Aircrew schedule generation using repeated matching

We consider the Aircrew Scheduling Problem of determining tours of duty (TODs) for aircrews, given a set of sectors (or flights) requiring regular crews. A regular crew consists of two crew members, but by including supplementary crew (a third pilot) on some sectors it is possible to extend duty periods to generate more cost efficient TODs. A related problem is thus to generate TODs for these third pilots, but the sectors requiring a third pilot are not known in advance. To solve these two related problems simultaneously, we apply a heuristic procedure that solves a sequence of matching problems, i.e. a repeated matching algorithm. Numerical results based on the solution of a real problem show that this approach is a valid and efficient method for solving the Aircrew Scheduling Problem, especially when there is the option of using supplementary crew to extend duty periods.