Vertical Navigation Page - Garmin GNS 400W Pilot's Manual & Reference

2 - NAV PAGES
Satellite Status Page
• 3D Navigation —
The GPS receiver is in 3D navigation mode and
computes altitude using satellite data.
• 3D Differential Navigation— The GPS receiver is
in 3D navigation mode and differential corrections
are being used.
The Satellite Status Page also indicates the accu-
racy of the position fix, using Horizontal Figure of
Merit (HFOM), Vertical Figure of Merit (VFOM), and
Estimated Position Uncertainty (EPU). HFOM and
VFOM represent the 95% confidence levels in hori-
zontal and vertical accuracy. The lowest numbers are
the best accuracy and the highest numbers are worse.
EPU is the horizontal position error estimated by the
Fault Detection and Exclusion (FDE) algorithm, in feet
or meters.
56
NOTE Operating outside of an SBAS service
area with SBAS enabled may cause elevated EPU
values to be displayed on the satellite status
page. Regardless of the EPU value displayed, the
INTEG annunciation is the controlling indication
for determining the integrity of the GPS naviga-
tion solution.

Vertical Navigation Page

WARNING: VNAV is to be used for advisory
purposes only. VNAV messages or vertical speed
required should not be used to maintain terrain
or ATC clearances. Terrain and ATC clearances are
the sole responsibility of the pilot.
The 400W-series vertical navigation page (the last
NAV page) allows you to create a three-dimensional
profile which guides you from your present position
and altitude to a final (target) altitude at a specified
location. This is helpful when you'd like to descend
to a certain altitude near an airport. Once the profile
is defined, message alerts and additional data on the
default NAV and map pages will keep you informed of
your progress.
Target Target
Altitude Distance
VNAV is inhibited in the following conditions:
• Groundspeed is less than 35 knots
• No active flight plan or direct-to destination
• SUSP mode
• Vectors-to-Final mode
• VLOC mode
• After the FAF on an approach
190-00356-00 Rev G
Altitude Reference
(AGL or MSL)
Target Reference
Vertical Speed
Required
Page location in
NAV group
Vertical Speed
Desired