Garmin GNC 420W Pilots Guide - Page 161

• RAIM Prediction - Predicts if GPS coverage is available for the current location or at a specified waypoint at any time and date. Receiver Autonomous Integrity Monitoring (RAIM) performs checks to ensure that the GNC 420 will have adequate satellite geometry during the flight. RAIM availability is near 100% in Oceanic, Enroute, and Terminal phases of flight. Because FAA TSO requirements for non-precision approaches specify significantly better satellite coverage than other flight phases, RAIM may not be available when flying some approaches. The GNC 420 automatically monitors RAIM during approach operations and warn the pilot if RAIM is not available. In such cases, use an external LOC receiver instead for many of the non-precision and precision approaches stored on the Jeppesen NavData Card. RAIM prediction helps the pilot plan for a pending flight to confirm GPS operation during an approach. An 'INTEG' annunciation at the bottom left corner of the screen (Figure 9-32) indicates that satellite coverage is insufficient to pass built-in RAIM tests. When this occurs, the GPS receiver continues to provide navigation information, but should not be used for primary navigation guidance. Use an alternate navigation source. SECTION 9 AUX PAGES If a 'WARN' annunciation appears at the bottom left corner, GPS satellite coverage may be sufficient, but the GNC 420 has detected a position error which exceeds protection limits. In this condition, all GPS navigation data on the GNC 420 is disabled. Use an alternate navigation source. • Sunrise/Sunset - Allows the pilot to calculate the time of sunrise and sunset at any waypoint or the present position for a specified date. • Software Versions - Provides software version information for the operating software within the GPS receiver, COM transceiver, and main processor board. • Database Versions - Displays the current Jeppesen database type and expiration date, along with the version and type of built-in land database. • Terrain Database Versions - Displays the current version and area of coverage of each terrain and obstacle database. If a database is found to be missing and/or deficient, the TERRAIN system fails the self-test and issues a failure message. Figure 9-32 'INTEG' Annunciation 190-00140-20 Rev. K GNC 420(A) Pilot's Guide and Reference 9-13