Garmin GNC 420 PILOT GUIDE

GNC 420/420A

Pilot’s Guide and Reference

Part Number Change Summary

190-00140-20

(Rev. E)

Corrected print spec, added Data Field Conﬁguration info in Section 9

Revision Date of Revision Description

A B C D

7/99 8/00 5/03 8/06

Initial Release Revised and Redrawn Added FDE Section, update for SW 4.0 Changed to 8 inch x 8.5 inch format. Added TERRAIN, TIS and, Weather interface info, and misc. changes

RECORD OF REVISIONS

GNC 420/420A Pilot’s Guide and Reference

This manual reﬂects the operation of Main System Software version 5.01 or later. Some differences may be observed when comparing the information in this manual to other software versions.

Garmin International, Inc., 1200 East 151st Street, Olathe, Kansas 66062 USA p: 913.397.8200 f: 913.397.8282

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01251

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Website Address: www.garmin.com Visit the Garmin website for the latest updates and supplemental information concerning the operation of this and other Garmin

products.

Except as expressly provided herein, no part of this manual may be reproduced, copied, transmitted, disseminated, downloaded or stored in any storage medium, for any purpose without the express written permission of Garmin. Garmin hereby grants permission to download a single copy of this manual and of any revision to this manual onto a hard drive or other electronic storage medium to be viewed for personal use, provided that such electronic or printed copy of this manual or revision must contain the complete text of this copyright notice and provided further that any unauthorized commercial distribution of this manual or any revision hereto is strictly prohibited.

Garmin®, AutoLocate®, and PhaseTrac12® are registered trademarks of Garmin Ltd. or its subsidiaries and may not be used without the express permission of Garmin.

GDL™, GNC™, GTX™, and Spell’N’Find™ are trademarks of Garmin Ltd. or its subsidiaries and may not be used without the express permission of Garmin.

NavData® is a registered trademark of Jeppesen, Inc.

September 2006 190-00140-20 Rev. E Printed in the U.S.A..

GNC 420/420A Pilot’s Guide and Reference

TABLE OF CONTENTS

SECTION 1: INTRODUCTION ........................................... 1-1

1.1 Accessories and Packing List ................................. 1-1

1.2 Key and Knob Functions ......................................... 1-2

1.3 Takeoff Tour ............................................................... 1-5

SECTION 2: COM .................................................................. 2-1

2.1 Communicating Using the GNC 420 .....................2-1

SECTION 3: NAV PAGES .................................................. 3-1

3.1 Main Page Groups .................................................... 3-1

3.2 NAV Page Group ....................................................... 3-2

3.3 Default NAV Page .....................................................3-2

3.4 Map Page ...................................................................3-5

3.5 TERRAIN PAGE ......................................................... 3-15

3.6 NAV/COM Page ........................................................ 3-18

3.7 Position Page ..........................................................3-20

3.8 Satellite Status Page ............................................. 3-23

3.9 Vertical Navigation Page ...................................... 3-25

SECTION 4: DIRECT-TO NAVIGATION .........................4-1

4.1 Overview .................................................................... 4-1

SECTION 5: FLIGHT PLANS .............................................5-1

5.1 Flight Plan Catalog Page ........................................ 5-1

5.2 Active Flight Plan Page ........................................... 5-8

SECTION 6: PROCEDURES ............................................... 6-1

6.1 Approaches, Departures, and Arrivals ................. 6-1

6.2 Non-Precision Approach Operations .................... 6-3

6.3 Points to Remember for All Approaches ..........6-26

SECTION 7: WPT PAGES .................................................... 7-1

7.1 WPT Page Group ....................................................... 7-1

7.2 Airport Location Page ............................................. 7-4

7.3 Airport Runway Page .............................................. 7-5

7.4 Airport Frequency Page .......................................... 7-6

7.5 Airport Approach Page ...........................................7-8

7.6 Airport Arrival Page ............................................... 7-11

7.7 Airport Departure Page ........................................ 7-13

7.8 Intersection Page ................................................... 7-14

7.9 NDB Page .................................................................. 7-15

7.10 VOR Page ................................................................7-15

7.11 User Waypoint Page ............................................7-16

SECTION 8: NRST PAGES ................................................. 8-1

8.1 NRST Page Group .....................................................8-1

8.2 Nearest Airport Page ............................................... 8-4

8.3 Nearest Intersection Page ...................................... 8-6

8.4 Nearest NDB Page .................................................... 8-6

8.5 Nearest VOR Page ....................................................8-7

8.6 Nearest User Waypoint Page ................................. 8-7

8.7 Nearest Center (ARTCC) Page ................................ 8-8

8.8 Nearest Flight Service Station (FSS) Page ..........8-9

8.9 Nearest Airspace Page .......................................... 8-10

SECTION 9: AUX PAGES .................................................... 9-1

9.1 AUX Page Group .......................................................9-1

9.2 Flight Planning Page ................................................ 9-2

9.3 Utility Page .............................................................. 9-12

9.4 Setup 1 Page ...........................................................9-20

9.5 Setup 2 Page ...........................................................9-27

SECTION 10: TERRAIN INTERFACE ............................ 10-1

10.1 Introduction ..........................................................10-1

10.2 TERRAIN Operation ..............................................10-2

10.3 TERRAIN Alerts ......................................................10-6

SECTION 11: ADDITIONAL FEATURES ..................... 11-1

11.1 Trafﬁc Information Service (TIS) Interface ..... 11-1

11.2 Weather Data Link Interface ........................... 11-11

SECTION 12: FAULT DETECTION AND EXCLUSION ...

