Abstract: A landing gear/tail skid having at least two pivot axes (22, 24) which are subject to relative motion in response to impact loads acting on the landing gear/tail skid (10) and a contact arm (18) disposed in combination with pivot axes (22, 24). The cartridge assembly (20) includes a housing member (30) having and internal chamber (38) and a telescoping piston assembly (40) mounting within the internal chamber (38) wherein the end portions of each are disposed in combination with one of the pivot axes (22, 24). The housing member (30) and piston assembly (40), in combination, define opposed bearing surfaces (36s, 46s) which act on an energy absorbing means (50) disposed within the internal chamber (38) and intermediate the opposed bearing surfaces (36s, 46s). The energy absorbing means (50) is operative, in response to impact loads coupled thereto by the opposed bearing surfaces (36s, 46s), to react impact loads below a threshold is value without change in its critical dimension (L.sub.

Abstract: An unmanned aerial vehicle having a toroidal fuselage structure that surrounds a pair of coaxial, multi-bladed, counter-rotating rotors. The toroidal fuselage structure is optimized to provide a highly efficient structure for reacting aerodynamic flight loads and rotor thrust loads of the UAV. The toroidal fuselage structure is further optimized to provide weight efficiency for minimizing power requirements.