Abstract: An apparatus and method for reducing noise within the fuselage of a propeller driven aircraft. In one embodiment the propeller blades are spaced apart and in front of an offset inlet. The inlet provides air to a gas turbine engine powering the propeller, and also to a scavenge duct. The propeller blades and inlet are spaced apart such that during cruise conditions for the aircraft, the trailing edge of the propeller blades are spaced apart from the inlet by more than one-fourth of the chord length of the propeller blades, and less than about the chord length of the propeller blades. This spacing reduces the aerodynamic interaction between the propeller blades and a bubble of partially stagnated air in front of the inlet. In another embodiment, the scavenge duct is constructed such that it flows an increased amount of air, thus allowing the inlet duct to flow an increased amount of air.

Abstract: A printed circuit assembly (5) has a surface mount electronic component (14), circuit board (10), and locating features to align (16) the surface mount electronic component on the printed circuit board. The locating features may comprise solder bumps (24) on the printed circuit board. The locating features are arranged on the surface of the printed circuit board to lie proximal to the main body (22) of the surface mount electronic component. The locating features prevent movement of the surface mount electronic component prior to soldering the surface mount electronic component to the printed circuit board.

Abstract: An electronic circuit assembly (100) includes a circuit carrying substrate (150) on which electrical components (130) are mounted using solder deposits (125) having an essentially planar surface. A solder deposit (125) is created by forming a recess (155) in the substrate (150), providing a metallic pad (110) about the recess (155), depositing solder paste (120) on the metallic pad (110), and reflowing the solder paste (120) on the metallic pad (110). The electronic circuit (100) is assembled by placing electrical components (130) on the substrate (150) having solder deposits (125), and by further reflowing the solder deposits (125) on the metallic pad (110).

Abstract: A solder joint inspection system comprises a substrate (60) having at least one solder pad (56), a predetermined amount of solder (54) on the solder pad, and an image fluxing material (52) that fluoresces when an ultraviolet light source (42) is applied to the solder (54) and the fluxing material (52). When an ultraviolet light source is applied to the substrate having a predetermined amount of solder and fluxing material, a visual inspecting device (40) can verify if, in fact, the predetermined amount of solder and fluxing material is present.

Abstract: Fabrication of a high precision mirror using a discontinuous metal matrix mposite is described. A metal matrix composite (MMC) is obtained by using one of the three methods described herein or any other method. The MMC material so obtained is machined to form a mirror substrate which is then coated and the coating so obtained is converted into the mirror surface. The mirror so obtained has better characteristics over the conventional high precision beryllium mirrors used for this purpose and is fabricated out of a nontoxic material which is cheaper and more easily available than the beryllium metal.