Abstract: A method, system, and computer program product for bit flip aware latch placement in integrated circuit generation are provided. The method identifies a chip design for an integrated circuit. A set of chip design constraints, associated with the chip design, is identified. A set of checking groups, associated with a plurality of latches to be placed in the chip design, is determined. Based on the set of chip design constraints and the set of checking groups, a placement scheme for the plurality of latches is selected. The method places the plurality of latches within the chip design based on the placement scheme and the set of checking groups.

Abstract: Embodiments for power generation include defining a power tile within a power distribution network having a grid of power rails, the power tile having logic gates, and applying an initial power grid pattern from a plurality of power grid patterns for the power tile such that initial power grid pattern relates to timing characteristics of the logic gates of the power tile. The power grid patterns each have a different number of connectors connecting one power rail to another power rail in the grid of power rails. A subsequent power grid pattern is selected from the power grid patterns for the power tile such that the subsequent power grid pattern meets a threshold condition for the timing characteristics of the logic gates of the power tile. The timing characteristics for the logic gates are determined based on a voltage drop associated with the subsequent power grid pattern.

Abstract: A passive filter for connection between an AC source and a load, in either three-phases or in a single-phase arrangement. The filter includes, for each phase, a trap circuit having an inductor in series with a capacitor, the trap circuit having at least two terminals. A line reactor is connected between the AC source and the load, the line reactor having at least an input terminal, an output terminal and a tap terminal. A switch selectively connects at least one of the trap circuit terminals to a selected one of the line reactor terminals. The switch is capable of selecting which of the trap circuit terminals to connect to which of the line reactor terminals on the basis of a level of voltage distortion being experienced by the AC source, or on the basis of a calculated level of background voltage total harmonic distortion.

Abstract: An aircraft landing gear assembly comprises a landing gear (10) arranged to be moveable between a stowed position and a deployed position. The assembly includes a removably mounted cover plate (20) that covers a void (12) defined by a part of the landing gear assembly. The plate (20) may have a substantially constant thickness, one or more fixing elements (22) on one side only of the plate, and a sealing element (34) that extends around substantially the entire perimeter (20a) of the plate (20).

Abstract: A passive filter for connection between an AC source and a load, in either three-phases or in a single-phase arrangement. The filter includes, for each phase, a trap circuit having an inductor in series with a capacitor, the trap circuit having at least two terminals. A line reactor is connected between the AC source and the load, the line reactor having at least an input terminal, an output terminal and a tap terminal. A switch selectively connects at least one of the trap circuit terminals to a selected one of the line reactor terminals. The switch is capable of selecting which of the trap circuit terminals to connect to which of the line reactor terminals on the basis of a level of voltage distortion being experienced by the AC source, or on the basis of a calculated level of background voltage total harmonic distortion.

Abstract: An aircraft landing gear (9) includes a wheel (1) having a wheel rim (3) on which a tire (4) is held. The gap (6) between the rim (3) and tire (4) is bridged and covered by a sealing element (7), which thereby presents a smooth surface to the air flowing over the wheel during flight of the aircraft (8). Thus, noise that would otherwise be generated by the interaction of air and the parts of the wheel (1) and/or tire (4) defining the gap (6) is reduced. Such noise reduction benefits may also be achieved by providing a tire (4) and wheel (1) so shaped that there is no gap (6) between the tire (4) and wheel rim (3).

Abstract: An aircraft landing gear is arranged such that in its deployed position it is configured to reduce, during the approach on landing, the noise generated by the interaction of the landing gear and the air flowing past the landing gear. Various means are described to reduce the amount of turbulent air flow generated in the region of the landing gear, including inverting and fairing the nose-gear shock-absorbing leg, providing faired twin in-line oleos and providing fairings that produce shielding air curtains.

Abstract: An aircraft landing gear is arranged such that in its deployed position it is configured to reduce, during the approach on landing, the noise generated by the interaction of the landing gear and the air flowing past the landing gear. Various means are described to reduce the amount of turbulent air flow generated in the region of the landing gear, including inverting and fairing the nose-gear shock-absorbing leg, providing faired twin in-line oleos and providing fairings that produce shielding air curtains.

Abstract: The invention provides a landing gear 120 for an aircraft 110, the landing gear comprising a main strut 121 having a first upper end arranged to be moveably mounted to a structure of the aircraft, a landing gear wheel assembly 131, 132 connected to a second lower end of the main strut, the landing gear wheel assembly comprising at least one landing gear wheel arranged to roll in a fore-aft direction with respect to the main strut, and a stay 122 having a first upper end arranged to be connected to a structure of the aircraft, and a second lower end pivotally mounted to a mounting element 140 on the main strut, wherein the mounting element on the main strut is positioned substantially in line with the main strut in the fore-aft direction. The invention also provides a main strut, an aircraft and a kit of parts.

