In this paper, we consider the over-constrained Airport Gate Assignment Problem where the number of flights exceeds the number of gates available, and where the objectives are to minimize the number of ungated flights and the total walking distances or connection times. We design a greedy algorithm and use a Tabu Search meta-heuristic to solve the problem. The greedy algorithm minimizes ungated flights while providing initial feasible solutions while we devise a new neighborhood search technique, the Interval Exchange Move, which allows us flexibility in seeking good solutions, especially in case when flight schedules are dense in time. Experiments conducted give good results.