In network centric operations, avionics on an aircraft will be both a source and destination of information. The U.S. Department of Defense (DoD) has mandated capabilities required for transforming to network centric operations. These capabilities are called out in the Joint Technical Architecture (JTA) Version 6.0 (Ref. 2). The Weapon Systems Domain, Aviation Subdomain, identifies preferred interoperability standards for communications, data links, navigation/landing aids, and identification aids. Communications, navigation, and surveillance (CNS) avionics systems and functions impacted by the JTA include nearly all avionics hardware, software, and the human system interface. Existing avionics architectures may require major changes for integration in network centric operations. A key question is whether these changes are affordable. The controller pilot data link communication (CPDLC) retrofit into existing commercial aircraft is expensive and many airlines are in bankruptcy or have a weak financial report. Most existing military aircraft have wiring installed during production, with few upgrades since the aircraft went into service. Aircraft still in the design phase will utilize a network centric architecture that will be upgradeable as technology advances provide new “plug and play” processors, displays, and sensors and the cost of new technology such as CPDLC will be built into the aircraft cost. Architecture. Network centric operations require integrated information from many avionics systems that were originally “stand alone” and implemented a function such as navigation, or had an output to the automatic flight control system. Many current avionics systems, both military and civilian, employ a federated architecture. The federated architectures are not highly integrated since they descend from stand-alone systems employed in analog avionics and first generation digital avionics. Current aircraft architectures and avionics compatibility with the capabilities required present interesting data flow challenges. Two key requirements that an architecture must provide are high bandwidth and low data latency. Technologies. Keys to implementation of net centric capabilities are software programmable radios, Gigabit Ethernet, and “smart” displays. The Joint Tactical Radio System (JTRS) software programmable radio plans to provide up to eight channels which must connect with a multiband antenna. The Gigabit Ethernet can be fiber or