Abstract: A switch comprising a first contact on a support surface, a switch housing sealingly secured to the support surface around the first contact to form a hermetically sealed chamber about the first contact, and a second contact movable in the chamber towards and away from the first contact, wherein the support surface is provided on a support having two or more protrusions protruding from the support surface and received in apertures formed in the switch housing to locate the switch housing relative to the first contact.

Abstract: A flexible adaptor mounts an aircraft gas turbine engine to a test stand. The adaptor includes an upper frame configured for mounting on the test stand, and a lower frame spaced from the upper frame and configured for supporting the engine. A spring flexibly joins the lower frame to the upper frame to simulate the flexibility of an aircraft wing which supports the engine during operation.

Abstract: A plug including an axial shaft, a mating end of which is spring coupled to a mating portion of a sealing plug. The other end of the shaft includes an externally threaded portion and a flanged portion. The sealing plug also includes an externally threaded portion and a flanged portion. The spring normally mates the shaft and sealing plug together so that the members are rotationally engaged. When the spring is suitably compressed, the mating relationship is removed so that the members are rotationally disengaged. The plug is particularly useful in conveniently sealing double wall combustors such as those in gas turbine engines.