Garmin GTX 327 Manual

Mode A/C Transponder
pilot’s guide
GTX™ 327

© Copyright 1999 - 2002
GARMIN Ltd. or its subsidiaries
All Rights Reser ed
Except as expressly pro ided 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 prior written consent of GARMIN. GARMIN hereby grants permission to
download a single copy of this manual and of any re ision to this manual onto a hard dri e or
other electronic storage medium to be iewed and to print one copy of this manual or of any
re ision hereto, pro ided that such electronic or printed copy of this manual or re ision must
contain the complete text of this copyright notice and pro ided further that any unauthorized
commercial distribution of this manual or any re ision hereto is strictly prohibited.
This manual is written for software ersion 2.04, and is not suitable for earlier software er-
sions. Information in this document is subject to change without notice. Visit the GARMIN
web site (www.garmin.com) for current updates and supplemental information concerning the
operation of this and other GARMIN products.
Software License Agreement
BY USING THE GTX 327, YOU AGREE TO BE BOUND BY THE TERMS AND CONDITIONS
OF THE FOLLOWING SOFTWARE LICENSE AGREEMENT. PLEASE READ THIS AGREE-
MENT CAREFULLY.
GARMIN grants you a limited license to use the software embedded in this de ice (the “Soft-
ware”) in binary executable form in the normal operation of the product. Title, ownership
rights and intellectual property rights in and to the Software remain in GARMIN.
You acknowledge that the Software is the property of GARMIN and is protected under the
United States of America copyright laws and international copyright treaties. You further
acknowledge that the structure, organization and code of the Software are aluable trade
secrets of GARMIN and that the Software in source code form remains a aluable trade secret
of GARMIN. You agree not to decompile, disassemble, modify, re erse assemble, re erse
engineer or reduce to human readable form the Software or any part thereof or create any
deri ati e works based on the Software. You agree not to export or re-export the Software to
any country in iolation of the export control laws of the United States of America.
October 2002 Part Number 190-00187-00 Re . B Printed in USA

Limited Warranty
This GARMIN product is warranted to be free from defects in materials or workmanship for
one year 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 or labor, pro ided that the customer shall be
responsible for any transportation cost. This warranty does not co er failures due to abuse,
misuse, accident or unauthorized alteration 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 abo e limitations
may not apply to you.
GARMIN retains the exclusi e right to repair or replace the unit or software or 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 ser ice, contact your local GARMIN Authorized Ser ice Center. For
assistance in locating a Ser ice Center near you, call GARMIN Customer Ser ice at one of the
numbers shown below.
GARMIN International, Inc. GARMIN (Europe) Ltd.
1200 East 151st Street Unit 4, The Quadrangle, Abbey Park
Olathe, Kansas 66062, U.S.A. Industrial Estate, Romsey, SO51 9AQ, U.K.
Phone: [phone] Phone: [phone]
FAX: [phone] FAX: [phone]
NOTE: The GTX 327 owner accepts all responsibility for obtaining the proper
licensing before using the transponder.
NOTE: The co erage you can expect from the GTX 327 is limited to “line of
sight”. Low altitude or aircraft antenna shielding by the aircraft itself may
result in reduced range. Range can be impro ed by climbing to a higher alti-
tude. It may be possible to minimize antenna shielding by locating the antenna
where dead spots are only noticed during abnormal fl ight attitudes.
CAUTION: The GTX 327 should be turned off before starting or shutting down
aircraft engine(s).
)

