The purpose of this Recommendation is to describe the special maintenance procedures and facilities that are required for the maintenance of the Inmarsat aeronautical mobile telecommunication system via satellite, and to define interrelationship and interworking issues of such systems with terrestrial voice and data publidprivate networks. Wherever possible, the standard maintenance procedures and facilities specified in the M- and O-Series Recommendations, and appropriate X-Series Recommendations for data should be followed for the maintenance of these systems.