Garmin GNS 430 Pilot's Manual & Reference page 195

When does the CDI scale change, and what does it change to?
The GNS 430 will begin a smooth CDI scale transition from the 5.0 nm (enroute/oceanic mode)
to the 1.0 nm (terminal mode) scale 30 nm from the destination airport (see left). The CDI scale will
further transition to 0.3 nm (approach mode) at 2 nm prior to the FAF during an active approach.
MAP
Approach
0.3 nm
FAF
2 nm
1 nm
Terminal
1 nm
1 minute
30 nm
5 nm Enroute/Oceanic
CDI Scale Transition
If you are in a missed approach situation, and would
like to return the CDI to the 1 nm scale, activate the
missed approach sequence by pressing the O key,
as described on page 72. The CDI scale will also be
1.0 nm (terminal mode) within 30 nm of the departure
airport.
Why does my CDI not respond like a VOR when OBS mode is active?
Unlike a VOR, the CDI scale used on GPS equipment is based on the cross-track distance to the desired
course, not an angular relationship to the destination (see right). Therefore, the CDI deflection on the GPS
will be constant regardless of the distance to the destination, and will not become less sensitive when you are
further away from the destination. For more information on the CDI scale, see page 153.
What is the correct missed approach procedure? How do
I select the missed approach holding point?
To comply with TSO specifications, the GNS 430 will not automatically
sequence past the MAP. The active-to waypoint will sequence to the first
waypoint in the missed approach procedure, whenever the
pressed AFTER crossing the MAP. All published missed approach proce-
dures must be followed, as indicated on the approach plate.
To execute the missed approach procedure prior to the MAP (not recom-
mended), select the active flight plan page and use the
ing it twice) to activate the missed approach portion of the procedure, as
described on page 65.
TROUBLE-
SHOOTING
O
key is
D
key (by press-
5 nm 5 nm
CDI Comparison: GPS vs. VOR
APPENDIX
D
2 2
nm nm
5 nm 5 nm
187