Smooth airport pavement will help to increase pavement life, reduce structural damage to aircraft, and minimize complaints from pilots and passengers. The main objective of this study was to explore the relationship of an aircraft's vertical acceleration and gear loading to pavement-profile wavelength. The software package APRas, developed by APR Consultants, Inc., was used in this study to simulate an aircraft's vertical acceleration and pavement-loading responses. The simulation results indicated that the occurring wavelength of an aircraft's peak vertical acceleration and loading increased as the taxi speed increased and that pavement roughness had a greater influence on nose-gear loading than on main-gear loading. It was also found that airport pavement roughness was related more to flight safety than to passenger comfort. Pavement profiles of wavelengths between 3.3 and 10.0 m should be prevented in airport apron and taxiway pavements, and profiles of wavelengths between 10.0 and 50.0 m must be prevented in airport runway pavement. Regression models of peak acceleration and pavement loading wavelengths at various aircraft speeds, gross weights, and wheelbases were established. The widely used international roughness index, which is used to evaluate highway roughness, is not suitable in the assessment of airport-pavement roughness. The feasibility of adopting wavelet theory to establish a new evaluation index for airport pavement was confirmed. Further studies can be conducted to develop a new index to reflect the ride quality of passengers in the aircraft.