GNC 420/420A Quick Reference
KEYS AND KNOBS 3 2 1 5 4 6 7 GNC 420 8 9 10 11 12 13 15 14 16 Figure 1-1 Keys and Knobs 8 ENT (enter) Small left knob 13 9 Large left knob 14 10 NRST 15 11 OBS 16 1 COM Power/ Volume 7 2 COM Flip-flop CLR (clear) Direct-to 3 4 5 6 RNG (map range) MENU 12 MSG (message) FPL (flight plan) PROC (procedures) Large right knob Small right knob Left-hand Keys and Knobs The COM Power/Volume Knob controls unit power and communications radio volume.
KEYS AND KNOBS Right-hand Keys and Knobs Bottom Row Keys The RNG Key allows the pilot to select the desired map range. Press the up arrow to zoom out to a larger area, or the down arrow to zoom in to a smaller area. The Direct-to Key provides access to the direct-to function, which allows the pilot to enter a destination waypoint and establishes a direct course to the selected destination. The MENU Key displays a context-sensitive list of options.
POWER ON 3) Once the self-test concludes, the Database Versions Page appears which shows the current database information on the NavData® Card and Terrain Data cards. Press the ENT Key to acknowledge the Database Page and proceed to the Instrument Panel Self-test Page. SCREEN LAYOUT (WINDOWS) The GNC 420’s display is divided into three separate windows (or screen areas). The left side of the display provides a COM Window (top two lines) and a userdefined data field below.
FREQUENCY SELECTION Selecting a frequency: 1) Turn the large left knob to select the desired megahertz (MHz) value. For example, the ‘135’ portion of the frequency ‘135.325’. Quickly tuning and activating the 121.500 emergency channel: Press and hold the COM Flip-flop Key for approximately two seconds. DATA ENTRY Data is entered in the GPS Window using the large and small right knobs. The large right knob is used to move the cursor about the page.
MAIN PAGE GROUPS Main Page Groups NAV Page Group The GNC 420’s main pages are divided into four separate page groups: NAV, WPT, AUX, and NRST. Each page group is comprised of multiple pages. The page groups are selected using the large right knob. The individual pages are selected using the small right knob. Page Groups NAV Group WPT Group AUX Group 7 NAV Pages 10 WPT Pages 4 AUX Pages NRST Group 8 NRST Pages The NAV Page Group includes seven pages.
DIRECT-TO NAVIGATION AUX PAGE GROUP Selecting a direct-to destination: The AUX Page Group includes four pages. Utility Flight Planning 1) Press the Direct-to Key. The Select Direct-to Waypoint Page appears, with the waypoint identifier field highlighted. 2) Use the small and large right knobs to enter the identifier of the desired destination waypoint. 3) Press the ENT Key to confirm the selected waypoint, and press the ENT Key again to activate the direct-to function.
DIRECT-TO NAVIGATION Selecting a direct-to destination from the Map Page: Selecting a direct-to destination by facility name or city: 1) Select the Map Page from the NAV Page Group. 1) 2) Press the small right knob to display a panning pointer. Press the Direct-to Key. The Select Direct-to Waypoint Page appears, with the waypoint identifier field highlighted. 2) Turn the small and large right knobs to place the panning pointer at the desired destination location.
VIEWING AIRPORT INFORMATION Selecting a nearby airport or a flight plan waypoint as a direct-to destination: 1) Press the Direct-to Key. 2) Turn the large right knob to highlight the nearest airport (NRST) or flight plan (FPL) field. 3) Viewing airport information: 1) Turn the large right knob to select the WPT Page Group. ‘WPT’ appears in the lower right corner of the screen. 2) Turn the small right knob to select the desired WPT page.
VIEWING AIRPORT INFORMATION Viewing airport information by facility name or city: 1) Select the Airport Location Page (see page 6). 2) Press the small right knob to activate the cursor. 3) Turn the large right knob to highlight the facility name (second line) or the city (third line) field. 4) Turn the small and large right knob to enter the facility name or city location of the desired destination waypoint.
DEFAULT NAV PAGE Default NAV Page TO/FROM Flag Active Leg of Flight Plan Quickly displaying the Default NAV Page: Course Deviation Indicator (CDI) From any page, press and hold the CLR Key for approximately two seconds. Selecting a different data item for any data field: 1) With the Default NAV Page displayed, press the MENU Key to display the Default NAV Page Menu. 2) The ‘Change Fields?’ option is already highlighted, so press the ENT Key to select this option.
