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Flying the ILS
When you “Activate?”an ILS
approach, automatic switching of
the external CDI is enabled (unless
turned off from the CDI/Alarms
Page). When you are established
on the inbound course to the FAF,
the external CDI guidance will
automatically switch from “GPS”
(shown in green text) to “VLOC”
(shown in white text). If you have
forgotten to activate the ILS fre-
quency (step #4 below), automatic
selection of “VLOC” will not occur.1. Within 30 nautical miles of KFLG, the
GNS 430 will switch from enroute
mode to terminal mode and the CDI
scale will transition from 5.0 to 1.0
nautical miles, full scale deflection.
2. If you haven’t already activated the approach (in steps on previous page), be sure to do so when
cleared for the approach. See page 69, step #4 for a description of this operation.
3. As you approach the IAF (SHUTR), a waypoint alert (“NEXT DTK 030°”) will appear in the lower
right corner of the screen.
4. If you haven’t already done so, press
to activate the ILS frequency. If you forget this step, the
GNS 430 will display a reminder message (within 3 nm of the FAF) to activate the ILS frequency.
5. As the distance (DIS) to the IAF approaches zero, the alert is replaced by a turn advisory (“TURN
6. Fly the outbound course (030°), keeping the needle centered on the external CDI (or HSI).
Once you have flown approximately one minute past SHUTR intersection, the alert message
“STARTPROC TRN” will appear in the lower right corner of the screen (if you haven’t already
begun the procedure turn).
DO NOT USE FOR
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8. Turn right to a heading of 075° to initiate
the procedure turn. The GNS 430 will not
guide you through the turn. (The proce-
dure turn is displayed on the map page
and indicated as the active leg on the
default NAV and active flight plan pages.)
The external CDI needle will start moving
to the left.
9. After approximately one minute, make a
180° left turn to a heading of 255° to
intercept the ILS. The GNS 430 will
sequence to the inbound leg and “NEXT
DTK 210°” will appear in the lower right
corner of the screen. CDI coupling will
automatically switch from the “GPS”
receiver to the “VLOC” receiver as you
complete the inbound turn. (If the ILS fre-
quency has not been activated, per step
#4, this automatic CDI switch will not
10. As the CDI needle starts to center, make
a left turn to 210° to track the ILS
11. As you approach the FAF (SHUTR), “0.30nm” will appear in the lower left corner of the screen —
indicating a CDI scale transition from 1.0 to 0.3 nautical miles, full scale deflection. (This scale tran-
sition applies only to the default NAV page’s on-screen CDI, since the external CDI or HSI is now
coupled to the VLOC receiver. GPS approach mode will NOT be activated for precision approach-
es, since the VLOC receiver MUST be used for primary navigation.)
DO NOT USE FOR
From this point on, primary navigation is provided by the VLOC
receiver. You may continue to use the GPS receiver for supplemental
navigation guidance only. ALSO, when using an external CDI (not
an HSI), expect reverse sensing when flying outbound on the
approach course or when flying a back course approach.
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12. Also as you approach SHUTR, a
waypoint alert (“NEXT DTK
210°”) will appear in the lower
right corner of the screen.
13. As you cross SHUTR, the desti-
nation sequences to the MAP
(“RW21”, the runway threshold).
With the needle on the external
CDI (or HSI) centered, fly toward
the MAP, observing the altitude
minimums dictated by the
approach plate. (When viewing
the map page, you’ll note that
the final course segment is dis-
played in magenta — the active
leg of the flight plan always
appears in magenta — and a
dashed line extends the course
beyond the MAP.)
As you approach the MAP, a
waypoint alert (“APPRCHING
WPT”) will appear in the lower
As you cross the MAP, “SUSP”
will appear above the
indicating that automatic
sequencing of approach waypoints will be suspended at the MAP. A “from” indication will be dis-
played on the CDI and default NAV page, but course guidance along the final approach course
will continue. Do NOT follow this extended course. Follow published missed approach proce-
dures using the
key to initiate the missed approach sequence, as outlined on page 72.
DO NOT USE FOR
In addition to using the
key to initiate the missed approach sequence,
you may wish to press the
key to manually switch external CDI out-
put to the GPS receiver. “GPS” will be indicated above the
you leave the external CDI output on “VLOC” and are using an external
CDI (not an HSI), expect reverse sensing on the back course of the ILS.
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Points to R
• The GNS 430 is designed to complement your printed approach plates and
vastly improve situational awareness throughout the approach. However, you
must always fly an approach as it appears on the approach plate.
• The active leg (or the portion of the approach currently in use) is depicted in
magenta on the Map Page. As you fly the approach, the GNS 430 will automati-
cally sequence through each leg of the approach unless "SUSP" appears above
the OBS key. "SUSP" indicates that automatic sequencing of approach way-
points is suspended on the current leg and normally appears at holding patterns
and upon crossing the missed approach point (MAP).
Points to R
• The default factory setting will allow the CDI output to automatically switch
from the GPS receiver to the VLOC receiver. If the "ILS CDI Capture" setting
is changed to "Manual", you must determine when to select "GPS" or "VLOC"
guidance during the approach. Remember, "VLOC" is required for the final
course segment from final approach fix (FAF) to MAP.
• If the CDI output has not automatically switched from GPS to ILS by 2.0 nauti-
cal miles prior to the FAF, you must manually switch to the VLOC receiver by
. Verify that "VLOC" is displayed directly above the
• Automatic switching of CDI output is available for ILS, localizer, SDF and
LDA approaches. Automatic CDI switching is not
available for backcourse
• When flying an approach with the autopilot coupled, you must monitor system
functions at all times and verify that the autopilot and external CDI (or HSI)
switches to the VLOC receiver with sufficient time to capture and track the
approach course. Switching to "VLOC" late in the approach may not provide
the autopilot enough time to respond and intercept the approach course prior to
the FAF (depending upon the performance characteristics of your autopilot and
aircraft). In such cases, you should manually fly the approach or refer to the
documentation provided with your autopilot.
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• When an ILS approach is first selected and "loaded" (or "activated"), the ILS
frequency is automatically placed in the standby field. In order to fly the final
course segment of the ILS approach, you must place the ILS frequency in the
active frequency field by pressing
V. If you forget to do this, a "Select appro-
priate frequency for approach" message will appear within 3.0 nautical miles
of the FAF.
• When flying a localizer-based approach (other than backcourse) with automat-
ic CDI switching enabled:
1. "GPS" guidance is used while flying outbound and on the initial portion of the procedure
2. "VLOC" guidance is used on the remainder of the approach from the time you turn
inbound on the procedure turn.
3. The localizer frequency must be active to use "VLOC" guidance.
• When flying a localizer-based approach with automatic CDI switching disabled:
1. You may select "VLOC" guidance at any point on the approach prior to reaching the
2. The localizer frequency must be active to use "VLOC" guidance.
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