12-1

12.1 Detection and Exclusion ..................................... 12-1

12.2 Pre-Departure Veriﬁcation of FDE ....................12-2

SECTION 13: MESSAGES, ABBREVIATIONS, AND

TERMS ............................................................................ 13-1

NAV

13.1 Messages ................................................................ 13-1

13.2 Abbreviations ........................................................13-8

13.3 Navigation Terms ...............................................13-11

Appendix A: Data Card Use ..........................................A-1

Appendix B: Speciﬁcations ........................................... B-1

Appendix C: Map Datums ..............................................C-1

Appendix D: Troubleshooting Q & A .......................D-1

GNC 420/420A Pilot’s Guide and Reference

iii

WARNINGS,

CAUTIONS, AND NOTES

WARNING: Navigation and terrain separation must NOT be predicated upon the use of the TERRAIN function. The TERRAIN feature is NOT intended to be used as a primary reference for terrain avoidance and does not relieve the pilot from the responsibility of being aware of surroundings during ﬂight. The TERRAIN feature is only to be used as an aid for terrain avoidance and is not certiﬁed for use in applications requiring a certiﬁed terrain awareness system. Terrain data is obtained from third party sources. Garmin is not able to independently verify the accuracy of the terrain data.

WARNING: The terrain data should be used only as an aid for situational awareness. Terrain data must not

be used as the sole basis for decisions or maneuvers to avoid terrain or obstacles. Terrain data must not be used for navigation.

WARNING: The altitude calculated by GNC 420 GPS receivers is geometric height above Mean Sea Level and could vary signiﬁcantly from the altitude displayed by pressure altimeters in aircraft. GPS altitude should never be used for vertical navigation. Always use pressure altitude displayed by pressure altimeters in the aircraft.

WARNING: The Jeppesen database used in the GNC 420 system must be updated regularly in order to ensure that its information remains current. Updates are released every 28 days. A database information packet is included in the GNC 420 package. Pilots using an outdated database do so entirely at their own risk.

WARNING: The basemap (land and water data) must not be used for navigation, but rather only for non-navigational situational awareness. Any basemap indication should be compared with other navigation sources.

WARNING: For safety reasons, GNC 420 operational procedures must be learned on the ground.

WARNING: The United States government operates the Global Positioning System and is solely responsible

for its accuracy and maintenance. The GPS system is subject to changes which could affect the accuracy and performance of all GPS equipment. Portions of the Garmin GNC 420 utilize GPS as a precision electronic NAVigation AID (NAVAID). Therefore, as with all NAVAIDs, information presented by the GNC 420 can be

misused or misinterpreted and, therefore, become unsafe.

GNC 420/420A Pilot’s Guide and Reference

WARNINGS,

CAUTIONS, AND NOTES

WARNING: Use the GNC 420, Weather Data Link Interface, TIS, and TERRAIN at your own risk. To reduce the risk of unsafe operation, carefully review and understand all aspects of the GNC 420 Pilot’s Guide documentation and the Flight Manual Supplement. Thoroughly practice basic operation prior to actual use. During ﬂight operations, carefully compare indications from the GNC 420 to all available navigation sources, including the information from other NAVAIDs, visual sightings, charts, etc. For safety purposes, always resolve any discrepancies before continuing navigation.

CAUTION: The GNC 420 display lens is coated with a special anti-reﬂective coating that is very sensitive to skin oils, waxes, and abrasive cleaners. CLEANERS CONTAINING AMMONIA WILL HARM THE ANTI-REFLECTIVE COATING. It is very important to clean the lens using a clean, lint-free cloth and an eyeglass lens cleaner that is speciﬁed as safe for anti-reﬂective coatings.

CAUTION: The Garmin GNC 420 does not contain any user-serviceable parts. Repairs should only be made by an authorized Garmin service center. Unauthorized repairs or modiﬁcations could void both the warranty and the pilot’s authority to operate this device under FAA/FCC regulations.

NOTE: All visual depictions contained within this document, including screen images of the GNC 420 panel and displays, are subject to change and may not reﬂect the most current GNC 420 system. Depictions of equipment may differ slightly from the actual equipment.

NOTE: This device complies with part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

NOTE: Unless otherwise speciﬁed within this manual, the term ‘GNC 420’ applies to both the GNC 420 and the GNC 420A models. Please, note that the difference between these two models is indicated under ‘VHF COM Performance’ in the Speciﬁcations section of this manual (Appendix B).

NOTE: This product, its packaging, and its components contain chemicals known to the State of California to cause cancer, birth defects, or reproductive harm. This notice is being provided in accordance with California’s Proposition 65. If you have any questions or would like additional information, please refer to our website at www.garmin.com/prop65.

GNC 420/420A Pilot’s Guide and Reference

WARRANTY

LIMITED WARRANTY

This Garmin product is warranted to be free from defects in materials or workmanship for two years from the date of purchase. Within this period, Garmin will, at its sole option, repair or replace any components that fail in normal use. Such repairs or replacement will be made at no charge to the customer for parts and labor, provided that the customer shall be responsible for any transportation cost. This warranty does not cover failures due to abuse, misuse, accident, or unauthorized alterations or repairs.

THE WARRANTIES AND REMEDIES CONTAINED HEREIN ARE EXCLUSIVE AND IN LIEU OF ALL OTHER WARRANTIES EXPRESS OR IMPLIED OR STATUTORY, INCLUDING ANY LIABILITY ARISING UNDER ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, STATUTORY OR OTHERWISE. THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS, WHICH MAY VARY FROM STATE TO STATE.

IN NO EVENT SHALL GARMIN BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES, WHETHER RESULTING FROM THE USE, MISUSE, OR INABILITY TO USE THIS PRODUCT OR FROM DEFECTS IN THE PRODUCT. Some states do not allow the exclusion of incidental or consequential damages, so the above limitations may not apply to you.

Garmin retains the exclusive right to repair or replace the unit or software, or to offer a full refund of the purchase price, at its sole discretion. SUCH REMEDY SHALL BE YOUR SOLE AND EXCLUSIVE REMEDY FOR ANY BREACH OF WARRANTY.

