Honeywell BEDIX/KING GPS RNAV User Manual
Page 139
BENDIX/KING
KLN 90B
Rev 5, April/2003
10521I05.TDC
Page C-7
GPS Page/Laptop Messages
GPS Message
Definition
Suggested Action
RAIM not avail-
able
Cross check posi-
tion
This means there are
not enough satellites
available to compute in-
tegrity (RAIM).
1. The satellites are
blocked from view by
obstructions.
2. They are too low on
the horizon for use, or
too high for adequate
geometry.
3. There is a loss of sen-
sitivity in the antenna,
the coax, or the Receiv-
er Module.
The aircraft should be in an open area with good
visibility, and the SNR (Signal to Noise Ratio) on
the STA 1 or OTH 2 should be as noted below:
⋅
KLN 89s will usually have 6-8 satellites shown,
and the majority of their SNRs will be 7 to 9. SNRs
of 3 and below are unusable, 4 is marginal, and 5
through 9 are considered good.
⋅
KLN 90/900s will usually have 6-8 satellites
shown, and the majority of their SNRs will be 40s.
SNRs of 30 and below are unusable, 30-35 are
marginal and 35-48 are considered good.
If the SNRs are low, it could be one of the follow-
ing, in the order of probability:
1. Check the antenna coax and connection for
problems.
2. Verify that 5 volts is present at the antenna end
of the coax.
3. Substitute the receiver to check for sensitivity.
4. Substitute the antenna to check for sensitivity.
No RS-232 Data
There is no RS-232 data
at the RS-232 input
port.
The Air Data/Fuel Flow source is not providing RS
232 data to the GPS.
If no source of RS-232 is interfaced, the receiver
input must be jumpered back to the RS-232 out-
put on KLN 89/89Bs and KLN 90/90A/90Bs.
If no source of RS-232 is interfaced to a KLN 900,
the configuration may be set up wrong.
RCVR hardware
error:__
These are error codes
that are detected in the
GPS receiver.
Refer to the GPS Fault/Error Code table.
RAIM not avail-
able
Approach mode
inhibited
Predict RAIM on
OTH 3 or STA 5
This is a calculated pre-
diction of RAIM avail-
ability. The message
appears when integrity
monitoring (RAIM) is
predicted to not be
available at either the
FAF or MAP. The GPS
will not allow the unit to
go into APR ACTV
mode until conditions
improve.
This is a feature, not a system failure.
Turn to the OTH 3 or STA 5 page to perform a
RAIM prediction. It will give you an indication of
how long it will be until RAIM is available.
This prediction can also be performed prior to de-
parture to insure RAIM at your arrival.