate record determining brake usage. The monitoring may include measuring changes and processing the signals to distinguish between those which fall below and those which are above a threshold value. The method and system may comprise sensing a plurality of braking parameters having values dependent upon the wear in the system and different faults of the system, and identifying and recording wear and faults based on combinations of values of the parameters.

Abstract: Refractory carbide particles are located in a defined area of a matrix, specifically silicon carbide particles are encapsulated within a porous matrix or carbon precursor, by locating particles of refractory carbide-forming material or a precursor thereof in a defined area of the matrix followed by depositing carbon within the matrix at a temperature below that of the melting point of the carbide-forming material.

Abstract: A system and method for monitoring the usage of brake members of an aircraft braking system. The system makes a separate record of each brake actuation in which there is relative movement of the brake member's facing friction surfaces which causes wear, determines the types of brake usage and operates a pricing/payment scheme to charge for brake usage.

Abstract: System and method for monitoring the applications of the brakes, e.g. of an aircraft to determine brake condition and operate a brake maintenance programme or charge a brake system user. It is desirable to have accurate information for determining the condition and predicting the life of carbon-carbon brake discs. This is important for safety as well as commercial reasons. The number of landings of an aircraft is often used as a determinant for such as lifetime warranties for brake discs and recommended maintenance periods. However, at least for carbon disc brakes, this may not be entirely accurate. For example such brake discs also wear during taxiing. The system and method herein includes monitoring each actuation of the brakes and making a separate record of each actuation of the brakes in which there is relative movement of the facing friction surfaces that cause wear, and from that separate record determining brake usage.

Abstract: A valve body comprises two inlet ports for receiving fluid at respective different pressures, an outlet port for delivering said fluid, a valve member mounted for limited movement within said body, and biasing means for biasing said valve member to move to one limit of its movement, said valve member being operable to move in response to the difference in pressure at said first and second ports in response to said biasing means for causing the valve member to vary the respective contributions of fluid delivered to the outlet port from the inlet ports. The valve body can contain a further movable valve member which is operable for receiving fluid from isolating control means and, in response thereto, for moving to obstructions one of said inlet ports and for urging the first mentioned valve member to obstruct the other inlet port.

Abstract: An aircraft brake assembly incorporating components which are sensitive to heat and to contact with substances present in runway,.e.g., de-icer compositions and cleansing liquids. The assembly includes an external member to shield the components from the liquids. The external member may comprise a rigid or flexible, fluid-impermeable or porous material located to receive and retain the liquids. Heat generated through the use of the brake assembly may evaporate any liquid settled on the external member or at least discourage any liquid from settling thereon.

Abstract: Apparatus for the release of pressurised fluids comprising an opening through which pressurised fluids may pass and an attenuator member extending over said opening. The attenuator member operates to control the flow of said fluid and attenuate sound associated therewith.

Abstract: A composite article for use in an aircraft brake heat pack, the article comprises a core layer having a face portion and a wear layer attached to the face portion, wherein the wear layer has a density lower than the core layer. The core layer is preferably formed from impregnated C—C and the wear layer is preferably formed from C—C. The article may be used as a brake disc.

Abstract: An annular body, and method of making same, comprising at least one wear surface portion, the portion comprising a plurality of layers held in a matrix, each layer consisting essentially of fibres which extend generally in one direction and parallel to each other and from the centre of the body to the periphery, whereby the wear of that surface portion is improved. The body can be formed into an aircraft brake disc.

Abstract: Refractory carbide particles are located in a defined area of a matrix, specifically silicon carbide particles are encapsulated within a porous matrix or carbon precursor, by locating particles of refractory carbide-forming material or a precursor thereof in a defined area of the matrix followed by depositing carbon within the matrix at a temperature below that of the melting point of the carbide-forming material.

Abstract: A porous preform body is infiltrated with carbon by a thermal gradient process using a multi-portion heating element to heat the body. Selected portions of the heating element are supplied with power to create the thermal gradient between different areas of the preform body.

Abstract: In a braking system including a plurality of independently operable hydraulic brake assemblies, a controller is provided for monitoring the hydraulic pressure at at least some of the brake assemblies and for comparing that pressure with a brake control demand signal so that all or substantially all brake assemblies can be brought into operation if that comparison indicates a requirement for additional or full braking operation.

Abstract: A method of depositing a carbon-containing substance in the pores of a porous body comprises establishing an open varying magnetic field flux loop and placing the body such that a magnetic field flux generated by the open magnetic field flux loop passes through a region of said body and heats that region, creating a thermal gradient across the body and bringing a thermally decomposable carbon-containing gas into contact with the heated region, thereby depositing a carbon-containing substance in the pores of said heated region.