This SAE Aerospace Recommended Practice (ARP) applies to landing gear structures and mechanisms (excluding wheels, tires, and brakes) for all types and models of civil and military aircraft including all aircraft with vertical landing and crash attenuation requirements. All axles, wheel forks, axle beams, links, arms, mechanical and nitrogen/oil energy absorbers, lock assemblies, braces, trunnion beams, and truck beams etc., that sustain loads originating at the ground, and that are not integral parts of the airframe structure should be designed in accordance with this document. Hydraulic actuators (retraction, main and nose gear steering, positioning, and/or damping) should also be included in this coverage.