Development of the EGNOS safety case

The European Tripartite Group (ETG), namely the European Union (EU), represented by the European Commission (EC), the European Space Agency (ESA) and the European Organisation for the Safety of Air Navigation (EUROCONTROL), are developing and implementing the European Geostationary Navigation Overlay Service (EGNOS). This service is planned to augment the navigation services of the American Global Positioning System (GPS) and the Russian Global Navigation Satellite System (GLONASS) to make them acceptable for safety-critical services for civil users. Although EGNOS is a multi-modal service (land, maritime, air), the different modes of transport have different requirements for regulating the safety of the services provided. This paper focuses on the methodology established by the civil aviation community for the Safety Regulation of the EGNOS service.