To obtain warranty service, contact your local Garmin Authorized Service Center. For assistance in locating a Service Center near you, visit the Garmin Website at ‘http://www.garmin.com’ or contact Garmin Customer Service at 800-800-1020.

GNC 420/420A Pilot’s Guide and Reference

SECTION 1

INTRODUCTION

SECTION 1: INTRODUCTION

1.1 ACCESSORIES AND PACKING LIST

Congratulations on choosing the ﬁnest, most advanced panel mount IFR navigation/communication system available. The GNC 420 represents Garmin’s commitment to provide accurate, easy-to-use avionics.

Before installing and getting started with the GNC 420, please check to see that the package includes the following items. If any parts are missing or damaged, please contact a Garmin dealer immediately.

Standard Package:

• GNC 420 Unit

• NavData® Card

• Terrain Data Card

• Installation Rack

• Connectors

The Garmin dealer performs the installation and conﬁguration of the GNC 420. After installation, the NavData Card and the TERRAIN Data Card (if applicable) are installed into their correct slots on the front of the unit (Appendix A). The GNC 420 is secured in the installation rack with the proper wiring connections performed. A Garmin dealer can answer any questions about the installation such as location of antennas or any connections to other equipment in the panel.

NOTE: Help Garmin provide better support by

completing on-line registration. Registration ensures notiﬁcation of product updates, new products, and provides for lost or stolen unit tracking. Have the serial number of the GNC 420 available and connect to the website (www. garmin.com). Look for the product registration link on the home page.

• GPS Antenna

• Pilot’s Guide

• Quick Reference Guide

• 400/500-series Display Interface Pilot’s Guide Addendum

• Database Subscription Packet

• Warranty Registration Card

• GNC 420 Simulator CD-ROM

GNC 420/420A Pilot’s Guide and Reference

1-1

SECTION 1

GNC 420

INTRODUCTION

1.2 KEY AND KNOB FUNCTIONS

The GNC 420 is designed to make operation as simple as possible. The key and knob descriptions (Figure 1-1) provide a general overview of the primary function(s) for each key and knob. The takeoff tour (Section 1.3) is intended to provide a brief overview of the primary functions of the GNC 420.

Experiment with the unit and refer to the reference

sections for more information.

Data is entered using the large and small knobs. Experiment with them to become efﬁcient at entering data. This greatly reduces the amount of time spent operating the GNC 420 in ﬂight.

1-2

COM Power/

COM Flip-ﬂop

CLR (clear)

Direct-to

RNG (map range)

10 11 12

Figure 1-1 Keys and Knobs

Volume

GNC 420/420A Pilot’s Guide and Reference

ENT (enter)

Small left knob

Large left knob

NRST

OBS

MSG (message)

FPL (ﬂight plan)

PROC (procedures)

Large

right knob

Small right knob

SECTION 1

INTRODUCTION

Left-hand Keys and Knobs

The COM Power/Volume Knob controls unit power and communications radio volume. Press momentarily to disable automatic squelch control.

The large left knob is used to tune the megahertz (MHz) value of the standby frequency for the communications transceiver.

The small left knob is used to tune the kilohertz (kHz) value of the standby frequency for the communications transceiver.

The COM Flip-ﬂop Key is used to swap the active and standby COM frequencies. Press and hold to select emergency channel (121.500 MHz).

Right-hand Keys and Knobs

The RNG Key allows the pilot to select the desired map range. Use 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 (Section 4).

The MENU Key displays a context-sensitive list of options. This options list allows the pilot to access additional features or make settings changes which relate to the currently displayed page.

The CLR Key is used to erase information, remove map detail, or to cancel an entry. Press and hold the CLR key to immediately display the Default NAV Page.

The ENT Key is used to approve an operation or complete data entry. It is also used to conﬁrm information during power on.

The large right knob (CRSR) is used to select page groups: NAV, WPT, AUX, or NRST. With the on-screen cursor enabled, the large right knob allows the pilot to move the cursor about the page. The large right knob is also used to move the target pointer right (turn clockwise) or left (counterclockwise) when the map panning function is active.

The small right knob (CRSR) is used to select pages within one of the groups listed above. Press this knob momentarily to display the on-screen cursor. The cursor allows the pilot to enter data and/or make a selection from a list of options. When entering data, the small knob is used to select the desired letter or number and the large knob is used to move to the next character space. The small right knob is also used to move the target pointer up (turn clockwise) or down (counterclockwise) when the map panning function is active.

GNC 420/420A Pilot’s Guide and Reference

1-3

SECTION 1

INTRODUCTION

NOTE: Data is entered using the large and

small right knobs (Figure 1-2). Experiment with them to become efﬁcient at entering data. This will greatly reduce the amount of time spent operating the GNC 420 in ﬂight.

Figure 1-2 Blank Direct-to Page

NOTE: When the GNC 420 is displaying a list

of information that is too long for the display screen, a scroll bar appears along the right-hand side of the display (Figure 1-3). The scroll bar graphically indicates the number of additional items available within the selected category. To scroll through the list, press the small right knob to activate the cursor, then turn the large right knob.

Scroll

Bar

Bottom Row Keys

The NRST Key displays the Nearest Airports Page. Then, turning the small right knob steps through the NRST pages.

The OBS Key is used to select manual or automatic sequencing of waypoints. Pressing the OBS mode, which retains the current ‘active to’ waypoint as the navigation reference even after passing the waypoint (i.e., prevents sequencing to the next waypoint). Pressing the OBS Key again returns the unit to normal operation, with automatic sequencing of waypoints. When OBS mode is selected, the pilot may set the desired course to/from a waypoint using the ‘Select OBS Course’ pop-up window, or an external OBS selector on the HSI or CDI.

The MSG Key is used to view system messages and to alert the pilot to important warnings and requirements. See Section 12.1 for more information on messages.

