Abstract: A system and method for fabricating a composite material assembly. The components of the assembly originate from more than one mold while providing curing or solidifying under heat and vacuum in one step only, preferably with a composite material in a pre-preg form which does not require autoclave treatment. A removable insert is removed from a second mold prior to assembly of a first mold to the second mold. A section of a laminate extending over the removable insert overlaps over an adjacent laminate after closing and assembly of the first mold onto the second mold.

Abstract: A grommet (10) for use with the face or web of a component such as sheet material for protecting the surface of articles passing through apertures formed in said component, said grommet comprising a generally cylindrical main wall portion (12) having adjacent one axial end thereof an outwardly extending lip portion(14), said main wall portion including a plurality of axially directed resilient fingers (24), at least some of said fingers having means (26) for resisting disengagement of said grommet from said component.

Abstract: A power unit for providing propulsive thrust includes an efflux duct defining a first fluid flow path along which gaseous fluid travels for discharge from a first fluid exit opening to provide propulsive thrust. The power unit also has a thrust reversing structure which, when in a deployed position, redirects the flow of gaseous fluid along a second fluid flow path to discharge from a second fluid exit opening to provide reverse thrust. The thrust reversing structure includes longitudinally translating cowl portions, which are moveable from a stowed position to the deployed position where the translating cowl portions block a major portion of the first fluid exit opening to cause gaseous fluid to efflux from the second fluid exit opening. The translating cowl portions move in a generally longitudinal direction towards the deployed position along a path which is inclined to the power unit axis.

Abstract: A missile in which a nose portion is rotatably mounted on a main body portion of the missile and is subjected to thrust to bring it to a demanded roll attitude and to apply to it a demanded lateral steering force. The thrust is produced by a propellant gas and supplied to discharge ducts in the nose portion which provide for the discharge of the propellant gas tangentially with respect to the nose portion. The discharge ducts are selectively opened and closed by relative axial displacement of the nose portion and a valve spool which controls the flow of propellant gas. An actuator responsive to guidance control signals causes a predetermined roll torque to bring the nose portion to a demanded roll attitude and a predetermined lateral steering force on the missile.

Abstract: An apparatus and method for forming a fiber reinforced resin composite component by a resin transfer infusion (RTI) process in which a preform is laid up on a hard base tool and a bagging blanket is applied as a flexible upper tooling. Edge and/or other regions of the preform are superimposed by localized control plates which, together with spacer pins passing through the preform, serve to determine localized dimensional accuracy in the component without the need for hard upper tooling throughout.

Abstract: An anodic oxide film is formed on an aluminium or aluminium alloy work piece by forming an anodic oxide film on the work piece by AC electrolysis followed by subjecting the work piece to DC electrolysis. The AC anodizing step may be conducted at a voltage of 5 to 30V for 30 seconds to 10 minutes and the DC anodizing step may be conducted at a voltage of 5 to 30V for a period of 1 to 20 minutes. The anodic oxide coating is suitable for adhesive bonding of aluminium alloy work pieces.

Abstract: A method and apparatus for forming a fibre reinforced composite structure comprising at least two components, a hard base tool presenting a first tool face, a second tooling element presenting a second tool face to locate the second component against the first component. Components are of a dry fibrous form and are to be injected with a liquid resin. A flexible bagging blanket forms with the tools a sealed enclosure into which the resin is injected to form the structure by resin transfer infusion. To maintain the relative dispositions of the components without the need for elaborate mandrel plates, control rods are inserted at least partially through the two components to act as fasteners and to maintain the relative disposition of the components during resin injection. After injection the assembly is cured and the control rods may remain in situ or be removed from the structure.

Abstract: A beam-riding missile (10) has a freely rotating control portion (11) forming its nose and carrying a pair of fixed ailerons (13) and a pair of fixed elevators (14). Detecting means (not shown) gather information indicative of the location of the missile in the beam and steering logic circuitry (not shown) provides signals to a clutch (18) which interfers with the free rotation of the nose in such a way that the elevators are effective to maintain the chosen flight path. The clutch can be electromagnetic, piezo-electric or function on the Johnson-Raebeck effect. The combination of fixed control surfaces and steering by a single actuator leads to the possibility of useful reductions in the size, weight and complexity of the missile.

Abstract: A power unit for providing propulsive thrust includes an efflux duct defining a first fluid flow path along which gaseous fluid travels for discharge from a first fluid exit opening to provide propulsive thrust. The power unit also has a thrust reversing structure which, when in a deployed position, redirects the flow of gaseous fluid along a second fluid flow path to discharge from a second fluid exit opening to provide reverse thrust. The thrust reversing structure includes longitudinally translating cowl portions, which are moveable from a stowed position to the deployed position where the translating cowl portions block a major portion of the first fluid exit opening to cause gaseous fluid to efflux from the second fluid exit opening. The translating cowl portions move in a generally longitudinal direction towards the deployed position along a path which is inclined to the power unit axis.

Abstract: An anodic oxide film is formed on an aluminium or aluminium alloy work piece by forming an anodic oxide film on the work piece by AC electrolysis followed by subjecting the work piece to DC electrolysis. The AC anodizing step may be conducted at a voltage of 5 to 30V for 30 seconds to 10 minutes and the DC anodizing step may be conducted at a voltage of 5 to 30V for a period of 1 to 20 minutes. The anodic oxide coating is suitable for adhesive bonding of aluminium alloy work pieces.

