Introduction
Future Air Navigation System (FANS) is aconcept that was developed by theInternational Civil Aviation Organization(ICAO) in partnership with Boeing, Airbus,Honeywell and others in the air transportindustry to allow more aircraft to safely andefficiently utilize a given volume of airspace.Today FANS is used primarily in the oceanicregions taking advantage of both satellitecommunication and satellite navigation toeffectively create a virtual radar environmentfor safe passage of aircraft. FANS plays akey role in supporting many of the evolvingCNS/ATM (Communication, Navigation,Surveillance / Air Traffic Management)strategies and mandates an evolution thathas been underway for more than ten years.Today, FANS-1 is the standard used onBoeing aircraft while the Airbus standard isknown as FANS-A. Both are consideredfirst generation FANS architectures. Secondgeneration FANS will be discussed underthe FANS Evolution paragraph.................