Garmin GNC 420 - Manual (Page 19)

GNC 420/420A Quick Reference 190-00140-21 Rev. F
ACTIVATE AN APPROACH
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5) Turn the large right knob to highlight ‘Load?’
or ‘Activate?’ and press the ENT Key. (‘Load?’
adds the procedure to the flight plan without
immediately using it for navigation guidance.
This allows the pilot to continue navigating the
original flight plan, but keeps the procedure
available on the Active Flight Plan Page for
quick activation when needed.)
6) For precision approaches and some non-
precision approaches, a reminder window
appears indicating that GPS guidance on
such approaches is strictly for monitoring only
— use the external navigation receivers and
CDI (or HSI) for primary navigation. To confirm
this reminder, highlight ‘Yes?’ and press the
ENT Key.
Not all approaches in the database are approved for GPS
use. As the pilot selects an approach, a ‘GPS’ designation
to the right of the procedure name indicates the procedure
can be flown using the GPS receiver. Some procedures
do not have this designation, meaning the GPS receiver
may be used for supplemental navigation guidance only.
ILS approaches, for example, must be flown by tuning the
VLOC receiver to the proper frequency and coupling the
VLOC receiver to the external CDI (or HSI).
A selected approach may be activated or loaded. Once
an approach is selected, it may be activated for navigation
from the Procedures Page. Activating the approach
overrides the ‘enroute’ portion of the active flight plan,
proceeding directly to the ‘approach’ portion (for a full
approach, directly to the initial approach fix). Activating
the approach also initiates automatic CDI scaling transition
as the approach progresses.
In many cases, it may be easiest to ‘Load’ the full
approach while still some distance away, enroute to the
destination airport. Later, if vectored to final, use the
following steps to select ‘Activate Vector-To-Final’—which
makes the inbound course to the final approach fix (FAF)
waypoint active. Otherwise, activate the full approach
using the ’Activate Approach?’ option.
Activating an approach:
1) With an approach loaded in the active flight
plan, press the PROC Key to display the
Procedures Page.
2) Turn the large right knob to highlight ‘Activate
Approach?’ and press the ENT Key.
The ‘Activate Vector-To-Final?’ option allows the pilot
to activate the final course segment of the approach. This
option assumes the pilot will receive vectors to the FAF
and provides guidance to intercept the final course, before
reaching the FAF.