The purpose of this paper is to present a commercial transport category airframe manufacturers perspective on the next generation flight deck data link system. An overview of the system components is discussed, along with specific operational capabilities. Flow diagrams are then presented for both received and initiated messages. Significant issues related to flight deck data link systems are also presented. Conclusions emphasize the conceptual nature of this implementation and its value as a functional model for the evaluation of issues related to the total aeronautical digital communication system.