MAP PAGE 4) Turn the small right knob to display the list of available data items. Continue turning the small right knob to select the desired data item from the list. The following symbols are used to depict the various airports and NAVAIDs on the Map Page: Symbol Description Airport with hard surface runway(s); (primary runway shown) Airport with soft surface runway(s) only Private Airfield Heliport VOR 5) Press the ENT Key to select the desired data item and return to the Default NAV Page.
FULL SCREEN MAP Selecting a different data item for any data field: 1) With Map Page displayed, press the MENU Key to display an options menu. 2) Turn the large right knob to highlight ‘Change Fields?’ and press the ENT Key. 3) Turn the large right knob to highlight the data field to be changed. 3) 4) Turn the small right knob to select the desired type of data for this field and press the ENT Key.
NAVCOM PAGE NAVCOM Page Inhibiting TERRAIN: 1) Select the TERRAIN Page and press the MENU Key. ‘Inhibit Terrain?’ is selected by default. The NAVCOM Page provides a list of the airport communication and navigation frequencies at the departure, enroute, and arrival airports. Departure, Enroute, or Arrival Airport 2) Assigned Frequency and Usage Information (When Applicable) Scroll Bar Press the ENT Key.
NEAREST AIRPORTS Scrolling through the list of frequencies: 1) Activate the cursor, if not already active, by pressing the small right knob. 2) Turn the large right knob to move the cursor through the list of frequencies. If there are more frequencies in the list than can be displayed on the screen, a scroll bar along the right-hand side of the screen indicates which part of the list is currently being displayed. Viewing a list of nearest airports: Press the NRST Key to display the Nearest Airport Page.
NEARBY AIRPORTS Viewing additional information for a nearby airport: Selecting a nearby airport as a direct-to destination: 1) Highlight the identifier of the desired airport by scrolling through the list, as described in the preceding procedure. 1) Press the Direct-to Key. The Select Direct-to Waypoint Page appears, with the waypoint identifier field highlighted. 2) Press the ENT Key to display the Airport Location Page for the selected airport.
FLIGHT PLANS Navigating a flight plan: Creating a new flight plan: 1) Press the FPL Key and turn the small right knob to display the Flight Plan Catalog Page. 1) Press the FPL Key and turn the small right knob to display the Flight Plan Catalog Page. 2) Press the MENU Key to display the Flight Plan Catalog Page Menu. 2) Press the small right knob to activate the cursor. 3) Turn the large right knob to highlight ‘Create New Flight Plan?’ and press the ENT Key.
SELECT AN APPROACH Editing a flight plan: 1) Press the FPL Key and turn the small right knob to display the Flight Plan Catalog Page. 2) Press the small right knob to activate the cursor. 3) Turn the large right knob to highlight the desired flight plan and press the ENT Key. 4) To add a waypoint to the flight plan, turn the large right knob to select the point to add the new waypoint. (If an existing waypoint is highlighted, the new waypoint is placed directly in front of this waypoint.
ACTIVATE AN APPROACH 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.
FLYING AN APPROACH Activating the approach with vectors to final: 1) 2) With an approach loaded in the active flight plan, press the PROC Key to display the Procedures Page. Turn the large right knob to highlight ‘Activate Vector-To-Final?’ and press the ENT Key. Guidelines for Flying an Approach Due to the variety of available approach procedures, the specific steps required will vary according to the approach selected.
FLYING THE MISSED APPROACH • A ‘START PROC TRN’ prompt will appear in the lower right corner of the display to advise the pilot when the aircraft is at a safe distance to initiate a procedure turn. The procedure turn is displayed on the Map Page, but guidance through the turn itself is not provided. • Alerts for proper holding pattern entry (e.g., ‘HOLD DIRECT’) are displayed in the lower right corner of the display.
Garmin International, Inc. 1200 East 151st Street Olathe, KS 66062, U.S.A. p: 913.397.8200 f: 913.397.8282 Garmin AT, Inc. 2345 Turner Road SE Salem, OR 97302, U.S.A. p: 503.391.3411 f: 503.364.2138 Garmin (Europe) Ltd. Liberty House, Bulls Copse Road Hounsdown Business Park Southampton, SO40 9RB, U.K. p: +44/ (0) 870.8501241 f: +44/ (0) 870.8501251 Garmin Corporation No. 68, Jangshu 2nd Road Shijr, Taipei County, Taiwan p: 886/2.2642.9199 f: 886/2.2642.9099 www.garmin.com © 2008 Garmin Ltd.
