Garmin GNC 420 Pilot's Manual & Reference page 178

APPENDIX D
TROUBLE-
SHOOTING
point (MAHP). If a missed approach is required, press the
MAHP. See page 70 for more information on missed approaches.
Why won't my unit automatically sequence to the next waypoint?
The GNC 420 will only sequence flight plan waypoints when automatic sequencing is enabled (i.e., no "OBS" or "SUSP" annunciation directly
O
above the key). For automatic sequencing to occur, you must also cross the "bisector" of the turn you are navigating. The bisector is a perpen-
dicular line between two flight plan legs which crosses through the waypoint common to both legs.
How do I skip a waypoint in an approach, departure or arrival?
The GNC 420 allows you to manually select any approach, departure or arrival leg as the active
leg of your flight plan. This procedure is performed from the active flight plan page by highlighting the
desired waypoint and pressing
The GPS will then provide navigation along the selected flight plan leg, so be sure you have clearance
to that position. See page 65 for more information.
How do I fly the GPS with an autopilot and HI heading bug?
If you do not have an HSI, you should make your course selections on the external CDI's OBS knob and the HI heading bug.
170
When should I use the O key to return
to auto sequencing, and what happens
when I do?
The most common application for using the
key is the missed approach. The GNC 420 will sus-
pend automatic waypoint sequencing (indicated by
a "SUSP" annunciation directly above the
see right) when you cross the missed approach point
(MAP). This prevents the GNC 420 from automatically sequencing to the missed approach holding
O
D E
twice, then to approve the selection (see illustration right).
O
O key;
key to return to automatic waypoint sequencing and sequence the approach to the