Abstract: An aircraft assembly including a wing component and an engine mounting pylon component. The wing component has three fastening locations arranged in a triangle and a plane. The engine mounting pylon component is connected to the wing component by three tension fasteners, wherein each of the tension fasteners passes through a different one of the fastening locations. The wing component comprises three first spherical surfaces positioned such that the center of each first spherical surface is at a different one of the fastening locations. The engine mounting pylon component comprises three second spherical surfaces having equal and opposite curvature to the first spherical surfaces. Each of the second spherical surfaces is in contact with a different one of the first spherical surfaces.

Abstract: An assembly is disclosed including a first component, a second component, and a spacer component. The first component has a first interface surface. The second component has a second interface surface with a curvature different to the curvature of the first interface surface. The second component is connected to the first component such that the second interface surfaces faces the first interface surface. The spacer component is disposed between the first interface surface and the second interface surface and is configured to be pivotable relative to the first interface surface.

Abstract: A component which is configured to be joined to a further component in a preselected relative orientation is disclosed. The further component has an interface surface and the component is configured to contact the interface surface when joined to the further component. The component includes a surface disposed on a side of the component intended to face the interface surface when the components are joined, a plurality of recesses formed in the surface, and a plurality of spacer elements. Each recess has a preselected orientation relative to the component, the preselected orientation being selected in dependence on the preselected relative orientation. Each spacer element comprises a contact surface configured to contact the interface surface when the components are joined. Each spacer element is disposed in one of the recesses such that the orientation of a given contact surface is defined by the orientation of the corresponding recess.

Abstract: An aircraft assembly is disclosed having a wing and an engine mounting pylon. An aft end of the engine mounting pylon is connected to the wing by a spigot and at least one fastener. The aircraft assembly is configured such that, during operation of the aircraft assembly on an aircraft, the spigot transfers only lateral load between the engine mounting pylon and the wing and the at least one fastener transfers only vertical load between the engine mounting pylon and the wing.

Abstract: An aircraft assembly including: a first aircraft structure, a second aircraft structure, first and second tension bolts arranged to suspend the first aircraft structure below the second aircraft structure, the first and second tension bolts connected to the first aircraft structure such that an end of each of the tension bolts is accessible from respective outer surfaces of the first aircraft structure and first and second fail-safe mechanisms each associated with a respective one of the first and second tension bolts and arranged to suspend the first aircraft structure below the second aircraft structure responsive to failure of the respective tension bolt.

Abstract: An assembly with an aircraft fuel tank is disclosed having a captive nut with an internal thread, a secondary structure, and a fastener which secures the secondary structure to the fuel tank. The fastener has a shaft which passes through the secondary structure and has an external thread coupled to the internal thread of the captive nut. The fuel tank has a fuel tank element with a hole, and the captive nut has a sleeve which is located in the hole with an interference fit between an outer surface of the sleeve and an inner surface of the wall of the hole.

Abstract: A fastener for holding together two or more structures. The fastener includes a first bush and a second bush. The first bush includes a hollow shaft having a first end and a second end opposite to the first end. The first end of the first bush has a first radially-extending protrusion. The second bush includes a hollow shaft having a first end and a second end opposite to the first end. The first end of the second bush has a second radially-extending protrusion. The second end of the second bush is configured to connect to the second end of the first bush so as to resist separation of the first and second bushes and so as to define an axial hole through the fastener defined by the shaft of the first bush and the shaft of the second bush.

Abstract: A barrel nut for a fastener is disclosed. The barrel nut is configured to prevent axial movement of the fastener relative to a structure on which the fastener is installed. The barrel nut comprises a first part and a second part pivotable relative to the first part.

Abstract: An assembly with an aircraft fuel tank is disclosed having a captive nut with an internal thread, a secondary structure, and a fastener which secures the secondary structure to the fuel tank. The fastener has a shaft which passes through the secondary structure and has an external thread coupled to the internal thread of the captive nut. The fuel tank has a fuel tank element with a hole, and the captive nut has a sleeve which is located in the hole with an interference fit between an outer surface of the sleeve and an inner surface of the wall of the hole.

