Pilot-controller communications errors impact the safety and efficiency of the National Airspace System (NAS). The success of airline data link systems has prompted trials of data linking pre-departure Air Traffic Control (ATC) clearances, Automatic Terminal Information Service (ATIS), and weather services through these systems. Trials of oceanic satellite data line communications and projects by NASA Langley explore data linking tactical and strategic ATC clearances. Initial efforts show promise and point to human factors issues and cockpit display considerations which effect full implementation of these concepts. Data link has the potential to improve pilot-controller communications.