Garmin GTN 625 Pilot's Manual page 163

For both methods, pressing the Visual key prompts a list of available visual
approaches. Once selected, the visual approach immediately loads and becomes
active.
Method 3: Visual approaches load from the PROC – Approach page or the
Airport Info - Procedures tab (similar to published instrument approaches). For
information on how to use this page, refer to section 6.4.
After a visual approach loads, a confirmation pop-up prompts, detailing
the glidepath angle (GPA) and threshold crossing height (TCH) when vertical
guidance is available. When unavailable it reads, "NO VERTICAL GUIDANCE."
Vertical Guidance Available
Figure 6-27 Visual Approach Configuration Pop-up
The availability of vertical guidance advisories for visual approaches is
dependent on terrain and obstacle obstructions along the approach path.
If no known obstructions are within the approach path, vertical guidance is
provided to a maximum distance of 28 NM from the runway. If there are known
obstructions further than 3 NM, but within the 28 NM maximum distance from
the runway along the approach, vertical guidance is limited to the approach path
portion after crossing the known obstructions. This is indicated by the shortened
magenta line on the map after loading the approach. If obstructions are within
3 NM to the runway, along the approach path, advisory vertical guidance is not
provided. Lateral guidance is always provided for visual approaches.
Published data is used to determine the visual approach GPA and TCH for
the selected runway. If no published data is available, the default is 3° GPA and
50 FT TCH.
NOTE: If the GTN does not have a valid terrain database, advisory vertical
guidance is not available for visual approaches.
NOTE: Only external CDI/VDI displays provide vertical deviation indications.
190-01004-03 Rev. P
Vertical Guidance Unavailable
GTN 625/635/650 Pilot's Guide
Foreword
Getting
Started
Audio &
Xpdr Ctrl
Com/Nav
FPL
Direct-To
Proc
Wpt Info
Map
Traffic
Terrain
Weather
Nearest
Services/
Music
Utilities
System
Messages
Symbols
Appendix
Index
6-23