Abstract: A fitting for connecting a first aircraft structure to a second aircraft structure is disclosed including a first substantially planar surface, a second substantially planar surface, a body, and a cavity in the body configured to retain a captive nut. The body connects the first surface to the second surface such that the first surface is at an angle of less than or equal to 90° to the second surface. The cavity is configured such that a captive nut retained therein is adjacent the first surface and the second surface.

Abstract: A joint for connecting a first aircraft structure to a second aircraft structure such that relative rotation and relative translational movement of the first and second aircraft structures along a first axis is permitted, whilst relative translational movement of the first and second aircraft structures along axes orthogonal to the first axis is substantially prevented. The joint includes a bracket having an opening aligned with the first axis; a pin aligned with the first axis and extending through the opening; and a bearing mounted in the opening. The bearing has an inner bearing surface defining a bore through which the pin extends, which is configured for translational sliding contact with the pin, and a part-spherical outer bearing surface configured for rotational sliding contact with the opening.

Abstract: A locking apparatus for locking the rotational position of a fastener component which is rotatable about an axis relative to a structure. The locking apparatus includes a rigid locking member having a first end configured to engage with the fastener component such that rotation of the fastener component relative to the first end is substantially prevented, and a second end configured to engage with the structure such that rotation of the locking member relative to the structure is substantially prevented.

Abstract: A component which is configured to be joined to a further component in a preselected relative orientation is disclosed. The further component has an interface surface and the component is configured to contact the interface surface when joined to the further component. The component includes a surface disposed on a side of the component intended to face the interface surface when the components are joined, a plurality of recesses formed in the surface, and a plurality of spacer elements. Each recess has a preselected orientation relative to the component, the preselected orientation being selected in dependence on the preselected relative orientation. Each spacer element comprises a contact surface configured to contact the interface surface when the components are joined. Each spacer element is disposed in one of the recesses such that the orientation of a given contact surface is defined by the orientation of the corresponding recess.

Abstract: An assembly is disclosed including a first component, a second component, and a spacer component. The first component has a first interface surface. The second component has a second interface surface with a curvature different to the curvature of the first interface surface. The second component is connected to the first component such that the second interface surfaces faces the first interface surface. The spacer component is disposed between the first interface surface and the second interface surface and is configured to be pivotable relative to the first interface surface.

Abstract: A joint for connecting a first aircraft structure to a second aircraft structure such that relative rotation and relative translational movement of the first and second aircraft structures along a first axis is permitted, whilst relative translational movement of the first and second aircraft structures along axes orthogonal to the first axis is substantially prevented. The joint includes a bracket having an opening aligned with the first axis; a pin aligned with the first axis and extending through the opening; and a bearing mounted in the opening. The bearing has an inner bearing surface defining a bore through which the pin extends, which is configured for translational sliding contact with the pin, and a part-spherical outer bearing surface configured for rotational sliding contact with the opening.

Abstract: A barrel nut for a fastener is disclosed. The barrel nut is configured to prevent axial movement of the fastener relative to a structure on which the fastener is installed. The barrel nut comprises a first part and a second part pivotable relative to the first part.

Abstract: A locking apparatus for locking the rotational position of a fastener component which is rotatable about an axis relative to a structure. The locking apparatus includes a rigid locking member having a first end configured to engage with the fastener component such that rotation of the fastener component relative to the first end is substantially prevented, and a second end configured to engage with the structure such that rotation of the locking member relative to the structure is substantially prevented.

Abstract: An assembly with an aircraft fuel tank is disclosed having a captive nut with an internal thread, a secondary structure, and a fastener which secures the secondary structure to the fuel tank. The fastener has a shaft which passes through the secondary structure and has an external thread coupled to the internal thread of the captive nut. The fuel tank has a fuel tank element with a hole, and the captive nut has a sleeve which is located in the hole with an interference fit between an outer surface of the sleeve and an inner surface of the wall of the hole.

Abstract: A fastener for holding together two or more structures. The fastener includes a first bush and a second bush. The first bush includes a hollow shaft having a first end and a second end opposite to the first end. The first end of the first bush has a first radially-extending protrusion. The second bush includes a hollow shaft having a first end and a second end opposite to the first end. The first end of the second bush has a second radially-extending protrusion. The second end of the second bush is configured to connect to the second end of the first bush so as to resist separation of the first and second bushes and so as to define an axial hole through the fastener defined by the shaft of the first bush and the shaft of the second bush.