Garmin GTN 625 Pilot's Manual page 471

14.3 RAIM Prediction
RAIM Prediction predicts if GPS coverage is available for your current location
or at a specified waypoint at any time and date. RAIM performs checks to ensure
that the GTN unit has adequate satellite geometry during your flight. RAIM
availability is near 100% in Oceanic, En Route and Terminal phases of flight.
Because the FAA' s 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 GTN unit automatically monitors
RAIM during approach operations and warns you if RAIM is not available. In
such cases, use a non-GPS based approach. RAIM prediction helps you plan for
a pending flight to confirm GPS operation during an approach.
RAIM prediction only predicts the availability of Fault Detection (FD) integrity
in the absence of SBAS corrections. It cannot predict the availability of LPV or
L/VNAV approaches. The FAA provides a NOTAM service for LPV approach
availability.
1. While viewing the Utilities page, touch the RAIM Prediction
key.
Touch to Select
Destination
Waypoint
Touch to Select
Local Arrival Date
Touch to Select
Local Arrival Time
2. Touch the Waypoint key and select the waypoint for RAIM
Prediction.
3. Touch the Arrival Date key and select the date of arrival at
the selected waypoint.
4. Touch the Arrival Time key and select the local time of
expected arrival at the selected waypoint.
190-01004-03 Rev. P
Figure 14-13 Utility RAIM Prediction Page
GTN 625/635/650 Pilot's Guide
Foreword
Getting
Started
Audio &
Xpdr Ctrl
Com/Nav
FPL
Direct-To
Proc
Wpt Info
Map
Traffic
Terrain
Weather
Nearest
Services/
Music
Utilities
System
Messages
Symbols
Appendix
Index
14-11