Mode Selection Keys
OFF Powers off the GTX 327. Pressing STBY, ON or ALT
key powers on the transponder displaying the last acti e
identifi cation code.
STBY Selects the standby mode. When in standby mode,
the transponder will not reply to any interrogations.
ON Selects Mode A. In this mode, the transponder replies
to interrogations, as indicated by the Reply Symbol ( ).
Replies do not include altitude information.
ALT Selects Mode A and Mode C. In ALT mode, the transponder replies to identi-
fi cation and altitude interrogations as indicated by the Reply Symbol ( ). Replies to
altitude interrogations include the standard pressure altitude recei ed from an external
altitude source, which is not adjusted for barometric pressure. The ALT mode may be
selected in aircraft not equipped with an optional altitude encoder; howe er, the reply
signal will not include altitude information.
Any time the function ON or ALT is selected the transponder becomes an acti e part of
the Air Traffi c Control Radar Beacon System (ATCRBS). The transponder also responds to
interrogations from TCAS equipped aircraft.
Code Selection
Code selection is done with eight keys (0 – 7) pro iding 4,096 acti e identifi cation codes.
Pushing one of these keys begins the code selection sequence. The new code is not acti ated until
the fourth digit is entered. Pressing the CLR key mo es the cursor back to the pre ious digit.
Pressing the CLR key when the cursor is on the fi rst digit of the code, or pressing the CRSR key
during code entry, remo es the cursor and cancels data entry, restoring the pre ious code. You
may press the CLR key up to fi e seconds after code entry is complete to return the cursor to the
fourth digit. The numbers 8 and 9 are not used for code entry, only for entering a Count Down
time, contrast and display brightness, and data selection in the Confi guration Mode.
The GTX 327 transponder is powered on by pressing the STBY, ALT or ON keys, or by a remote avionics master switch
(if applicable) After power on, a start-up page is displayed while the unit performs a self test If the unit detects an
internal failure, the screen displays SELF TEST FAILED (See your GARMIN dealer for software upgrades )

Important Codes:
1200The VFR code for any altitude in the US (Refer to ICAO standards elsewhere)
7000The VFR code commonly used in Europe (Refer to ICAO standards)
7500Hijack code (Aircraft is subject to unlawful interference)
7600Loss of communications
7700Emergency
7777Military interceptor operations (Ne er squawk this code)
0000Military use (Not enterable)
A oid selecting code 7500 and all codes in the 7600-7777 range. These codes trigger
special indicators in automated facilities. An aircraft’s transponder code is used for ATC
tracking purposes, therefore exercise care when making routine code changes.
Keys for Other GT 327 Functions
IDENTPressing the IDENT key acti ates the Special Position Identifi ca-
tion (SPI) Pulse for 18 seconds, identifying your transponder return from
others on the air traffi c controller’s screen. The word ‘IDENT’ will appear in
the upper left corner of the display while the IDENT mode is acti e.
VFRSets the transponder code to the pre-programmed VFR code selected
in Confi guration Mode (this is set to 1200 at the factory). Pressing the VFR
key again restores the pre ious identifi cation code.
FUNCChanges the page shown on the right side of the display. Display
includes Pressure Altitude, Flight Time, Count Up and Count Down timers.
In Confi guration Mode, steps through the confi guration pages.
START/STOPS tarts and stops the Count Up, Count Down and Flight
timers. In Confi guration Mode, steps through confi guration pages in re erse.
CRSRInitiates starting time entry for the Count Down timer and cancels
transponder code entry. Selects changeable fi elds in Confi guration Mode.
CLRResets the Count Up, Count Down and Flight timers. Cancels the
pre ious keypress during code selection and Count Down entry. Returns
cursor to the fourth code digit within fi e seconds after entry. Used in
Confi guration Mode.
8Reduces Contrast and Display Brightness when the respecti e fi elds are
displayed and enters the number eight into the Count Down timer. Used
in Confi guration Mode.
9Increases Contrast and Display Brightness when the respecti e fi elds are
displayed and enters the number nine into the Count Down timer. Used in
Confi guration Mode.

