Abstract: We adapt a new dynamic management scheme,actuated signal control,in the airport traffic administration.In a simplified airport model,the waiting time for take-off of any airplane is extended by a preset time interval,referred to as critical gap,from the time of an airplane arrival.The waiting phase switches when there is no arrival during critical cap.The airplanes waiting on the run-way start to take off and the ones in the air begin to wait till the coming of another switch.We develop a probabilistic model to study the expected value and variance of waiting time,for the purpose of comparing the strategy of actuated signal control and the classic fixing time interval alternating scheme.