The FPL Key allows the pilot to create, edit, activate, and invert ﬂight plans, as well as access approaches, departures, and arrivals. A closest point to ﬂight plan feature is also available from the FPL Key. See Section 5 for more information on ﬂight plans.

The PROC Key allows the pilot to select and remove approaches, departures, and arrivals from the ﬂight plan. When using a ﬂight plan, available procedures for the departure and/or arrival airport are offered automatically. Otherwise, the pilot may select the desired airport, then the desired procedure.

OBS Key selects

1-4

Figure 1-3 Scroll Bar

GNC 420/420A Pilot’s Guide and Reference

SECTION 1

INTRODUCTION

1.3 TAKEOFF TOUR

reading within this Pilot’s Guide includes:

Overview

The Garmin GNC 420 provides the pilot accurate navigational data and communication capability, along with non-precision and precision approach certiﬁcation in the IFR environment. The takeoff tour is designed to familiarize the pilot with:

• Powering up the unit

• Changing frequencies

• Entering data

• Performing a simple direct-to

• Selecting IFR procedures

• Using some limited ﬂight plans

In addition, this section brieﬂy covers the Default NAV Page, the Map Page, and the NAV/COM Page, which are available as part of the NAV Page Group. These pages are used for most of the in-ﬂight navigation.

The takeoff tour assumes that the unit and antennas have been properly installed and that the GNC 420’s default settings have not been changed. If any of the factory default settings (position format, units of measure, selectable ﬁelds, etc.) have been changed, the pictures shown here may not exactly match what is shown on the GNC 420. Prior to using the GNC 420 for the ﬁrst time, Garmin recommends that the aircraft be moved to a location that is well away from buildings and other aircraft so the unit can collect satellite data without interruption.

This takeoff tour is intended to provide a brief introduction of the GNC 420’s major features. Sections 2 through 12 of this manual describe these features and others in additional detail. Refer to these sections, as needed to learn or review the details regarding a particular feature.

Service staff is available during normal business hours (U.S. Central time zone) at the phone and fax numbers listed on page ii. Garmin can also be reached by mail (page ii) or at our website address, www.garmin.com.

Powering up the GNC 420

using the COM Power/Volume Knob at the top left corner of the unit. Rotating it clockwise turns unit power on and increases the COM radio volume. After turning the unit on, a welcome page (Figure 1-4) is displayed while the unit performs a self test, followed sequentially by the Land Data Page, then (if conﬁgured for TERRAIN) the Terrain Data Page, the Obstacle Data Page, and the Airport Terrain Data Page.

After becoming familiar with the basics, some suggested

• Flight plan features - Section 5

• IFR procedures - Section 6

• Waypoint information pages (database information) - Section 7

• Unit settings (conﬁguring the unit to the pilot’s preferences) - Section 9

If more information is needed, Garmin’s Customer

The GNC 420’s power and COM volume are controlled

Figure 1-4 Welcome Page

GNC 420/420A Pilot’s Guide and Reference

1-5

SECTION 1

INTRODUCTION

The Database Conﬁrmation Page (Figure 1-5) appears next, which shows the current database information on the NavData Card (with the valid operating dates, cycle number, and database type indicated). The database is

instruments are working properly, check for the following indications on the CDI/HSI , RMI, external annunciators,

and other connected instruments: updated every 28 days and must be current for approved instrument approach operations. Information on database subscriptions is available inside the GNC 420 package.

Figure 1-5 Database Conﬁrmation Page

Acknowledging the database information:

Press the

ENT Key.

Instrument Panel Self-test Page

Once the database has been acknowledged, the Instru-

indicates the currently selected OBS course, fuel capacity

(CAP), fuel on board (FOB), and fuel ﬂow (FF). The fuel

capacity, fuel on board, and fuel ﬂow may be manually

entered if the installation does not include connection to

sensors which automatically provide these ﬁgures.

ment Panel Self-test Page appears (Figure 1-6).

To ensure that the GNC 420 and any connected

• Course deviation - half left/no ﬂag

• TO/FROM ﬂag - TO

• Bearing to destination - 135°

• Distance to destination - 10.0 nautical mi.

• All external annunciators (if installed) - on

• Glideslope - half up/no ﬂag

• Time to destination - 4 minutes

• Desired

track - 149.5°

• Ground speed - 150 knots

The Instrument Panel Self-test Page (Figure 1-6)

Entering fuel capacity, fuel on board, or fuel ﬂow ﬁgures (if not provided by sensors):

1-6

Figure 1-6 Instrument Panel Self-Test Page

GNC 420/420A Pilot’s Guide and Reference

1) Turn the large

right knob to select the ‘CAP’,

‘FOB’, or ‘FF’ ﬁeld.

2) Turn the small and large

right knobs to enter

the desired ﬁgure (Figures 1-6 and 1-7), then press the ENT Key.

INTRODUCTION

Viewing the Checklists Page:

SECTION 1

Figure 1-7 Fuel Flow Selected

The Instrument Panel Self-test Page includes selections to set fuel on board (FOB) to full capacity and access the Checklists Page. This allows the pilot to quickly set fuel to full limits and display any checklists that have been entered, such as start up or takeoff checklists.

Setting fuel on board to full (if not provided by sensor):

1) Turn the large

right knob to highlight ‘Set Full

Fuel?’ (Figure 1-8).

1) Turn the large

right knob to highlight ‘Go To

Chklist?’ (Figure 1-9) and press the ENT Key.

Figure 1-9 ‘Go To Chklist?’ Highlighted

2) Turn the large right knob to select the desired

checklist, then execute each step (Section

9.3, Utility Page: Checklists) in the selected checklist.

3) After completing the desired checklist(s), press

the small right knob to return to the Checklists Page. Press the small right knob again to return to normal operation on the Satellite Status Page or the Map Page.

