Air Shield; Traffi C Warning Window - Garmin GNC 420 Pilot's Manual Addendum

Section 4
Ryan TCAD Interface
The Barometric Pressure fi eld is located in the
upper right-hand corner of the Traffi c Page.
TCAD 9900B Operating Modes:
GND: ground mode
TML: terminal mode
STD: standard mode
ENR: enroute mode
UNR: unrestricted mode
The modes APR (approach) and DEP (departure),
are displayed when in that mode, but are not
manually selectable.
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The second selectable field, located in the upper right-hand corner of the display, is the Barometric
Pressure field, which displays the Barometric Pressure in inches of mercury. The Barometric Pressure field
on the Traffic Page allows you to set the barometric pressure in the Ryan TCAD unit. Please, refer to the
TCAD Pilot' s Handbook for a detailed description of this feature.
To change the Barometric Pressure:
1. From the Traffic Page, press the cursor to highlight the Operating Mode field. Turn the large right
knob to select the Barometric Pressure Field. Use the small right knob to select the desired value
and press ENT. Note: when editing the value, use the large right knob to select the digit to edit.
2. Exit the field by pressing the CRSR button.
When the TCAD 9900BX model is interfaced there is an additional annunciation in the lower left
hand corner of the Traffic Page. This indicates the TCAD unit being in approach mode (APR) or if the
approach is armed (APR ARM).

Air Shield

Please, refer to the TCAD Pilot' s Handbook for a detailed description of the Air Shield.
Traffic Warning Window
When the unit is not on the traffic page and a traffic threat is imminent, the Traffic Warning Window
is displayed. The Warning Window shows a small thumbnail map and can display the Traffic Page (if the
user presses ENT) or return to the previous page (if the user presses CLR).
The Traffi c Warning Window is disabled when the aircraft ground speed is less than 30
knots or when an approach is active.