Abstract: Currently,the maJority of airport departure and arrival procedures are designed manually and drawn with the help of computer-aided software.There is still room for improvement in bringing airspace resources into full play.In order to provide effective decision support for actual procedure designers,an optimization methodology of single departure and arrival programming is proposed.Firstly,each route is modeled in three dimensions in compliance with the Required Navigation Performance (RNP),and flight restrictions such as obstacle avoidance are considered.Secondly,three different ways of obstacle avoidance aree proposed:bypassing clockwise or counter-clockwise along the obstacle boundary,or maintaining the current flight level below the obstacle.Then,a Branch and Bound (B&B) approach is developed,where the branching strategies corresponded to different ways of obstacle avoidance.Finally,the algorithm is tested for two different obstacle layout structures,and the computation time is compared with the A^* algorithm.The results show that,the algorithm can provide optimal routes avoiding obstacles and conforming to the RNP requirements in a short computing time.Moreover,by adJusting different weight coefficients in the obJective function,the procedure of continuous climbing or descending can be obtained,which has positive impact for aircraft noise and emission reduction.

Key words: Air traffic control, Airports, Branch and Bound method, Obstacle avoidance, Path planning