Garmin GPS 500 Pilot's Manual & Reference page 165

With the profile set, the vertical speed required (VSR)
is displayed on the Vertical Navigation Page. Expect the
following to occur when using the vertical navigation
feature:
• At one minute prior to reaching the initial descent
point, a message "Approaching VNAV Profile"
(Figure 9-5) occurs. The descent (or climb) angle
also locks to prevent changes in speed from alter-
ing the profile.
Figure 9-5 VNAV Profile Message
• If selected, the vertical speed required (VSR)
readout on the default NAV and map pages shows
the desired vertical speed to maintain the proper
descent (or climb) angle.
190-00181-60 Rev. G
• At 500 feet above (or below, for a climb) the
target altitude, an "Approaching Target Altitude"
message is provided (Figure 9-6). The VSR
readout on the Default NAV and Map Pages is
blanked out, at this point.
GPS 500 Pilot's Guide and Reference
SECTION 9
VERTICAL NAVIGATION
Figure 9-6 Target Altitude Message
9-3