Garmin G900X Pilot's Manual page 518

AUTOMATIC FLIGHT CONTROL SYSTEM
Prior to descent path interception, the Selected Altitude must be set below the current aircraft altitude
by at least 75 feet. For the flight director to transition from Altitude Hold to Vertical Path Tracking Mode,
acknowledgment is required within 5 minutes of descent path interception by:
• Pressing the VNV Key
• Adjusting the Selected Altitude
If acknowledgment is not received within 1 minute of descent path interception, the white 'VPTH'
annunciation starts to flash. Flashing continues until acknowledged or the descent path is intercepted. If
the descent is not confirmed by the time of interception, Vertical Path Tracking Mode remains armed and the
descent is not captured.
In conjunction with the "TOD [top of descent] within 1 minute" annunciation in the Navigation Status Box
and the "Vertical track" voice message, VNV indications (VNV Target Altitude, vertical deviation, and vertical
speed required) appear on the PFD in magenta (Figure 7-11).
GPS is
Selected
Navigation
Source
502
Altitude Hold Armed, (Flashing Indicates
Mode Active Acknowledgment Required)
Selected
Altitude Below
VNV Target
Vertical
Deviation
Indicator
Terminal
Phase of
Flight
Figure 7-11 Vertical Path Capture
Garmin G900X Pilot's Guide
Vertical Path Tracking
VNV Target
Speed Bug
Altitude
Required
Vertical
190-00726-00 Rev. J