This paper presents sliding mode control (SMC) to aircraft automatic landing system (ALS), and uses genetic algorithm (GA), particle swarm optimization (PSO) and chaos particle swarm optimization (CPSO) to adjust controller parameters. When wind shear is encountered, the aircraft automatic landing system can not be used in such environment during serious wind speed changes. The proposed intelligent control scheme can help the pilots guide the aircraft to a safe landing in wind shear condition. PID control and cerebella model articulation controller (CMAC) are applied to the controller design.