Figure 1-8 ‘Set Full Fuel?’ Highlighted

2) Press the ENT Key and verify that fuel on board

(‘FOB’) now matches the fuel capacity (CAP) ﬁgure. Fuel on board is reduced, over time, based on the fuel ﬂow (FF) ﬁgure.

GNC 420/420A Pilot’s Guide and Reference

4) Once instrument operation has been veriﬁed with the Instrument Panel Self-test Page displayed, press the

NOTE: The GNC 420 can hold up to nine checklists

with up to 30 entries in each checklist.

ENT Key.

1-7

SECTION 1

INTRODUCTION

Satellite Status Page

The Satellite Status Page (Figure 1-10) appears as the

GNC 420 attempts to collect satellite information.

An ‘Acquiring’ status is displayed on the Satellite Status Page, and the signal strengths of any satellites received appear as ‘bar graph’ readings. This is a good indication that the unit is receiving signals and a position ﬁx is being determined. Following the ﬁrst-time use of the GNC 420, the time required for a position ﬁx varies, usually from one to two minutes.

Figure 1-10 Satellite Status Page

If the unit can only obtain enough satellites for 2D navigation (no altitude), the unit uses the altitude provided by the altitude encoder (if one is connected).

The ‘INTEG’ annunciator (bottom left corner of the screen) indicates that satellite coverage is insufﬁcient to pass built-in integrity monitoring tests. In the example above, not enough satellites are being received to determine a position. The Satellite Status Page shows the ID numbers for the satellites and the relative signal strength of each satellite received (as a bar graph reading).

‘Searching Sky’ indicates that satellite almanac data is not available or has expired (if the unit hasn’t been used for six months or more). This means the unit is acquiring satellite data to establish almanac and satellite orbit information, which can take ﬁve to ten minutes. The data is recollected from the ﬁrst available satellite. The Satellite Status Page displays a ‘Search Sky’ status, and the message annunciator (MSG), above the MSG Key also ﬂashes to alert the pilot of a system message, ‘Searching the Sky’.

Viewing a system message:

Press the

MSG Key (Figure 1-11).

The Message Page appears and displays the status or warning information applicable to the receiver’s current operating condition.

Figure 1-11 Message Page

Returning to the previous page after viewing a message:

Press the

NOTE: The GNC 420 utilizes certain software

algorithms to ensure reliable GPS receiver operation. Receiver Autonomous Integrity Monitoring (RAIM) and Fault Detection and Exclusion (FDE) are two examples. These features allow navigation during Oceanic/Remote legs of a ﬂight using the GNC 420. For further details, please refer to Sections 10.3 and 12.

MSG Key again.

1-8

GNC 420/420A Pilot’s Guide and Reference

SECTION 1

INTRODUCTION

Selecting COM Frequencies

While the GNC 420 is acquiring a position, take a minute to dial in the active and standby frequencies to be used for the ﬁrst phase of the ﬂight. The GNC 420’s display (Figure 1-12) is divided into separate windows (or screen areas), including a COM Window, data ﬁeld (distance), and the GPS Window (the right side of the display).

COM Window

Active Frequency

Standby Frequency

Data Field

Figure 1-12 Standby Frequency 135.325 MHz

GPS Window

Changing the standby communication frequency:

Turn the large

left knob to select the MHz,

and the small left knob to select the kHz of the desired frequency.

Placing the standby communication frequency in the active ﬁeld:

Press the COM Flip-ﬂop Key (Figure 1-13).

Figure 1-13 Active Frequency 135.325 MHz

After entering the active frequency, follow the preceding

steps to enter the standby frequency.

GNC 420/420A Pilot’s Guide and Reference

1-9

SECTION 1

INTRODUCTION

Page Groups

NAV Group WPT Group AUX Group NRST Group

see Section 3 see Section 7 see Section 9 see Section 8

Table 1-1 Page Groups

The bottom right corner of the screen (Figure 1-14) indicates which page group (Table 1-1) is currently being displayed (NAV, WPT, AUX, or NRST), the number of pages available within that group (indicated by square icons), and the placement of the current page within that group (indicated by a highlighted square icon).

In addition to the NAV Page Group, additional page groups are available for waypoint information (WPT), auxiliary (AUX) functions such as ﬂight planning or unit settings, and listings for nearest (NRST) airports or other facilities.

NOTE: The NRST Page Group may be accessed

by using the large right knob as described in the preceding procedure or by pressing the NRST Key.

NAV Pages

There are seven pages available under the NAV Page

Group*:

• Default NAV Page

• Map Page

• TERRAIN Page (if conﬁgured)

• NAV/COM Page

• Position Page

• Satellite Status Page

• Vertical Navigation Page

The Default NAV Page, the Map Page, and the NAV/

COM Page are used for most of the in-ﬂight navigation.

1-10

Position of

Current Page

within Current

Current Page Group

Figure 1-14 Current Page and Page Group

Number of Pages in

Current Page Group

Page Group

Selecting the desired page group and page:

1) Turn the large right knob until a page from the

desired page group is displayed (Figure 1-14).

2) Turn the small right knob until the desired page

is displayed (Figure 1-14).

GNC 420/420A Pilot’s Guide and Reference

NOTE: *The NAV Page Group may have eight

or nine NAV pages available when the GNC 420 installation includes connection to trafﬁc and/or weather information sources. See Section 11 of this manual for more information.

Selecting the NAV Page Group and display the Default NAV Page:

Press and hold the

CLR Key.

Selecting the desired NAV Page:

Turn the small right knob until the desired

page is displayed.

SECTION 1

INTRODUCTION

Map Page

After the GNC 420 acquires satellites and computes a position, the Map Page (Figure 1-15) appears automatically.

