Contingency Plans for Air Traffic Management

We present two heuristics based on constraint technology that solve the problem of generating air traffic management contingency plans, which are used in the case of a catastrophic infrastructure failure within EUROCONTROL, the European Organisation for the Safety of Air Navigation. Of the heuristics presented, one is based on constraintbased local search and tabu search, and the other one is a constraint programming and large neighbourhood search hybrid algorithm. The heuristics show that it is feasible to automate the development of contingency plans, which is currently done by human experts; this is desirable for several reasons, for example it would allow the contingency plans to be generated with an increased frequency. The generated plans were evaluated, by EUROCONTROL, to be as good as the human-made ones. 1 Air Traffic Management and Contingency Planning Air traffic management (ATM) at EUROCONTROL, the European Organisation for the Safety of Air Navigation, is about managing and ensuring a safe, efficient, and fair flow of air traffic, assuming a negligible amount of side-effects, such as adverse weather conditions. During normal operation, the Central Flow Management Unit (CFMU) of EUROCONTROL uses several stages, each in increasing detail, to satisfy its operational goals: 1. A strategic stage, taking place several months before the day of operation. 2. A pre-tactical stage that starts six days before the day of operation. 3. An online tactical stage during the day of operation. This stage is called the air traffic flow and capacity management (ATFCM) stage [2], and has two main functions: (a) Calculate the demand of each airspace volume using live flight plan information. (b) Adjust the number of allocated departure slots of the involved aerodromes, such that they optimise the objectives defined in the pre-tactical stage. These objectives typically include, but are not limited to, minimising the total flight delay and air volume overload. During an average day, the ATFCM unit handles approximately 30 000 flights spread over about 1 500 aerodromes. Flow identifier Flow description Time span Hourly rate EBBR1 From EBBR 00:00 – 06:00 2 To C EG EI K M 06:00 – 09:00 3 09:00 – 12:00 7 12:00 – 14:00 4