Garmin GPS 100 - Manual (Page 79)

12-4
9500 FT
5 NM
2500 FT 2500 FT
As you approach the course, CTS will slowly change and, once on course,
will be identical to the desired track.
12.4 VERTICAL NAVIGATION (Aviation Feature)
The vertical navigation (VNAV) function, introduced in Section 9.5, will help
you plan climbs and descents and will recommend the altitude at which you
should be in order to accomplish the desired maneuver.
Suppose you are travelling from Denver, Colorado to the Beech factory in
Wichita, Kansas. You are flying VFR at 9,500 feet MSL. You wish to be at
2500 feet (500 feet above Beech's traffic pattern altitude) 5 nautical miles
from the airport. Additionally, you wish to descend at 1000 feet per minute.
Enter the above data on the VNAV Planning page and turn the VNAV function
on.
The GPS 100 will inform you when it is time to begin your descent into Beech
with the message “START ALTITUDE CHNG”.
While descending, monitor the page for the recommended altitude during the
maneuver (displayed in the FROM altitude field).