Garmin Flight Deck 100 User Manual

190-00728-04  Rev. A

®

473

The selected navigation receiver must have a valid VOR or LOC signal or active GPS course for the 

flight director to enter Navigation Mode.

Pressing the NAV Key selects Navigation Mode. Navigation Mode acquires and tracks the selected navigation

source (GPS, VOR, LOC). The flight director follows GPS roll steering commands when GPS is the selected
navigation source. When the navigation source is VOR or LOC, the flight director creates roll steering commands
from the Selected Course and deviation. Navigation Mode can also be used to fly non-precision GPS and LOC
approaches where vertical guidance is not required.

Backcourse Mode captures and tracks a localizer signal in the backcourse direction. The mode may be selected

by pressing the NAV Key. When making a backcourse approach, set the Selected Course to the localizer front
course.  The flight director creates roll steering commands from the Selected Course and deviation.

If the Course Deviation Indicator (CDI) shows greater than one dot when the NAV Key is pressed, the selected 

mode is armed. If the CDI is less than one dot, Navigation Mode is automatically captured when the NAV Key 
is pressed.  The armed annunciation appears in white to the left of the active lateral mode.

When the CDI has automatically switched from GPS to LOC during a LOC/ILS approach, GPS Navigation

Mode remains active, providing GPS steering guidance until the localizer signal is captured. LOC Navigation
Mode is armed automatically when the navigation source switch takes place if the APR Key is not pressed prior 
to the automatic source switch.

If Navigation Mode is active and either of the following occur, the flight director reverts to Roll Hold Mode

(wings rolled level):

• Different VOR tuned while in VOR Navigation Mode (VOR Navigation Mode reverts to armed)

• Navigation source manually switched (with the CDI Softkey)

• During a LOC/ILS approach, the FAF crossed while in GPS Navigation Mode after the automatic navigation

source switch from GPS to LOC

If the navigation source is VOR or localizer or OBS Mode has been enabled when using GPS, the Selected

Course is controlled using the CRS Knob corresponding to the selected flight director (CRS1 for the pilot 
side, CRS2 for the copilot side).

Pressing  the  CWS Button and hand-flying the aircraft does not change the Selected Course while in 

Navigation Mode. The autopilot guides the aircraft back to the Selected Course (or GPS flight plan) when the
CWS Button is released.