Garmin 55 AVD User manual

GPS 55AVD
Personal NavigatorTM
OWNER'S MANUAL

© 1992 GARMIN, 9875 Widmer Road, Lenexa, KS 66215
Printed in Taiwan.
All rights reserved. No part of this manual may be reproduced or transmitted
in any form or by any means, electronic or mechanical, including photocopying
and recording, for any purpose without the express written permission of
GARMIN.
Information in this document is subject to change without notice. GARMIN
reserves the right to change or improve their products and to make changes
in the content without obligation to notify any person or organization of such
changes or improvements.
October, 1992 190-00030-00 Rev. D

PREFACE
GARMIN thanks you for selecting our high performance, full featured
Personal NavigatorTM. The GPS 55 AVD represents our continued
commitment to provide you with a portable aviation unit that is versatile,
extremely accurate, and easy to use. We are confident you will enjoy using
your unit for many years to come.
The GPS 55 AVD's rugged construction and quality components offer the
reliability demanded by the harshest operating environments. When not
being used in an aircraft, it may be removed for use in marine and land
vehicles, as well as for hunting and hiking. The unit may be operated portably
using its own battery pack, or it may use a 5-40 volt DC external power source
for fixed mounted applications. You can even use a 115- or 230-volt battery
charger for planning trips at home.
This manual and accompanying quick reference guide provide complete
information on safely operating the GPS 55 AVD to its full potential. Two
exciting practice trips have been planned for you to practice your navigation
skills using the built-in simulator. Afterwards, try a trip of your own to realize
the value of the GPS 55 AVD as your Personal NavigatorTM. If you have any
questions or comments, our Customer Support Department is eager to serve
you. GARMIN is fully committed to your satisfaction as a customer.
GARMIN International, Inc.
9875 Widmer Road
Lenexa, KS 66215
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ii
CAUTION
The GPS system is operated by the government of the United States which
is solely responsible for its accuracy and maintenance. The system is under
development and is subject to changes which could affect the accuracy and
performance of all GPS equipment. Although the GPS 55 AVD is a precision
electronic NAVigation AID (NAVAID), any NAVAID can be misused or
misinterpreted, and therefore become unsafe. Use the GPS 55 AVD at your
own risk. To reduce the risk, carefully review and understand all aspects of
this Owner's Manual and thoroughly practice operation using the simulator
mode prior to actual use. When in actual use, carefully compare indications
from the GPS 55 AVD to all available navigation sources including the
information from other NAVAIDs, visual sightings, charts, etc. For safety,
always resolve any discrepancies before continuing navigation.
The Jeppesen database incorporated in the GPS 55 AVD must be updated
regularly in order to ensure that its information is current. GARMIN issues
an update approximately every 28 days. Contact GARMIN or your local
GARMIN aviation dealer for more information on GPS 55 AVD database
updates. Pilots using an out-of-date database do so entirely at their own risk.
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.

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TABLE OF CONTENTS
CHAPTER PAGE
BASIC FEATURES
1 INTRODUCING THE GARMIN GPS 55 AVD 1-1
1.1 Capabilities 1-1
1.2 Aviation Database 1-2
1.3 Operations 1-2
2 GETTING STARTED 2-1
2.1 Front Panel 2-1
2.2 Banners 2-1
2.3 Cursor and Fields 2-3
2.4 Keypad Operation 2-3
2.5 Entering Data 2-5
2.6 Viewing Messages 2-5
2.7 Operating Modes 2-6
3 BASIC OPERATION 3-1
3.1 Power On 3-1
3.2 Satellite Status 3-2
3.3 Present Position 3-3
3.4 AutoStoreTM 3-4
3.5 CDI and Navigation Summary 3-5
3.6 Waypoints 3-6
3.7 Nearest Waypoints 3-9
3.8 Navigate to a Waypoint 3-10
3.9 Proximity Alarm Waypoints 3-11
3.10 Sample Trip 3-12
4 UNIT CUSTOMIZATION 4-1
4.1 Setup Menu 4-1
4.2 Operating Mode 4-2
4.3 User Selectable Alarms 4-2
4.4 Backlighting Timeout 4-3
4.5 Audio Settings 4-4
4.6 Navigation Units 4-4
4.7 CDI Scale 4-5
4.8 Magnetic Variation 4-5
4.9 Filter Settings 4-6
4.10 Output 4-7

