It is required by item 25.473 in CCAR-25 that the civil airplane landing loads design shall meet a series of requirements and assumptions. This paper has studied its content and corresponding verification method, including relations with other airworthiness requirements, acceptable verification methods, and how to select the important calculation input data, such as landing weight, drop velocity, landing attitude and loads cases, landing gear dynamic properties and friction factor. The results will contribute to the design and compliance activities for transport category airplanes landing loads.