Recent observational work of controller behavior in simulations of air traffic control sessions suggests that controllers formulate and modify their plans in terms of clusters of aircraft, rather than individual aircraft, and that they cluster aircraft based on their closeness in an abstract cognitive space, rather than simple separation in physical space. A mathematical model of that space is presented as a background for further work to determine the cognitive strategies that controllers use to navigate that space. The model is topologicals that neighborhood constraints play a central role; it is dynamic in that more than one topology interact to define its essential characteristics; and it is parametric in that an entire class of spaces can be obtained by varying the values of some parameters.