Beechcraft C-12C Operator And Technical Reference Manual page 524

TM 1-1520-218-10
Figure 3C-122. GPS RAIM
Table 3C-84. GPS RAIM Procedure
NO. DESCRIPTION/FUNCTION
Indicates the current state of active
1
RAIM solution.
2 Pressing line select key RAIM will
access the RAIM/prediction page.
3 Expected state of RAIM availability at
destination.
4 Select to
annunciations.
5 Indicates Estimated Time of Arrival at
destination.
6 Destination of interest for RAIM
The FMS-800 provides an active RAIM solution
at present position. By tracking GPS satellite state-of-
health and orbital geometry, the FMS-800 is capable
of determining when the GPS navigation solution is
degraded or suspect due to satellite failures. If the
GPS receiver is unable to provide a RAIM solution due
to satellite tracking problems or problems with the
satellite constellation
annunciation is shown to inform the crew of the
absence of RAIM protection.
period, the GPS navigation
acceptable, but the integrity of that solution will be
indeterminate. During normal GPS navigation with an
3C-170
disable nuisance RAIM
geometry, a NO
During a NO RAIM
solution may
active RAIM solution, if the GPS receiver determines
that there is an inconsistency in the GPS navigation
solution, a RAIM alert will be provided to inform the
crew of a degraded GPS navigation solution. When
an alert is indicated, the crew should compare the
GPS-based navigation solution with other available
sensors (INU, TACAN, and VOR/DME) to ensure the
GPS navigational
unacceptable, select a non-GPS based navigation
solution on the lateral steer page, Figure 3C-118, until
the integrity of the GPS navigation solution is restored.
The current state of the GPS RAIM solution is
provided on the Primary GPS INAV page as follows:
1. NO RAIM when RAIM processing is
unavailable.
2. RAIM ACT when RAIM processing is
actively performing integrity checks.
3. RAIM WRN when RAIM has detected an
inconsistency.
The line select key next to RAIM on the
RAIM/prediction page will enable or disable the RAIM
annunciations.
annunciations are inhibited and the pilot advisories
regarding GPS integrity performance will be only
available on the GPS INAV page. RAIM annunciations
should only be disabled if a failure is suspected in the
GPS receiver
Annunciations
whenever the FMS is powered on or enters the
terminal area.
To request the availability of approach RAIM at a
destination airport, enter the identifier of the airport in
the top line of the RAIM/Prediction page. Enter the
ETA in UTC.
calculation, the FMS-800 will display the availability of
approach RAIM on the page information line.
availability applies to a period from 15 minutes prior to
the entered ETA until 15 minutes after the ETA. A
predictive RAIM solution only provides an indication of
the availability of RAIM protection that is expected at
the destination
characteristics of the GPS constellation. It does not
provide an actual integrity determination at the desired
location.
Control Page.
RAIM
GPS Selective Availability/Antispoofing control page.
From the IDX page, select SA/AS to access the
SA/AS control. From this page, the current status of
be
GPS receiver keying is displayed, with two selections
for mission duration and SA/AS mode selection. GPS
accuracy is acceptable.
When OFF is selected, RAIM
causing nuisance
will be automatically
After performing the predicted
based on the
(d) Selective Availability/Antispoofing
The FMS-800 provides access to a
If
annunciations.
re-enabled
This
current orbital