iv
4.11 Map Datum 4-7
ADVANCED FEATURES
5 NAVIGATION PLANNING 5-1
5.1 Navigation Menu 5-1
5.2 Date and Time 5-1
5.3 Event Timer 5-2
5.4 Trip Planning 5-4
5.5 Sunrise/Sunset 5-4
5.6 Alarm Clock 5-5
6 ROUTES 6-1
6.1 Navigating Using Routes 6-1
6.2 Route Catalog 6-2
6.3 Editing Routes 6-3
6.4 Activating Routes 6-5
6.5 Building Routes Using AutoStoreTM 6-7
7 SAMPLE SIMULATED TRIP 7-1
APPENDICES
A MESSAGES A-1
B NAVIGATION TERMS B-1
B.1 Definitions B-1
B.2 Course To Steer (CTS) B-3
C INSTALLATION AND MAINTENANCE C-1
C.1 Specifications C-1
C.2 Electrical Wiring C-3
C.3 Surface Mount Installation C-4
C.4 Portable Antenna Installation C-7
C.5 Battery Pack Operation C-8
C.6 Maintenance C-9
C.7 Customer Support C-9
D MAP DATUMS D-1
E ABBREVIATIONS FOR DATABASE REGIONS E-1
F AIRPORT IDENTIFIERS PREFIX CODES F-1
G INDEX G-1

1-1
CHAPTER 1
INTRODUCING THE GARMIN GPS 55 AVD
1.1 CAPABILITIES
The GPS 55 AVD provides a host of powerful capabilities which were
previously found only in much larger systems:
·Performance: State-of-the-art MultiTracTM receiver tracks up to eight
satellites while providing high receiver sensitivity, fast first fix, and
continuous navigation updates.
·Portability: Goes where you go - on land, sea, or in the air. The built-
in simulator allows you to plan your next trip or hone your navigation
skills at home or in your office.
·Navigation: Illuminated keypad and display provide the navigation
information you need at a glance. Store up to 250 alphanumeric
waypoints and 10 reversible routes. The GOTO function sets an
instantaneous course to the waypoint of your choice. The AutoStoreTM
function helps you build routes as you go. A flashing Message
Annunciator and an audible message tone keep you fully informed of
your navigation status.
·Personalized: Configure your unit the way you like by selecting
nautical units, Course Deviation Indicator (CDI) sensitivity, keypad
and display features, map datums, and interface options.
· Low Power Consumption: Battery Saver operation, which draws
less than 1.1 watts, provides up to ten hours of continuous operation
with four AA size alkaline batteries.
·Trip Planning: Analyze distance and time requirements for your trip.
Compute the time of sunrise and sunset at your destination.
·Alarms: An alarm clock and timer allow the GPS 55 AVD to watch the
clock for you. Arrival, anchor drag, CDI, and proximity alerts help you
safely navigate your craft.
·Interfaces: Interface with graphics plotters as well as marine autopilots.
We encourage you to read through this manual and experiment using the
built-in simulator. This will help you quickly master the power of the GPS 55
AVD.

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1.2 AVIATION DATABASE
The GPS 55 AVD features a built-in Jeppesen NavData®database providing
direct access to worldwide airport (with a runway of 1,000 feet or greater) and
VOR locations. Two versions of the internal database are available to cover
the entire world:
·Americas: Includes North, Central and South America.
·International: Includes everywhere except North, Central or South
America.
This database may be updated by a GARMIN authorized service center on
a one-time basis or every 28 days by subscription service. Contact GARMIN
or your local GARMIN aviation dealer for more information on GPS 55 AVD
database updates. (NOTE: Programmed routes and proximity alarms which
contain database waypoints that are deleted or moved more than 0.33 arc
minutes due to a database update will be deleted.)
1.3 OPERATIONS
You may use your GPS 55 AVD for both portable and fixed operations. The
unit may be operated from external AC power using a battery charger,
external 5-40 volt DC power using the power/data cable or cigarette lighter
adapter, or using a battery pack.
Handheld Operation:
For handheld operation, the GPS 55 AVD is powered by a AA battery pack
which should be filled with four high quality alkaline batteries commonly
found at retail stores. (A rechargeable nicad battery pack is also available.)
In order to track GPS satellites, the unit must be situated with the antenna
pointed straight up and should not be blocked by objects or people (signal
reception through thin fabric such as canvas may be adequate but degraded).
A lanyard is provided to prevent accidental dropping of your GPS 55 AVD.
(Connect the lanyard to the eyelet on the back of the unit.)
Aircraft Operation:
A mounting bracket is supplied for fixed mount installation in an aircraft.
Additionally, six feet cable with a suction cup and hardware is provided for
remote mounting of the portable antenna The unit may be operated using
aircraft power through the power/data cable or it may be operated using the
battery pack. While using aircraft power, you may wish to leave the battery