Abstract: An aircraft structure includes a duct having an inlet for fluid flow into the duct and a first outlet for fluid flow out of the duct. The duct is configured to guide fluid flow out of the duct through the first outlet in an at least partially reversed direction relative to fluid flow into the duct to thereby reverse thrust.

Abstract: An aircraft having a propulsive power unit supported in a fuselage mounted configuration and including an engine and a nacelle structure housing the engine. The nacelle structure is provided with upper and lower displaceable nacelle portions, such as thrust reverser cowls and fan cowl doors which are displaceable between closed dispositions which they occupy during operational conditions of the aircraft and open dispositions which they take up to provide access to engine components. The upper and lower nacelle portions are so mounted as to be displaceable to their open and closed dispositions in movements in which one is assisted by gravitational force and the other is displaced against gravitational force. A force transfer mechanism is provided for transfer during opening and closing movements of the nacelle portions of gravitational force assisting displacement of one of the nacelle portions to assist in displacement of the other nacelle portion being displaced against gravitational force.

Abstract: An aircraft engine nacelle nose cowl has a supply duct to deliver pressurised hot gas into an internal compartment of the nose cowl. A slot is provided in the nose cowl to enable pressurised hot gas to pass out of the compartment through the slot. As the pressurised hot gas passes out of the compartment through the slot, this causes a film of water on an outer surface of the nose cowl to detach from the nose cowl. The slot is of restricted dimensions which causes localised heating of the nose cowl around the slot as the pressurised hot gas pass out of the compartment through the slot. In this manner ice is prevented from accumulating on the outer surface of the nose cowl and/or ice is removed from the outer surface of the nose cowl.

Abstract: A missile system and a method of missile guidance in which a bus missile is launched from a launch station remote from a target with the bus missile carrying a plurality of sub-missiles. The sub-missiles are then launched from the bus missile during flight of the bus missile. The sub-missiles are arranged to deploy ahead of the bus missile and are guided to the target under the control of a guidance beam generated in and transmitted from the bus missile.

Abstract: A noise attenuation panel used to attenuate noise in aircraft engines includes a cellular core and a facing sheet formed with an array of holes. The holes are laser drilled to provide: (i) hole size variation over the facing sheet; (ii) non-circular hole cross section; (iii) polygonal hole cross section; (iv) hole locations not contiguous with walls of the cellular core; and (v) inclined holes passing through the facing sheet in a direction inclined to the normal to the facing sheet.

Abstract: A thrust reversing arrangement for an aircraft turbofan propulsive power unit includes a flow redirecting structure which has reverse flow enhancing sub-structures comprising: (i) a cavity which is so dimensioned as to generate a back pressure which supports redirection of flow; (ii) a cascade assembly which provides a flow control slot so dimensioned as to optimize reverse thrust for predetermined fan duct flow conditions; (iii) an obstructing duct wall portion having a leading edge so positioned as to form a leakage slot providing controlled leakage of forward flow; (iv) a box structure, the dimensions of which are such as to optimize back pressure in the cavity; and (v) provision for gaseous fluid under static pressure from the fan duct to load the redirecting structure to the inoperative position.

Abstract: A noise attenuation panel used to attenuate noise in aircraft engines includes a cellular core and a facing sheet formed with an array of holes. The holes are laser drilled to provide: (i) hole size variation over the facing sheet; (ii) non-circular hole cross section; (iii) polygonal hole cross section; (iv) hole locations not contiguous with walls of the cellular core; and (v) inclined holes passing through the facing sheet in a direction inclined to the normal to the facing sheet.

Abstract: A noise attenuation panel used to attenuate noise in aircraft engines includes a cellular core and a facing sheet formed with an array of holes. The holes are laser drilled to provide: (i) hole size variation over the facing sheet; (ii) non-circular hole cross section; (iii) polygonal hole cross section; (iv) hole locations not contiguous with walls of the cellular core; and (v) inclined holes passing through the facing sheet in a direction inclined to the normal to the facing sheet.

Abstract: In the manufacture of a noise attenuation panel for an aeroengine nacelle an adhesive film is applied to a front face of a cellular component of the panel. The adhesive film is caused to reticulate to the ends of the walls of the cells at the front face of the cellular component. A perforate facing component of the panel is bonded to the front face of the cellular component by adhesive flow from the cell walls to the facing component. To avoid unpredictable adhesive flow giving rise to cosmetic spots on the front face of the facing component the two components are brought together with the interposition of an adhesive flow control sheet and the reticulated adhesive caused to bond the two components together by adhesive flow under the control of the adhesive flow control sheet.

Abstract: A noise attenuation panel used to attenuate noise in aircraft engines includes a cellular core and a facing sheet formed with an array of holes. The holes are laser drilled to provide: (i) hole size variation over the facing sheet; (ii) non-circular hole cross section; (iii) polygonal hole cross section; (iv) hole locations not contiguous with walls of the cellular core; and (v) inclined holes passing through the facing sheet in a direction inclined to the normal to the facing sheet.