The problem is examined of retrofitting older generation aircraft with data link capability. The approach taken analyzes requirements for the cockpit interface, based on review of prior research and opinions obtained from subject matter experts. With this background, essential functions and constraints for a retrofit installation are defined. After an assessment of the technology available to meet the functions and constraints, candidate design concepts are developed. The most promising design concept is described in detail. Finally, needs for further research and development are identified. Mccauley, Hugh W. and Miles, William L. and Dwyer, John P. and Erickson, Jeffery B. Unspecified Center COCKPITS; DATA LINKS; DIGITAL SYSTEMS; RETROFITTING; HUMAN-COMPUTER INTERFACE; INSTALLING; SYSTEMS ENGINEERING; TECHNOLOGY ASSESSMENT...