1-3
pack in the unit. In the event of aircraft power failure, the GPS 55 AVD will
automatically switch to battery power.
Marine/Land Operation:
A universal mount is available for swivel mount installation in a boat or land
vehicle. Additionally, a Marine/RV Remote Antenna is available for installations
which require an external antenna for an unobstructed view of the sky. This
weather-proof antenna includes 30 feet of low-loss antenna cable. The
remote antenna has been constructed to thread onto a standard 1" antenna
mount. Antenna mounts, commonly used to attach VHF radio antennas and
Loran-C couplers, are readily available from your local marine accessories
dealer.
A Magnetic Mount Antenna is also available for attaching a remote antenna
to a metallic surface. This weather-proof antenna includes 10 feet of low-loss
antenna cable. A cigarette lighter adapter cable may be used to power the
unit in vehicle applications.
In addition to supplying power to the unit, the power/data cable allows you to
interface your GPS 55 AVD with other electronic devices such as graphical
displays or marine autopilots.

2-1
CHAPTER 2
GETTING STARTED
2.1 FRONT PANEL
The front panel consists of a 20-key keypad and a LCD display which
includes three lines of information and various banners. Both the display and
keypad are illuminated for operating in darkness.
2.2 BANNERS
Information displayed on the LCD is commonly referred to as a “page”. A
page consists of alphanumeric information and banners. Banners, illustrated
below, are used to indicate the type of page, navigation units, and data
displayed (see Appendix B). They also indicate navigation fix type, satellite
tracking, and provide user prompting.

2-2

2-3
2.3 CURSOR AND FIELDS
Alphanumeric Field Cursor on
Confirmation Field
Numeric Field Cursor on Cyclic Field
The area of the page which is underlined is called the cursor. The cursor
may be moved to locations on the page calledfields which allow you to enter
data. You will encounter four types of fields.
·Numeric fields accept numbers. For example, you will enter a
waypoint's latitude in a numeric field.
·Alphanumeric fieldsaccept numbers as well as letters. For example,
you will enter a waypoint's name in an alphanumeric field.
·Cyclic fieldsallow you to select from one of several available options.
For example, you may select between DTK (desired track), BRG
(bearing to waypoint), or CTS (course to steer) using a cyclic field.
Cyclic fields are indicated on the display by the “MORE” banner.
·Confirmation fields allow you to indicate your approval. For example,
you will be asked to confirm that you want to delete a waypoint.
Confirmation fields always end with a “?” character.
2.4 KEYPAD OPERATION
The PWR/BRT key is a dual function key that controls unit power
and panel backlighting.
When the unit is on, pressing the PWR/BRT key will turn on the
panel backlighting. Pressing the PWR/BRT key again will turn off
the backlighting.
To turn the unit off, press and hold the PWR/BRT key for three
seconds until the display is blank.

2-4
Pressing the MSG/SET key allows you to view new messages
when the "MSG" banner is flashing. (See Section 2.6 and Appendix
A.) Pressing the MSG/SET key also selects the Setup Pages which
allow you to view satellite tracking status and customize the unit as
you like. (See Section 3.2 and Chapter 4.)
Pressing the GOTO key once allows you to initiate the GOTO
function, which will set an instantaneous course to any waypoint.
(See Section 3.8.)
Pressing the NAV key selects the Navigation Pages which allow
you to view navigation information and perform planning functions.
(See Sections 3.3 and 3.5 and Chapter 5.)
Pressing the WPT key selects the Waypoint Pages which allow you
to create, edit, delete, and rename waypoints. In addition, you may
view your nearest waypoints and set waypoint proximity alarms.
(See Sections 3.6, 3.7 and 3.9.)
Pressing the RTE key selects the Route Pages which allow you to
edit, review, activate, and delete routes. (See Chapter 6.)
Pressing either of the arrow keys allows you to move the
cursor, scroll through information lists, and enter letters of
the alphabet.
The alphanumeric keys allow you to enter letters and
numbers into the GPS 55.
If you want to enter a number in a numeric field, for instance
“1”, simply press the 1 key. If you want to enter a letter in
an alphanumeric field, for example “A”, press the 1 key to
display B, then press the left arrow key once to select “A”
(you may also press the right arrow key three times to
display the “A”).
Pressing the CLR/MORE key erases information in the cursor field.
If the cursor is over a cyclic field, pressing the CLR/MORE key will
toggle through several available options.
Pressing the ENT key completes the process of data entry. If the
cursor is over a confirmation field, pressing the ENT key indicates
your approval.

