Abstract: System for clearing both light and heavy obstacles, in which one or more flying metal plates are propelled against heavy obstacles by explosive forces which also expand a folded continous rod member into a curvilinear, generally annular configuration that cuts through light obstacles such as concertina wire in the process of unfolding.

Abstract: A method for dissipating static electrical energy from air cushion vehicles hen operating more particularly in cold, low humidity environments, which method involves fabricating the skirt assembly from a flexible sheet material of at least semiconductive character which will provide a suitable dissipating grounding pathway to discharge potential static electrical energy generated during the aforesaid operation thereof. The method includes utilizing a coated flexible fabric material having at least one of its opposite surfaces coated with an elastomeric abrasion-resistant material, and embedding a plurality of electrically conductive flexible strands at least partially within said flexible fabric material, or alternatively embedding electrically conductive particles or fibers in a generally uniformly manner throughout a forming of its elastomeric composition.

Abstract: An aerial flare having a safe-and-arm ignition system in which a radially vable valve element or slider is retained in a safe position obstructing ignition ports by engagement of the slider with interior walls of the flare casing. To deploy the flare, an expulsion charge is electrically detonated, ruptures a frangible barrier, ignites primer in the igniter, and expels igniter-illuminant assembly from the forward end of the casing. When the igniter clears the casing, the slider is powered radially outwardly under the force of a biasing spring to uncover the ignition ports so that the parts are in an arm position. The flaming primer then ignites the illuminant through the open ignition ports.