Garmin GPS 155XL TSO - Manual (Page 90)

5. Transition to Active Approach Phase
The approach will automatically transition to the active approach stage and
the GPS APR annunciator will indicate an ‘ACTV’ status if the following
conditions are met:
a. The approach is armed
b. The aircraft is 2 nm from the FAF on an inbound course
c. The GPS SEQ switch is set to the ‘AUTO’ position
d. The FAF is the active-to waypoint
e. The GPS 155XL confirms that integrity monitoring will be available to
complete the approach
Once the active approach phase begins, the CDI scale will begin to gradual-
ly transition from the 1.0 nm scale to the 0.3 nm scale, and remain at the
0.3 nm scale from the FAF to the MAP unless the approach is cancelled by
pressing the external GPS APR switch, setting the GPS SEQ switch to
‘HOLD’ or by initiating a direct-to operation.
WARNING: You are not authorized to fly the final portion of the approach
unless the external GPS APR annunciator indicates an ‘ACTV’ status.
6. Missed Approach Procedure
The GPS 155XL’s automatic waypoint sequencing stops at the missed
approach point. Once you have crossed the MAP, the GPS 155XL will give
you the option of flying direct to the missed approach holding point:
a. Press the GPS APR switch to return the CDI to the 1.0 nm scale.
b. AFTER crossing the MAP, press
D, followed by E to fly directly to
the missed approach holding point.
WARNING! A direct course to the missed approach holding point may not
correspond to the published missed approach procedure. Always fly all
published procedures before selecting the holding fix on the GPS.
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SECTION
5
APPROACH NAV
Typical Approach
Procedures
TSO C-129a requires that satellite coverage and
navigational accuracy provided by the GPS system
meet minimum standards. A ‘No RAIM from FAF
to MAP’ message will appear if RAIM is predicted
to be unavailable for an approach. If you receive a
RAIM message, continue the approach ONLY if the
ACTV annunciator remains illuminated to the
MAP. If the ACTV annunciator does not stay illu-
minated, your HSI NAV flag will appear, and you
must fly the missed approach procedure.
GPS approaches must be in the current aviation
database to be approved.
155xlb manual 1/12/99 4:06 PM Page 80