Honeywell KLN 900s, Pilot'S Manual

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5-33
RAIM (Receiver Autonomous Integrity Monitoring) is a
technique whereby the KLN 900 determines the integrity
of the GPS navigation signals using only GPS signals or
GPS signals augmented with altitude. This determina-
tion is achieved by a consistency check of the satellites.
The mode of flight (Oceanic, En route, Terminal, or
Approach) significantly impacts the satellite availability
required for RAIM. Since Approach mode has the
strictest requirements, you may have a RAIM YES indi-
cation on the STA 2 page and still be unable to transi-
tion from Approach ARM to Approach active (APR)
mode if terminal RAIM is available but approach RAIM
is not available. In summary, you will not be able to use
the KLN 900 for an approach unless approach RAIM is
available. A RAIM WARN indication means that an
inconsistency has been detected in the information
received from the satellite constellation. You should
cross check your position using other equipment if this
warning appears.
FDE (Fault Detection and Exclusion) is a technique
whereby the KLN 900 utilizes redundant GPS measure-
ments to provide independent monitoring of satellite
health. The detection function refers to the capability to
detect a satellite failure that affects navigation, while the
exclusion function refers to the capability to exclude a
failed satellite from the solution to prevent a satellite fail-
ure from affecting navigation. The availability of FDE is
primarily of interest to pilots who are using the KLN 900
for primary means oceanic/remote operation (see
Chapter 9). If FDE is active and a satellite has been
excluded, a “SV XX BAD” message will appear at the
bottom of the STA 2 page where XX is the designator of
the excluded satellite.
NOTE: The PreFlight software program (described in
appendix F) allows you to predict RAIM and FDE cover-
age along a flight plan. For more detailed information
about RAIM and FDE, please refer to the PreFlight
Version 2.0 User’s Manual which is stored on the
PreFlight diskettes.
5.8.3 Determining KLN 900 Software Status (STA 3)
The Status 3 page (figures 5-107A and 5-107B) displays
the software revision status of the KLN 900 host com-
puter and of the GPS receiver. If for some reason your
KLN 900 requires service, the information on this page
may be useful.
5.8.4 Determining KLN 900 Operational Time
(STA 4)
The Status 4 page displays the KLN 900’s total opera-
tional time and also the number of times the unit has
been turned on (figure 5-108). Kind of like having a built
in Hobbs meter, isn’t it! These values are set to zero if
the KLN 900’s nonvolatile memory is cleared.
Rev 2
Figure 5-107A
SOFTWARE |
HOST 03 |
RCVR 20 |
|
|
|
STA 3
Figure 5-108
TOTAL TIME |
1364 HR|
PWR CYCLES |
581 |
|
|
STA 4
For information about the STA 5 RAIM Status page, refer to Section 6.1.9.
Figure 5-107B
SOFTWARE |
HOST |
01583-0040|
01612-0001|
RCVR |
01621-0001|
STA 3