(European Geostationary Overlay Service) European satellite navigation system in keeping with ICAO requirements, the goal of which is to improve the American Global Positioning System (– GPS) and the Russian GLONASS (–). Available in ECAC airspace as of 2004, EGNOS will provide flights in approach and departure phases and those En-Route (–) with the aid of satellite navigation (– SBAS) beginning in 2006.