GPS 400 Pilot’s Guide and Reference
190-00140-60 Rev. E
APPENDIX C
TROUBLESHOOTING
C-4
When should I use the OBS key to return to
auto sequencing, and what happens when I do?
The most common application for using the
OBS
Key
is the missed approach. The GPS 400 suspends automatic
waypoint sequencing (indicated by a ‘SUSP’ annunciation
directly above the
OBS
Key; see Figure C-4) when the
aircraft crosses the missed approach point (MAP). This
prevents the GPS 400 from automatically sequencing
to the missed approach holding point (MAHP). If a
missed approach is required, press the
OBS
Key to return
to automatic waypoint sequencing and sequence the
approach to the MAHP. See Section 5.2, Flying the Missed
Approach for more information on missed approaches.
Figure C-4 ‘SUSP’ Annunciation
Why won’t my unit automatically sequence to
the next waypoint?
The GPS 400 only sequences flight plan waypoints
when automatic sequencing is enabled (i.e., no ‘OBS’ or
‘SUSP’ annunciation directly above the
OBS
Key). For
automatic sequencing to occur, the aircraft must also cross
the bisector of the turn being navigated. The bisector is
a perpendicular 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 GPS 400 allows the pilot to manually select any
approach, departure, or arrival leg as the active leg of the
flight plan. This procedure is performed from the Active
Flight Plan Page by highlighting the desired waypoint and
pressing the
Direct-to
Key twice, then press the
ENT
Key to approve the selection (Figure C-5). The GPS then
provides navigation along the selected flight plan leg, so
be sure to have clearance to that position. See Section 4.2,
Shortcuts for more information.
Figure C-5 Activate Leg Window
How do I fly the GPS with an autopilot and
heading indicator heading bug?
If the installation does not have an HSI, the pilot
should make the course selections on the external CDI’s
OBS
Knob and the heading indicator heading bug.
