T DLS is an integrated, high-availability platform designed to support application programs for Air Traffic Control (ATC) operations in Airport Traffic Control Towers (ATCTs). TDLS provides a user-friendly interface to air traffic control personnel to communicate with aircraft, airline/user computers, and FAA Air Route Traffic Control Center (ARTCC) host computers.

Upon completion of the TDLS Technology Refresh OT&E, BCI suggested developing a test tool to provide the capability of simulating and controlling responses from a service provider for TDLS. This would allow the FAA greater flexibility in scheduling testing/training time, since no support/coordination would be needed to test TDLS functions. The use of modems, and NADIN connectivity, would no longer be needed in the training environment. Also, the new test tool has the additional capabilities of message rejection, creating malformed messages, data logging on the test tool side, intentional time-outs, and a user interface. Connection status & message throughput on a per system basis has been provided to allow insight to the operations of PreDeparture Clearance (PDC) and Digital-Automatic Terminal Information Service (D-ATIS) data flow. This increased functionality will enable the FAA to perform much more thorough and realistic test/training scenarios.