State aircraft equipage levels are high for Mode S and are slowly increasing for ADS-B OUT. It is important to ensure that forward fits and retrofits are implemented on the basis of compliant technical requirements which ensure adequate conformity and certification basis.
This technical leaflet responds to recent requests for support submitted to EUROCONTROL by a significant number of State aircraft operators but also to observations of transponder anomalies by Surveillance avionics monitoring (SAFPA). It aims to clarify and provide references concerning Mode S and ADS-B OUT technical requirements to be observed for State aircraft Mode S and ADS-B OUT installations.
Related and additional information concerning operational aspects can be found in the “Compendium of Aeronautical Information on Management of Flights by Mode S and ADS-B OUT Non-Equipped State Aircraft”, see link below.