Garmin 4XXW Series Manual - page 14
190-00356-03 Rev. D
AFMS, Garmin GNS 4XXW GPS/SBAS System
Page 14 of 19
FAA APPROVED
LOSS OF INTEGRITY (LOI) MODE:
Navigation ......................
FLY TOWARDS KNOWN VISUAL CONDITIONS
NOTE
All information derived from GPS will be removed.
NOTE
The airplane symbol is removed from all maps. The map will
remain centered at the last known position. “No GPS
Position” will be annunciated in the center of the map.
3.2.2
GPS APPROACH DOWNGRADE
During a GPS LPV, LNAV/VNAV, LP +V, or LNAV+V approach, if GPS
accuracy requirements cannot be met by the GPS receiver prior to the Final
Approach Fix, the GNS will downgrade the approach. The downgrade will
remove vertical deviation indication from the VDI and change the approach
annunciation accordingly from LPV, L/VNAV, LP +V, or LNAV+V to LNAV.
The approach may be continued using the LNAV only minimums. After the
Final Approach Fix has been passed, the approach will be aborted using the
indications described below.
During a GPS approach in which GPS accuracy requirements cannot be met by
the GPS receiver for any GPS approach type, the GNS will flag all CDI guidance
and display a system message “ABORT APPROACH - Loss of Navigation”.
Immediately upon viewing the message, the unit will revert to Terminal
navigation mode alarm limits. If the position integrity is within these limits
lateral guidance will be restored and the GPS may be used to execute the missed
approach, otherwise alternate means of navigation must be utilized.
3.2.3
LOSS OF COM RADIO TUNING FUNCTIONS
If alternate COM is available:
Communications .........................................................
USE ALTERNATE COM
If no alternate COM is available:
COM RMT XFR key (if installed) .......
PRESS AND HOLD FOR 2 SECONDS
NOTE
This procedure will tune the active COM radio the
emergency frequency 121.5, regardless of what frequency is
displayed on the GNS. Certain failures of the tuning system
will automatically tune 121.5 without flight crew action.