The Federal Aviation Administration and National Aeronautics and Space Administration are researching several problems targeted at improving airport capacity. Among the foremost of these problems is the issue of improving the operational use of runways. The efficiency of runway usage is dictated...

In this paper, we focus on a useful modeling concept that is frequently ignored while formu lating discrete optimization problems. Very often, there exists a natural symmetry inherent in the problem itself that, if propagated to the model, can hopelessly mire a branch-and-bound solver by...