Map Display

Map Range

Present Position

Figure 1-15 Map Page

The Map Page displays the present position (using an airplane symbol) relative to nearby airports, VORs, NDBs, intersections, user waypoints, and airspace boundaries. The route is displayed as a solid line.

Data ﬁelds for destination waypoint (WPT), distance to waypoint (DIS), desired track (DTK), and ground speed (GS) appear on the right-hand side of the display. These ﬁelds are user selectable (Section 3.4, Selecting Desired On-screen Data) to allow the pilot to conﬁgure the unit. Available settings include: altitude, bearing, enroute safe altitude, estimated time of arrival, minimum safe altitude, and ground track.

A Map Setup Page is provided to designate the maximum range at which each map feature appears. These settings provide an automatic decluttering of the map (based upon preferences) while adjusting the range. See Section 12.3 for deﬁnitions of these navigation terms.

While viewing the Map Page, the pilot can quickly declutter and remove many of the background map details by pressing the CLR Key (repeatedly) until the desired detail is depicted.

Desired Track

Data Fields

To change the map range, press the up arrow (to zoom out) or the down arrow (to zoom in) of the RNG (map range) Key. The current map range is depicted in the lower left corner of the Map Display.

Direct-to Navigation

The GNC 420 can use direct point-to-point navigation to provide guidance from takeoff to touchdown, even in the IFR environment. Once a destination is selected, the unit provides speed, course, and distance data based upon a direct course from the present position to the destination. A destination can be selected from any page with the Direct-to Key.

Selecting a direct-to destination:

1) Press the Direct-to Key. The Select Direct-to

Waypoint Page appears with the destination ﬁeld highlighted.

2) Turn the small letter of the destination waypoint identiﬁer. The destination waypoint may be an airport, VOR, NDB, intersection, or user waypoint, as long as it is in the database or stored in memory as a user waypoint.

3) Turn the large the cursor to the next character position.

4) Repeat steps 2 and 3 to spell out the rest of the waypoint identiﬁer (Figure 1-16).

Figure 1-16 Direct-to Waypoint Page

right knob to enter the ﬁrst

right knob to the right to move

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5) Press the ENT Key to conﬁrm the identiﬁer. The

‘Activate?’ function ﬁeld is highlighted (Figure 1-17).

Figure 1-17 ‘Activate?’ Highlighted

6) Press the ENT Key to activate a direct-to course

to the selected destination.

Once a direct-to destination is selected, press and hold

the CLR Key to display the Default NAV Page.

Default NAV Page

During most ﬂights, the Default NAV Page, the Map Page, and the NAV/COM Page are the primary pages used for navigation.

Selecting the Default NAV Page:

Press and hold the

Active Leg of

Flight Plan

TO/FROM Flag Course Deviation

CLR Key (Figure 1-18).

Indicator (CDI)

The Default NAV Page displays a graphic course deviation indicator (CDI), the active leg of the ﬂight plan (as deﬁned by the current ‘from’ and ‘to’ waypoints), and six user-selectable data ﬁelds. The default settings for these ﬁelds are distance to waypoint (DIS), desired track (DTK), bearing to waypoint (BRG), ground speed (GS), ground track (TRK), and estimated time enroute (ETE). See Section 12.3 for deﬁnitions of these navigation terms.

Changing the data ﬁelds:

1) From the Default NAV page, press the MENU

Key and select ‘Change Fields?’ (Figure 1-19).

Figure 1-19 Default NAV Page Menu

2) Turn the large right knob to select the data

ﬁeld to be changed.

3) Turn the small

right knob to display a list of

data options (Figure 1-20).

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Figure 1-18 Default NAV Page

GNC 420/420A Pilot’s Guide and Reference

User-selectable

Data Fields

Figure 1-20 ‘Select Field Type’ Window

4) Press the ENT Key to select the desired data

item and return to the Default NAV Page.

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INTRODUCTION

NAV COM Page

From the Default NAV Page, simply turn the small right knob until the NAV/COM Page (Figure 1-21) is displayed.

Departure, Enroute, or

Arrival Airport

Frequency Type

Figure 1-21 NAV/COM Page

The NAV/COM Page displays the available frequencies (communications and navigation) for the departure airport, any enroute airports which are included in the ﬂight plan, and the ﬁnal destination airport. When using the directto function, frequencies are listed for the airport nearest to the starting position and the destination airport.

Displaying the frequency list for the desired ﬂight plan or direct-to airport:

Frequency List

A frequency listed on the NAV/COM Page can be quickly transferred to the standby ﬁeld of the COM Window (NAV frequencies are shown for reference only). This time-saving process prevents having to ‘re-key’ a frequency already displayed elsewhere on the screen.

Selecting a communication frequency:

1) Press the small right knob to activate the

cursor in the GPS Window.

2) Turn the large

right knob to select the desired

frequency from the list.

3) Press the ENT Key to transfer the selected

frequency to the standby ﬁeld in the COM Window. COM frequencies automatically go to the standby ﬁeld of the COM Window.

4) To activate the selected frequency, press the

COM Flip-ﬂop Key.

Displaying frequencies for a different airport along the ﬂight plan.

1) Press the small right knob to highlight the

airport identiﬁer ﬁeld.

2) Turn the small

right knob to display the list of

airports within the ﬂight plan (Figure 1-22).

1) Press the small right knob to activate the

cursor on the airport identiﬁer ﬁeld (in the GPS Window).

2) Turn the small

right knob to display the list

of airports (departure, arrival, and enroute) for the ﬂight plan or direct-to. Continue to turn the small right knob until the desired airport is selected.

3) Press the

ENT Key to display the frequency list

for the selected airport.

GNC 420/420A Pilot’s Guide and Reference

Figure 1-22 Airport Window

3) Continue turning the small right knob to select the desired airport and press the ENT Key.

