Description / Abstract: This report represents a broad study of very high frequency (VHF) air-ground communications system improvements. The study includes: (1) gaining an understanding of the present VHF air-ground communications system, (2) developing future Air Traffic Service (ATS) and Aeronautical Operational Control (AOC) communications functional requirements and desirable features, (3) studying present system improvements, (4) selecting a future system candidate to pursue towards implementation, and (5) developing recommendations resulting from this study. Seven candidate future system alternatives were evaluated against future system requirements and desirable features and as a result of this study, six recommendations to pursue present and future system improvements were adopted.