2-5
2.5 ENTERING DATA
To enter data you must first move the cursor under the desired field by
pressing the right or left arrow key.
To enter a number...
· Press the key that is labeled with the desired number. The numbers
will fill in from the left side of the field similar to a typewriter. You must
enter any leading zeros in the field. For example, if you wish to enter
“51” in a three space field, you must press the 0, 5, and 1 keys in that
order.
· Press the CLR key if you enter an incorrect number.
· Press the ENT key when you have filled all significant digits of the field
with numbers (trailing zeros are automatically filled in by the GPS 55).
To enter a letter...
· Press the key that is labeled with the desired letter.
· Press the right or left arrow key until the desired letter is displayed.
· Press the CLR key if you enter an incorrect letter.
· Press the ENT key when all the characters are entered.
The GPS 55 features a keypad feedback tone which will sound each time you
press a key. If you enter data which is not appropriate for the field, the
feedback tone will quickly sound three times indicating an error. The keypad
feedback tone can be turned off if you wish (see Section 4.5).
2.6 VIEWING MESSAGES
From time to time, the GPS 55 will use a message to tell you of conditions
that need your attention. When the GPS 55 has a new message for you, the
MSG banner will flash. When this occurs, press the MSG key to view new
message(s). Continue to press the MSG key until the page you were viewing
prior to pressing the MSG key is displayed.
While the MSG banner is flashing, the GPS 55 will also generate an audible
tone to alert you of the message (if your unit is connected to an external
alarm, it will also be activated). Messages that demand immediate attention
such as an arrival alarm generate a quick tone that will not stop until you view
the message. All other messages generate a slow tone that will cease after
15 seconds. The message tone may be turned off if you wish (see Section
4.5).

2-6
Important messages will remain on the Message Page after being viewed.
If this occurs, the MSG banner will be in view but will not flash (if no messages
exist, the MSG banner will not be visible). To review these messages, press
the MSG key until the “MESSAGES” title is displayed. Then, press the
MORE key until the “END MSGS” title is displayed.
Refer to Appendix A for a complete list of GPS 55 messages.
2.7 OPERATING MODES
Three modes are available which will allow you to operate your GPS 55 in the
way which best suits your needs (see Section 4.2).
Normal mode is most suitable for high dynamics applications. The GPS 55
will typically operate up to six hours on a single pack of batteries.
Battery Saver mode is suitable for most applications and will extend the
battery life to as much as ten hours.
Simulator mode allows you to simulate the operation of the GPS 55 while
at home or in your office. The simulator mode can be used while learning to
use your GPS 55 and is ideal for planning routes and entering waypoints.
Keep in mind that the GPS 55 is not tracking satellites in the simulator mode.
You should never attempt to use the simulator mode for actual navigation.
If you are using your GPS 55 for the first time, we encourage you to review
Chapter 3 which introduces the GPS 55's basic features. Additionally, you
may wish to review Chapter 4 on custom setups. Afterward, you may want
to read through the rest of this manual and make further use of the built-in
simulator to practice with the advanced features.

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CHAPTER 3
BASIC OPERATION
3.1 POWER ON
After you turn your GPS 55 on, it will conduct a series of self tests and display
the following notices: “VER x.xx”, “COPYRIGHT”, “1992”, and “GARMIN”.
Following completion of the tests, the Database Page, which indicates the
database version (Americas vs International), effective date, and expiration
date will now be displayed.
Database Version
Effective
Date
Expiration
Date
The GPS 55 will still function with a database which is out of date; however,
you must exercise extreme caution and always verify that the database
information is correct before use. (Warning: The accuracy of the database
information is assured only if the database is current. Pilots using an out-of-
date database do so entirely at their own risk.) After you press ENT to
approve the database, the GPS 55 will begin acquiring satellites. This
process is fully automatic and typically will take two minutes to obtain a
position fix.
Initially, the GPS 55 will display the “ACQ” banner; it will inform you when a
position fix is obtained by transitioning to either the “2D” or “3D” banner.
When four or more satellites with good geometry are available, the GPS 55
will automatically operate in the 3D mode in which latitude, longitude, and
altitude are computed. If only three satellites are available, the unit will
operate in 2D mode in which only latitude and longitude are computed. When
operating in the 2D mode, the unit will use the last computed altitude or your
last entered altitude (Section 3.3 describes how you may enter the altitude).
If less than three satellites with acceptable geometry are available, the “DR”
banner will be displayed.
Your GPS 55 will automatically update satellite orbital data as it operates. If
you have not operated your unit for a period of six months or longer, it will take
approximately 12.5 minutes to search the sky and collect new orbital data.
You will be informed when your unit is searching the sky with the message

