March 28, 2014

In order to better serve operators, the FAA is introducing the ADS-B Service Availability Prediction Tool (SAPT), which is being implemented to meet the agency’s receiver autonomous integrity monitoring requirement (RAIM) check requirement.

The new website, at, is scheduled to be updated by the end of April 2014, after which the new services will be available and the new SAPT 2.0 web service definition language will be published and available for use. Flight-planning service providers will need to update their software programs as a result of this migration. With the migration and resulting interface change, RAIM queries made by flight operators or service providers will begin to fail in October, if not using the new site.

In addition to the RAIM predictability being added to the SAPT website, the new site is hosted at the FAA data center in Atlantic City, NJ, and will have a 24-hour call center. The new site will require the Google Earth browser plug-in or use of the Google Earth software.

All services at will continue to function as they currently do, until the site is permanently discontinued at the end of September 2014. This migration affects all users, including those who use the interactive tools and those who use the XML-based route-of-flight planning web service.

Currently, one method of confirming RAIM availability is by using the FAA en route and terminal RAIM prediction website at That site was set up in 2006, and currently records more than 45,000 daily transactions in support of flight operations.

In 2007, the FAA published Advisory Circular (AC) 90-100A – U.S. Terminal and En Route Area Navigation (RNAV) Operations, which reflects performance-based navigation criteria that has been harmonized with the International Civil Aviation Organization, and addresses RNAV systems using positioning inputs from GPS/GNSS and DME, and IRU.

This AC requires that when TSO-C129 sensor equipment is used to solely satisfy the RNAV requirement, GPS Receiver Autonomous Integrity Monitoring (RAIM) availability must be confirmed for the intended route of flight (route and time) using current GPS satellite information.

In 2010, the FAA published the ADS-B final rule, which will require that aircraft operating in certain airspace must have ADS-B Out capabilities by Jan 1, 2020. ADS-B is a surveillance technology that allows avionics to broadcast an aircraft’s identification, position, altitude, velocity, and other information to support ATC services in terminal and en route airspace and in airport surface operations.

For more information, including the new web service definition language detailing the required XML changes, or to be added to the mailing list for RAIM prediction, contact