Abstract: A cross tube for a helicopter skid landing gear, including a monolithic metallic tube having a central portion extending transversely between two end portions with longitudinal central axes of the central portion and of the end portions being located in a plane, where the central portion has inner and outer heights, the end portions each have inner and outer heights, and the inner and outer heights of one of the central portion and the end portion are respectively greater than the inner and outer heights of the other of the central portion and the end portion. A skid tube with two portions with cross-sections having one or both of different orientations with respect to one another and different dimensions with respect to one another, and a method of forming a structural tube for a helicopter skid landing gear are also provided.

Abstract: A cross tube for a helicopter skid landing gear, including a monolithic metallic tube having a central portion extending transversely between two end portions with longitudinal central axes of the central portion and of the end portions being located in a plane, where the central portion has inner and outer heights, the end portions each have inner and outer heights, and the inner and outer heights of one of the central portion and the end portion are respectively greater than the inner and outer heights of the other of the central portion and the end portion. A skid tube with two portions with cross-sections having one or both of different orientations with respect to one another and different dimensions with respect to one another, and a method of forming a structural tube for a helicopter skid landing gear are also provided.

Abstract: The present invention is concerned a process for the regeneration of the spent silica gel used in chromatography and for any other kind of silica. The process comprises 5 main steps, namely: washing with an extractant of organic compounds and removing volatile organic materials remaining thereafter; oxidation to oxidize organic compounds remaining and, preferably, bleach the material; washing with an acid to remove soluble inorganic matter; heating to dry the material and combust any remaining organic compounds present; and recovering the regenerated material. Various optional steps can be added to the process.