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IFR Procedures

Once the direct-to or ﬂight plan is conﬁrmed, the whole range of instrument procedures is available to the pilot. Departures (SIDs), arrivals (STARs), and non-precision and precision approaches are stored within the NavData Card and are available using the

Displaying the Procedures Page:

Press the

PROC Key (Figure 1-23).

Figure 1-23 Procedures Page

The steps required to select and activate an approach, departure, or arrival are identical. This introductory section shows examples of the steps required to select an approach, but the same process also applies to departures and arrivals.

Selecting an approach, departure, or arrival:

1) Turn the large

right knob to select the desired

option (‘Select Approach?’, ‘Select Arrival?’, or ‘Select Departure?’) from the Procedures Page.

PROC (procedures) Key.

4) For approaches, a window appears (Figure 1-24) to select the desired initial approach ﬁx (IAF) or provide a ‘vectors’ option to select just the ﬁnal course segment of the approach. Turn the small right knob to select the desired option and press the

ENT Key. (The ‘vectors’

option extends the ﬁnal inbound course beyond the ﬁnal approach ﬁx, allowing the pilot to intercept the ﬁnal course segment beyond its normal limits.)

Figure 1-24 Approach Window

5) For departures and arrivals, a window appears to select the desired transition. Turn the small right knob to select the desired option and press the ENT Key.

In the ﬂight plan or direct-to, the departure or arrival airport is replaced with the sequence of waypoints contained within the selected procedure.

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2) Press the ENT Key to display a list of

available procedures for the arrival (when using approaches or STARs) or departure (when using SIDs) airport.

3) Turn the small right knob to select the desired procedure and press the ENT Key.

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Nearest (NRST) Pages

The NRST Page Group provides detailed information on the nine nearest airports, VORs, NDBs, intersections, and user-created waypoints within 200 nm of the current position. In addition, pages are also provided to display the ﬁve nearest center (ARTCC/FIR) and Flight Service Station (FSS) points of communication, plus alert the pilot to any nearby special-use or controlled airspaces.

There are eight pages available in the NRST group:

• Nearest Airport Page

• Nearest NDB Page

• Nearest User Waypoint Page

• Nearest FSS Page

• Nearest Intersection Page

• Nearest VOR Page

• Nearest ARTCC Page

• Nearest Airspace Page

The communication frequencies and information may both be examined directly from the Nearest Airport Page. As discussed earlier for the NAV/ COM Page, the pilot may also place any displayed frequency into the standby COM ﬁeld by highlighting the frequency with the cursor and pressing the ENT Key.

runway

Displaying the NRST pages:

1) Press the NRST Key to select the Nearest

Airport Page (Figure 1-25).

2) Turn the small right knob to select the desired

NRST Page.

Displaying a list of nearby airports:

1) Press the NRST Key to select the Nearest

Airport Page (Figure 1-25).

Figure 1-25 Nearest Airport Page

2) To scroll through the list, press the small right knob, then turn the large right knob (Figure 1-26).

Figure 1-26 Scrolling the Nearest Airport List

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Viewing additional information for a nearby airport:

1) Press the small right knob to activate the

cursor.

2) Turn the large

right knob to select the desired

airport from the list.

3) Press the

ENT Key to display waypoint (WPT)

information pages for the selected airport (Figure 1-27).

Figure 1-27 Airport Location Page

4) To display runway and frequency information,

press the small right knob to remove the cursor and turn the small right knob to display the desired information page.

Selecting a nearby airport as a direct-to destination from the Nearest Airport Page:

1) Press the small right knob to activate the cursor.

2) Turn the large

right knob to select the desired

airport from the list.

3) Press the Direct-to Key.

4) Press the

5) Press the

ENT Key.

ENT Key (again) to navigate to the

nearby airport.

Selecting a nearby airport as a direct-to destination from an Airport Information Page:

1) Press the Direct-to Key.

2) Press the

ENT Key (Figure 1-28).

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The Nearest Airport Page may be used in conjunction with the Direct-to Key to quickly set a course to a nearby facility in an in-ﬂight emergency. Selecting a nearby airport as a direct-to destination overrides the ﬂight plan or cancels a previously selected direct-to destination. (The pilot will still have the option of returning to the ﬂight plan by cancelling the direct-to; see Section 4.1, Cancelling Direct-to Navigation.)

GNC 420/420A Pilot’s Guide and Reference

Figure 1-28 ‘Activate?’ Highlighted

3) Press the ENT Key again to navigate to the

nearby airport.

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Nearest (NRST) Airspace Page

The last page in the NRST Page Group, the Nearest Airspace Page (Figure 1-29), provides information for up to nine controlled or special-use airspaces near or in the ﬂight path. Airspace information appears on this page based on the same criteria used for airspace alert messages:

• If the projected course will take the aircraft inside an airspace within the next ten minutes, the message ‘Airspace ahead -- less than 10 minutes’ appears.

• If the aircraft is within 2 nm of an airspace and the current course will take the aircraft inside, the message ‘Airspace near and ahead’ appears.

• If the aircraft is within 2 nm of an airspace and the current course will not take the aircraft inside, the message ‘Near airspace less than 2nm’ appears.

• If the aircraft has entered an airspace, the message ‘Inside airspace’ appears.

By default, airspace alert messages are turned off. When turned on, the message (MSG) annunciator located directly above the MSG Key ﬂashes to alert the pilot to the airspace message. See Section 9.4, Setup 1 Page: Airspace Alarms for information on enabling airspace alert messages.

Viewing an airspace alert message:

1) Press the MSG Key. The Messages Page appears

with the alert message (Figure 1-30).

Figure 1-30 Message Page

2) Press the MSG Key again to return to the

previous display.

Figure 1-29 Nearest Airspace Page

GNC 420/420A Pilot’s Guide and Reference

Note that the airspace alerts are based upon threedimensional data (latitude, longitude, and altitude) to avoid nuisance alerts. The alert boundaries for controlled airspace are also sectorized to provide complete information on any nearby airspace. Additional information about a nearby airspace (such as controlling agency, frequency, and ﬂoor/ceiling limits) is available from the Nearest Airspace Page (Section 8.9).

