190-00962-02 Rev. A
Garmin G1000 Pilot’s Guide for the Diamond DA42NG
17
SYSTEM OVERVIEW
SY
STEM
O
VER
VIEW
FLIGHT
INSTRUMENTS
EIS
AUDIO P
ANEL
& CNS
FLIGHT
MANA
GEMENT
HAZARD
AV
OID
ANCE
AFCS
ADDITIONAL
FEA
TURES
APPENDICES
INDEX
RAIM PREDICTION
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. In G1000
systems with SBAS enabled, performing RAIM prediction is not necessary in most cases. However, if the
selected approach is outside the SBAS coverage area, it may be necessary to perform a RAIM prediction for
the intended approach.
NOTE:
Refer to the Airplane Flight Manual (AFM) to determine whether SBAS functionality is approved.
Because of the tighter protection limit on approaches, there may be times when RAIM is not available. The
G1000 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 message “Approach is not active”. If RAIM is not available when crossing the FAF, the missed approach
procedure must be flown.
Predicting RAIM availability:
1)
Select the GPS Status Page.
2)
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 and press the
ENT
Key (refer to Section 1.6 for instructions on data entry).
Or
:
a)
To use the present position, press the
MENU
Key.
b)
With ‘Set WPT to Present Position’ highlighted, press the
ENT
Key.
c)
Press the
ENT
Key to accept the waypoint entry.
6)
Enter an arrival time and press the
ENT
Key.
7)
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
