Garmin G3X Pilot's Manual page 381

2) Following the flight plan, the autopilot continues to steer the aircraft under
GPS guidance. Note that in GPS Navigation Mode, course changes defined
by the flight plan are automatically made without pilot action required.
DESCENT
While flying the arrival procedure, the aircraft is cleared for descent in preparation
for the approach to KCOS. Two methods are presented for descent:
• Indicated Airspeed descent (GMC 305 Only)– Indicated Airspeed Mode can be
used to descend to the Selected Altitude at a constant airspeed. This descent
method does not account for flight plan waypoint altitude constraints.
• VNAV descent – VNAV Mode is used to follow the vertical descent path defined
in the GPS flight plan. Altitude constraints correspond to waypoints in the flight
plan.
Indicated Airspeed descent (GMC 305 Only):
1) Select Indicated Airspeed Mode:
a) G3X: From the PFD or PFD Page, press the ALT Softkey and turn the
FMS Joystick to set the Selected Altitude to 10,000 feet.
b) GMC 305: Press the IAS Key to activate Indicated Airspeed Mode. The
annunciation 'IAS' appears next to the Airspeed Reference, which
defaults to the current aircraft airspeed. Selected Altitude Capture
Mode is armed automatically.
190-01115-00 Rev. K
Transition to GPS Flight Plan
Garmin G3X Pilot's Guide
AFCS
359