Garmin GTN 625 Pilot's Manual page 561

Message
VNAV -
Unavailable.
Excessive
crosstrack error.
VNAV -
Unavailable.
Excessive track
angle error.
VNAV -
Unavailable.
Parallel course
selected.
VNAV -
Unavailable.
Barometric altitude
lost.
WAYPOINT -
Arriving at [wpt
name].
Note 1: There are several reference datums that waypoints can be surveyed against.
TSO-C146 normally requires that all waypoints be referenced to the WGS84
datum, but allows for navigation to waypoints that are not referenced to the
WGS84 datum so long as the pilot is notified. Certain waypoints in the navigation
database are not referenced to the WGS84 datum, or their reference datum is
unknown. If this is the case, this message is displayed. Garmin cannot determine
exactly how close the non-WGS84 referenced waypoint will be to the WGS84
datum that the GTN uses. Typically, the distance is within two nautical miles.
The majority of non-WGS84 waypoints are located outside of the United States.
190-01004-03 Rev. P
Description
Current crosstrack
exceeds limit, causing
vertical path guidance
to become invalid.
Current track angle
error exceeds limit,
causing vertical path
guidance to become
invalid.
Selecting a parallel
course causes vertical
path guidance to
become invalid.
A loss of data from
the barometric altitude
sensor causes vertical
path guidance to
become invalid.
User has configured
the arrival alarm and
is within the specified
distance.
Table 16-1 Messages
GTN 625/635/650 Pilot's Guide
Action
Navigate within 10 nm of flight
plan centerline, or edit flight plan
to allow for vertical navigation.
Navigate within 70° of active flight
plan course.
Disable parallel track if vertical
path guidance is desired.
Contact dealer for service.
No action is necessary; message is
informational only.
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
16-25