PRESSURE ALT: Displays the altitude data supplied to the GTX 327 in feet,
hundreds of feet (i.e., fl ight le el), or meters, depending on confi guration.
FLIGHT TI E: Displays the Flight Time, controlled by the START/STOP
and CLR keys when Flight Timer is confi gured as manual. Under Auto-
mated Airborne Determination control, the timer begins when liftoff is
sensed.
COUNT UP TI ER: Controlled by START/STOP and CLR keys.
COUNT DOWN TI ER: Controlled by START/STOP, CLR, and CRSR
keys. The initial Count Down time is entered with the 0 – 9 keys.
CONTRAST: This page is only displayed if manual contrast mode is
selected in Confi guration Mode. Contrast is controlled by the 8 and 9 keys.
DISPLAY: This page is only displayed if manual backlighting mode is selected
in Confi guration Mode. Backlighting is controlled by the 8 and 9 keys.
GT 327 Confi guration Mode
The GTX 327’s confi guration is normally set at time of installation. To iew or change any
of the GTX 327 confi guration parameters, you must access the GTX 327 Confi guration Mode.
Use caution when changing confi guration. When in doubt, contact your authorized GARMIN
A iation Ser ice Center. Your GARMIN dealer can assist in confi guration changes. The Con-
fi guration Mode should not be used during fl ight.
To use the GTX 327 Confi guration Mode:
1. Press and hold the FUNC key while powering on the unit using the STBY, ON, or LT key
(or using an avionics master switch).
2. Press the FUNC key to sequence through the confi guration pages. Press the ST RT/STOP
key to sequence in reverse. Reverse sequence stops on the isplay Mode page.
3. Use the CRSR key to highlight selectable fi elds on each page.
4. When a fi eld is highlighted, use the 8 or 9 keys to select changeable fi elds or the 0 - 9
keys to enter numeric data.
5. Press the CRSR key to confi rm list selections.
Function Display

Altitude Trend Indicator
When the ‘PRESSURE ALT’ page is displayed, an arrow may be displayed to the right of
the altitude, indicating that the altitude is increasing or decreasing. One of two sizes of arrows
may be displayed depending on the rate of climb/descent. The sensiti ity of these arrows is set
using the GTX 327 Confi guration Mode ertical speed rate.
Timer Operation
To operate the Flight Timer:
1. Press the FUNC key until ‘FLIGHT TIME’ is displayed.
2. If the GTX 327 Flight Timer is confi gured as ACCUMULATE or CLEAR, the timer will begin
automatically when the unit senses that the aircraft has become airborne. The timer may
be reset to zero at every liftoff (CLEAR), continue accumulating time at liftoff (ACCUMU-
LATE) or may be controlled manually (MANUAL).
3. If desired, you may press ST RT/STOP to pause or restart the timer.
4. Press CLR to reset the timer to zero.
5. If the timer is confi gured to start automatically it will pause when the Automated Airborne
etermination senses that the aircraft is on the ground.
To operate the Count Up timer:
1. Press the FUNC key until ‘COUNT UP’ is displayed.
2. If necessary, press CLR to reset the Count Up timer to zero.
3. Press ST RT/STOP to count up.
4. Press ST RT/STOP again to pause the timer.
5. Press CLR to reset the timer to zero.
To operate the Count Down timer:
1. Press the FUNC key until ‘COUNT OWN’ is displayed.
2. Press CRSR and use the 0 - 9 keys to set the initial time. All digits must be entered (use
the 0 key to enter leading zeros).
3. Press ST RT/STOP to count down.
4. Press ST RT/STOP again to pause the timer.
5. When the Count own timer expires, the ‘COUNT OWN’ banner is replaced with a
fl ashing ‘EXPIRE ’, and the time begins counting up.
6. Press CLR to reset the timer to the initial time value.
Automatic ALT/STBY Mode Switching
If the GTX 327 is confi gured with Automated Airborne Determination, ALT mode
selection occurs when liftoff is sensed. When the aircraft is on the ground, the transponder
automatically selects and displays STBY. The transponder does not respond to ATCRBS inter-
rogations when STBY is annunciated. When a delay time is set in the Confi guration Mode, the
GTX 327 waits this additional length of time after landing before changing to STBY mode.

© 1999 - 2002 GARMIN Ltd. or its subsidiaries
GARMIN International, Inc.
1200 East 151st Street, Olathe, Kansas 66062, U.S.A.
GARMIN (Europe) Ltd.
Unit 5, The Quadrangle, Abbey Park Industrial Estate, Romsey, SO51 9AQ, U.K.
GARMIN Corporation
No. 68, Jangshu 2nd Road, Shijr, Taipei County, Taiwan
www.garmin.com
Part Number 190-00187-00 Re . B