Garmin GNS 530 - Manual (Page 277)

GNS 530(A) Pilot’s Guide and Reference 190-00181-00 Rev. H
APPENDIX C
MAP DATUMS
C-3
NORMAL (no ‘OBS’
annunciator)
OBS
Automatic sequencing of
waypoints Manual sequencing- ‘holds’
on selected waypoint
Change in HSI does not
affect CDI deflection Manually select course to
next waypoint from HSI
Always navigates ‘TO’ the
active waypoint Indicates ‘TO’ or ‘FROM’
waypoint
Must be in this mode for
final approach course Cannot be set for final
approach course or
published holding patterns
When OBS mode is active, the GNS 530 allows the
pilot to select the desired course to/from a waypoint using
the HSI (much like a VOR) and display a to/from flag for
the active-to waypoint. If an external course input is not
available, the pilot may select the OBS course on-screen,
via a ‘Select OBS Course’ pop-up window. With OBS
mode cancelled, the CDI always displays a ‘TO’ indication
for the next waypoint once the aircraft has crossed the
active waypoint (provided the active waypoint is not the
last waypoint). Refer to Section 6.2 for an example using
the OBS Key.
One application for the OBS Key is holding patterns.
The OBS Key is used to suspend waypoint sequencing
and select the desired course along the waypoint side of
the hold. For many approach operations, setting and
resetting of waypoint sequencing is automatic. Holding
patterns that are part of an approach automatically
disable waypoint sequencing, then re-enable waypoint
sequencing after one time around the holding pattern.
A ‘SUSP’ annunciation appears directly above the OBS
Key (Figure C-3) to indicate that automatic waypoint
sequencing is temporarily suspended and course selection
is not available. If more than one trip around the holding
pattern is desired, press the OBS Key to again suspend
waypoint sequencing. An example of this operation is
an approach which begins with a holding pattern at the
initial approach fix (IAF). See Section 6.2, Flying an
Approach with a Hold for more information on the ‘SUSP’
annunciation and approaches with holding patterns.
Figure C-3 ‘SUSP’ Annunciation