The project, funded by the Italian Space Agency, addressed the definition of architecture for precise and secure positioning in aeronautic applications. Novel strategies for the use of satellite navigation in all the flight phases have been addressed. NavSAS has been in charge of the definition of the airport system, and of hybrid NAV/COM positioning. The activities yielded the design of an architecture able to assure a “global integrity” of the position information both in a Terminal Based scheme (self-positioning) or a Network based Scheme (Monitoring and tracking). Such Integrity is essential in order to have a reliable services for mobile users in the airport areas.