Abstract: An aircraft landing gear is described including a noise-reducing means. In one embodiment there is a noise-reducing element that includes an air-deflecting surface, in the form of a fairing, and a perforated airflow-reducing region. In use, some air passes through the perforations, while other air is deflected by the fairing away from a noise-generating region of the landing gear. Noise caused by the passing of the landing gear through the air is therefore reduced. In another embodiment a noise-reducing layer in the form of a mesh is supported by a skeleton structure.

Abstract: An aircraft landing gear (10) includes a torque link set (12) comprising a first fairing (12a) rotatably connected at a first end (18) to a first end (19) of a second fairing (12b). The fairings (12a), (12b) may be arranged to act as first and second torque links. The fairings may be in the form of noise reduction fairings.

Abstract: The invention relates to aircraft noise reduction apparatus, in particular, but not exclusively, to noise reduction apparatus on an aircraft landing gear. The aircraft noise reduction apparatus comprises a noise reduction attachment for a landing gear of an aircraft. The noise reduction apparatus is movable between a first position in which it deflects air away from a noise inducing component of the landing gear and a second position in which it allows access to the noise inducing component. The movement of the noise reduction attachment between the first and second positions is actuated by a part of the landing gear.

Abstract: An aircraft landing gear 501 includes a folding side stay 502, wherein the folding side stay includes an integral locking mechanism and does not require the landing gear to include a lock stay. The lack of a lock stay reduces the airframe noise created by the aircraft, which is particularly significant when the aircraft is landing. The aircraft landing gear 501 is movable between an stowed and deployed position. The folding side stay 502 comprises a first section and a second section foldable relative to the first section. The integral locking mechanism 503 is arranged to lock the first section and second section of the folding side stay into position when the landing gear is in the deployed position.

Abstract: An aircraft landing gear door assembly includes a door, which is moveable to an open position, in which an aperture is exposed, the landing gear being able to be deployed through said aperture, and moveable to a closed position, in which the door is closed across the aperture. The door is arranged for rotational movement of a first type, in which the door rotates about an axis that is substantially parallel to the length of the aircraft, between the closed position and the open position. The door is also arranged for movement of a second type, different from the first type, in which the door rotates, about an axis that is substantially transverse to the length of the aircraft, to a position in which it acts as a fairing to reduce the noise caused by the landing gear or a part thereof. In one embodiment, the second type of movement is rotational movement about an axis that is substantially parallel to the door when in the closed position and the door forms a ramp type fairing.

Abstract: A current mode logic voter circuit includes three two-input split NOR gates. Each two-input split NOR gate receives a corresponding pair of input signals and generates a pair of first output signals responsive to the input signals. A three input split NOR gate is coupled to the two-input split NOR gates to receive the first output signals and generates a second pair of output signals responsive to the first output signals from the two-input split NOR gates. The two and three-input split NOR gates can be formed from current mode logic buffer circuits, and in one embodiment in the three-input split NOR gate the buffer circuits are hardened.

Abstract: An aircraft landing gear assembly comprises a landing gear (10) arranged to be moveable between a stowed position and a deployed position. The assembly includes a removably mounted cover plate (20) that covers a void (12) defined by a part of the landing gear assembly. The plate (20) may have a substantially constant thickness, one or more fixing elements (22) on one side only of the plate, and a sealing element (34) that extends around substantially the entire perimeter (20a) of the plate (20).

Abstract: An aircraft landing gear is arranged such that in its deployed position it is configured to reduce, during the approach on landing, the noise generated by the interaction of the landing gear and the air flowing past the landing gear. Various means are described to reduce the amount of turbulent air flow generated in the region of the landing gear, including inverting and fairing the nose-gear shock-absorbing leg, providing faired twin in-line oleos and providing fairings that produce shielding air curtains.

Abstract: A current mode logic voter circuit includes three two-input split NOR gates. Each two-input split NOR gate receives a corresponding pair of input signals and generates a pair of first output signals responsive to the input signals. A three input split NOR gate is coupled to the two-input split NOR gates to receive the first output signals and generates a second pair of output signals responsive to the first output signals from the two-input split NOR gates. The two and three-input split NOR gates can be formed from current mode logic buffer circuits, and in one embodiment in the three-input split NOR gate the buffer circuits are hardened.

Abstract: An aircraft landing gear (10) includes a torque link set (12) comprising a first fairing (12a) rotatably connected at a first end (18) to a first end (19) of a second fairing (12b). The fairings (12a), (12b) may be arranged to act as first and second torque links. The fairings may be in the form of noise reduction fairings.

Abstract: An aircraft noise reduction apparatus including an aircraft landing gear assembly (10) and a noise reduction fairing (12) is described. The landing gear assembly comprises (10) a landing gear bay having an aperture (14), a landing gear moveable between a stowed position and a fully deployed position, and at least one landing gear bay door (16) moveable to close and open the aperture. The noise reduction fairing (12) is positioned fore of the landing gear bay door assembly. The noise reduction fairing (12) is moveable between a stowed position and a fully deployed position such that in the fully deployed position, the noise reduction fairing (12) acts to reduce noise that would otherwise be generated by the interaction of the landing gear assembly when deployed and the air flowing past it.