This paper describes a subset of the findings of a simulation study conducted to explore the usefulness and usability of a prototype of the Surface Management System (SMS), designed to assist in expediting the movements of aircraft on the surface of a large airport. In particular, this paper focuses on the use of SMS by Traffic Management Coordinators (TMCs) in airport Air Traffic Control Towers. The overall study included three airport tower air traffic controllers supported by a traffic management coordinator working in a full mission simulation of air and surface traffic environment at the Dallas-Ft. Worth International Airport (DFW). During each of nine one-hour runs of the simulation, the controllers at the four positions were responsible for approximately 120 airline aircraft preparing for departure or arriving at the airport. The findings include results of behavioral protocols, questionnaires completed by the subjects immediately after each run, and knowledge elicitation interviews with the controllers who served as the TMC or TMC Assistant during the simulation.