To help business aircraft operators cope with new Rnav routes and procedures that took effect last month, the FAA is developing a Web-based RAIM (receiver autonomous integrity monitor) prediction service that will be made available for general use by flight crews, according to NBAA. Some FMS manufacturers have said their Rnav systems do not comply with the criteria of Advisory Circular 90-100 for DME/DME-based Rnav, meaning operations with affected avionics should be based solely on GPS. Until its Web-based RAIM prediction tool is made available, RAIM prediction does not need to be performed for Rnav routes conducted in places where ATC provides radar monitoring or for Rnav departure/arrival procedures that have an associated “radar required” note on the chart.