Garmin G1000 NXi Pilot's Manual page 33

Receiver Autonomous Integrity Monitoring (RAIM) is a GPS receiver function that performs a consistency
check on all tracked satellites. RAIM ensures that the available satellite geometry allows the receiver to
calculate a position within a specified RAIM protection limit (2.0 nautical miles for oceanic and enroute, 1.0
nm for terminal, and 0.3 nm for non-precision approaches). During oceanic, enroute, and terminal phases of
flight, RAIM is available nearly 100% of the time.
The RAIM prediction function also indicates whether RAIM is available at a specified date and time. RAIM
computations predict satellite coverage within ±15 min of the specified arrival date and time.
Because of the tighter protection limit on approaches, there may be times when RAIM is not available. The
system automatically monitors RAIM and warns with an alert message when it is not available. If RAIM is not
predicted to be available for the final approach course, the approach does not become active, as indicated by
the messages "Approach is not active" and "RAIM not available from FAF to MAP". If RAIM is not available
when crossing the FAF, the missed approach procedure must be flown.
Predicting RAIM availability at a selected waypoint:
1) Select the GPS Status Page.
2) If necessary, press the RAIM Softkey.
3) Press the FMS Knob. The 'Waypoint' field is highlighted.
4) Turn the small FMS Knob to display the Waypoint Information Window.
5) Enter the desired waypoint:
Use the FMS Knob to enter the desired waypoint by identifier, facility, or city name and press the ENT Key.
Or :
a) Turn the small FMS Knob counter-clockwise to display a list of flight plan waypoints (the FPL list is populated
only when navigating a flight plan).
b) Turn the small FMS Knob clockwise to display the Flight Plan, Nearest, Recent, or User waypoints, if
required.
c) Turn the large FMS Knob clockwise to select the desired waypoint. The system automatically fills in the
identifier, facility, and city fields with the information for the selected waypoint.
d) Press the ENT Key to accept the waypoint entry.
6) Use the FMS Knob to enter an arrival time and press the ENT Key.
7) Use the FMS Knob to enter an arrival date and press the ENT Key.
8) With the cursor highlighting 'Compute RAIM?', press the ENT Key. Once RAIM availability is computed, one of
the following is displayed:
• 'Compute RAIM?'—RAIM has not been computed for the current waypoint, time, and date combination
• 'Computing Availability'—RAIM calculation in progress
• 'RAIM Available'—RAIM is predicted to be available for the specified waypoint, time, and date
• 'RAIM not Available'—RAIM is predicted to be unavailable for the specified waypoint, time, and date
190-02177-00 Rev. A
Garmin G1000 NXi Pilot's Guide for Cessna Nav III
SYSTEM OVERVIEW
19