Viewing additional airspace information:

1) Press the small right knob to activate the

cursor.

2) Turn the large

right knob to select the desired

airspace from the list.

3) Press the ENT Key to view the airspace

information.

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Flight Plans (FPL)

The GNC 420 lets the pilot create up to 20 ﬂight plans, with up to 31 waypoints in each ﬂight plan. Flight plans are created, edited, and activated using the FPL Key. The FPL Page Group includes two pages: the Active Flight Plan Page and the Flight Plan Catalog Page (Figures 1-31 and 1-32). The Active Flight Plan Page provides information and editing features for the ﬂight plan currently in use (referred to as ‘ﬂight plan 00’). The Flight Plan Catalog Page serves as the main page for creating new ﬂight plans, as well as editing or activating previously created ﬂight plans.

Figure 1-31 Active Flight Plan Page

Since using ﬂight plans is arguably one of the more complex features of the GNC 420, it will only be discussed brieﬂy here, with focus on creating a new ﬂight plan and activating it to use for navigation. After reading through this brief introduction, answers to additional questions about ﬂight plans can be found in Section 5, Flight Plans.

Creating a new ﬂight plan:

1) Press the

2) Turn the small

FPL Key.

right knob to select the Flight

Plan Catalog Page.

3) Press the

MENU Key to display the Flight Plan

Catalog Page Menu (Figure 1-33).

Figure 1-33 Flight Plan Catalog Page Menu

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Figure 1-32 Flight Plan Catalog Page

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4) Turn the large right knob to select ‘Create New Flight Plan?’ and press the ENT Key.

5) The cursor appears on the ﬁrst waypoint identiﬁer ﬁeld (located directly below ‘WAYPOINT’). Use the large and small

right knobs to enter the

identiﬁer of the ﬁrst waypoint in the ﬂight plan. (The small knob is used to select the desired letter or number and the large knob is used to move to the next character space.)

6) Press the ENT Key once the identiﬁer has been selected. The cursor moves to the next blank waypoint identiﬁer ﬁeld.

7) Repeat steps 5 and 6 until all waypoints for the ﬂight plan have been entered (Figure 1-34).

Figure 1-34 Enter Flight Plan Waypoints

Once the ﬂight plan is created, it may be activated from the Flight Plan Catalog Page Menu. Activating the ﬂight plan places it into ‘ﬂight plan 00’ (a copy of it still resides in the original catalog location) and replaces any ﬂight plan which currently exists in ‘ﬂight plan 00’.

Activating the new ﬂight plan:

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1) Press the

MENU Key to display the Flight Plan

Catalog Page Menu.

2) Turn the small

right knob to select ‘Activate

Flight Plan?’ (Figure 1-35) and press the ENT Key.

Figure 1-35 Flight Plan Catalog Page Menu

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SECTION 2

COM

SECTION 2: COM

2.1 COMMUNICATING USING THE GNC 420

The GNC 420 features a digitally-tuned VHF COM radio that provides a seamless transition from communication to navigation, bringing the two most important functions in ﬂying together in one panel-mounted unit. The GNC 420’s COM radio operates in the aviation voice band, from

118.000 to 136.975 MHz, in 25 kHz steps (default). For European operations, a COM radio conﬁguration to allow for 8.33 kHz steps is also provided (Section 9.5, Setup 2 Page: COM Conﬁguration).

Volume

COM radio volume is adjusted using the COM Power/ Volume Knob. Turn the COM Power/Volume Knob

clockwise to increase volume, or counterclockwise to decrease volume.

Squelch

The COM radio features an automatic squelch, providing maximum sensitivity to weaker signals while rejecting many localized noise sources. The pilot may wish to override this automatic squelch function when listening to a distant station or when setting the desired volume level. The COM Power/Volume Knob allows the pilot to disable the automatic squelch and keep the COM audio open continuously.

COM Window and Tuning

Communication frequencies are selected with the tuning cursor in the standby COM frequency ﬁeld (Figure 2-1), using the small and large left knobs to tune the desired frequency. The standby frequency always appears below the active frequency. The active frequency is the frequency currently in use for transmit and receive operations.

Standby COM Frequency Field

‘RX’ Receive Indication

Figure 2-1 ‘RX’ Receive Indication

A frequency may also be quickly selected from the database by simply highlighting the desired frequency on any of the main pages and pressing the ENT Key. This process is referred to as auto-tuning. Once a frequency is selected in the standby ﬁeld, it may be transferred to the active frequency by pressing the COM Flip-ﬂop Key.

Overriding the automatic squelch:

1) Press the COM Power/Volume Knob

momentarily.

2) Press the COM Power/Volume Knob again

to return to automatic squelch operation.

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COM

While receiving a station, an ‘RX’ indication (Figure 2-1) appears in the upper right corner of the COM Window to the immediate right of ‘COM’. A ‘TX’ indication appears at this location when transmitting (Figure 2-2).

‘TX’ Transmit Indication

Figure 2-2 ‘TX’ Transmit Indication

Selecting a COM frequency:

1) Turn the large

left knob to select the desired

megahertz (MHz) value (Figure 2-3). For example, the ‘135’ portion of the frequency ‘135.325’.

2) Turn the small left knob to select the desired

kilohertz (kHz) value. For example, the ‘.325’ portion of the frequency ‘135.325’.

NOTE: The active frequency cannot be accessed

directly, only the standby frequency is highlighted by the tuning cursor.

Making the standby frequency the active frequency:

Press the COM Flip-ﬂop Key (Figure 2-4).

Figure 2-4 Active Frequency of 135.325

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Figure 2-3 Standby Frequency of 135.325

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