3-2
“SRCH SKY”. Additionally, the “DATA” banner will be displayed. Once
satellite orbital data is collected, it will be stored in battery backed up memory.
This means the data will not be lost when you turn your GPS 55 off.
3.2 SATELLITE STATUS
Satellites EPE
Tracked/Visible
Satellite DOP
Identifier
Azimuth Elevation Signal Quality
SATELLITE STATUS PAGE
The Satellite Status Page may be displayed by pressing the SET key. This
page shows the number of satellites tracked and visible, dilution of precision
(DOP), and estimated position error (EPE). DOP is a measure of the satellite
geometry quality and hence the relative accuracy of your position (1 meaning
the best and 10 meaning poor). EPE, which is computed using the satellite
geometry (DOP), signal, and data quality, receiver tracking status and other
factors, is an overall measure of your position accuracy. DOP and EPE are
advisory information only.
The Satellite Status Page also shows the identifier (1-32), azimuth, elevation,
and signal quality of up to eight visible satellites. The azimuth is an angle from
000° to 359° which indicates the bearing from the present position to the
satellite, with 000° representing true north. The elevation is an angle from 00°
to 90° which indicates the height of the satellite above the horizon, where 00°
indicates the horizon and 90° indicates a satellite is directly overhead. The
azimuth and elevation are useful for determining whether a satellite signal is
blocked by buildings, mountains, or other obstructions. The signal quality is
a number from 1 through 9, with 9 indicating the strongest signal. If a satellite
is visible but not tracked, the signal quality will be blank.
The Satellite Status Page will automatically display each satellite’s information
for three seconds. You may also manually scroll through the list of visible
satellites.

3-3
To manually scroll through the visible satellite list...
· Use an arrow key to move the cursor under the satellite identifier.
· Press MORE to view each visible satellite’s information.
· Press ENT to remove the cursor and return to automatic mode.
3.3 PRESENT POSITION
Altitude
Latitude
Longitude
POSITION PAGE
The Position Page may be displayed by pressing the NAV key. This page
displays your latitude and longitude relative to the selected earth datum (see
Section 4.11). The altitude displayed is the elevation above mean sea level
(MSL); it is NOT equivalent to the altitude displayed on pressure altimeters
in aircraft and should not be used for vertical navigation. The displayed
altitude is typically less accurate than latitude/longitude due to the arrangement
of the orbiting satellites.
When the GPS 55 is performing 2D navigation, the last known altitude will be
used in the latitude/longitude computation. If your speed is over 65 knots, the
unit will ask you to update your altitude every ten minutes with the message
“NEED ALT.” If the altitude is not accurate within a few hundred feet, you
should manually enter your altitude.
To change the altitude...
· Press NAV to display the Position Page.
· Use an arrow key to move the cursor under the altitude.
· Enter the altitude. If your antenna is mounted on a high mast, make
sure you add the mast height. (Remember to complete the data entry
by pressing ENT.)
During initial satellite acquisition, the displayed position is the last computed
position stored in the GPS 55. If your position has moved more than 1000
nautical miles with the power off, you may wish to enter a more accurate initial
position to speed up the acquisition process. (You may also change the
position at any time when you are operating in simulator mode.)

3-4
To change the latitude/longitude...
· Use an arrow key to place the cursor under the latitude field.
· Check the hemispheric designation (“N” or “S”) of the latitude. If it is
correct, go to the next step. If it is incorrect, press the CLR key until
the correct hemispheric designation is displayed.
· Enter the latitude (remember to complete the data entry by pressing
ENT).
· Check the hemispheric designation (“E” or “W”) of the longitude. If it
is correct, go to the next step. If it is incorrect, press the CLR key until
the correct hemispheric designation is displayed.
· Enter the longitude (remember to complete the data entry by pressing
ENT).
3.4 AUTOSTORE
Waypoint
Name Storage Selection
Latitude
Longitude
AUTOSTORETM PAGE
The AutoStoreTM Page is displayed by pressing the ENT key while viewing
the Position Page. This page allows you to capture your position at the touch
of a button so that you may easily return later. Additionally, you may record
your navigation path by inserting the captured waypoints into a route (see
Section 6.5).
To capture your present position...
· Press NAV until the Position Page is displayed.
· Press ENT. The AutoStoreTM Page will be displayed with the default
waypoint name on line one. The waypoint name begins with a “+”
character followed by a 3-digit number, for example “+010”.
· If you wish to give the waypoint a name of your own, move the cursor
under the waypoint name and enter the name of your choice.