Abstract: This invention relates to a method and apparatus for determining the relative position between the point of impingement of an electron beam on a work surface and the seam between parts to be welded. The seam is scanned by oscillating a low power electron beam along a path transverse to the scan. The variation in secondary electrons generated as the beam traverses the seam is detected and amplified. The amplified signal is then acted upon by an electronic converter which converts the wave form by instantaneously taking the Nth root at each point of the curve representing the wave form of the amplified secondary electron current wave form so as to improve the resolution of the signal and make possible an improved definition at the point of impingement of the beam with respect to the seam.

Abstract: An air launched weapon having wrap-around fins wherein the fins are provi with fences, slots and roll tabs to stabilize the roll-rate at all angles of attack.

Abstract: An apparatus and method for reducing the launch disturbance of a weapon se on a supersonic aircraft is disclosed. The apparatus comprises a flywheel rotatably mounted within the store. The flywheel is pre-spun before launch using internal rockets or ram air. The spining flywheel produces a gyroscopic effect which appreciably reduces launch disturbance and therefore increases accuracy.