Garmin G1000 Reference Manual page 81

Turns are commanded in the same direction as Selected
Heading Bug movement, even if the bug is turned more
than 180° from the present heading (e.g., a 270° turn to
the right). However, Selected Heading changes of more
than 330° at a time result in turn reversals.
Navigation Mode (GPS, VOR, LOC)
NOTe: 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 on the HSI (GPS, VOR, LOC). The
flight director follows GPS roll steering commands when
GPS is the selected navigation source.
GPS Navigation
GPS is Selected
Navigation
Source
190-00384-09 Rev. A
Pitch Mode
Mode Active
Selected
Course
Figure 6-22 Navigation Mode
Garmin G1000 Cockpit Reference Guide for the Cessna Nav III
When the HSI is coupled to 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
glideslope capture is not required.
If the Course Deviation Indicator (CDI) shows greater
than one dot when the NAV Key is pressed, the selected
mode is armed. The armed annunciation appears in white
to the left of the active roll mode. For cases where the
projected course is offset a large distance from the present
course for turn anticipation, GPS Navigation Mode can
be activated with crosstrack error up to 10 nm when the
NAV Key is pressed.
Figure 6-23 GPS Navigation Mode Armed
Selected Altitude
Capture Mode
Armed
Active
Command Bars Indicate Left
Turn to Track GPS Course and Climb
to Intercept Selected Altitude
SECTION 6 – AUTOMATIC
FLIGHT CONTROL
6-19