ARTEX B406-4 Instruction Manual

Page 1 of 70
Feb 28/2019
570-5004 Rev. N
Initial Issue DEC 02/1999
ARTEX PRODUCTS / ACR ELECTRONICS, INC.
5757 Ravenswood Rd, Ft. Lauderdale, FL 33312
Cage Code: 18560
25-62-03
B406-4
Emergency Locator Transmitter
Description, Operation, Installation and Maintenance Manual
This manual includes data for the equipment that follows:
Component Part No. Model No.
Emergency Locator Transmitter 453-5004 B406-4

ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
B406-4 (453-5004)
Page 2 of 70
25-62-03
PROPRIETARY INFORMATION
This document contains proprietary information and such information may not be disclosed to others for any
purpose, nor used for manufacturing purposes without written permission from ACR Electronics.
Information in this manual is subject to change without notice. ACR Electronics makes no warranty, expressed
or implied, with regard to this manual, including but not limited to any implied warranties of merchantability,
fitness for a particular purpose, and non-infringement. In addition, ACR Electronics makes no warranty with
regard to the documentation or data contained herein. ACR Electronics is not liable in the event of incidentals,
special, consequential, or any other damages in connection with or arising from furnishing, performance, or use
of this manual.
Reproduction of this publication or any portion thereof by any means is prohibited. For further information
contact Sales, ACR Electronics, 5757 Ravenswood Rd, Fort Lauderdale, FL 33312. Telephone [phone].
AIRWORTHINESS LIMITATIONS
The Airworthiness limitations section is FAA approved and specifies inspections and other maintenance required
under 14 CFR§ 43.16 and 91.403, unless an alternative program has been approved.
IMPORTANT NOTICE
ACR Electronics will be responsible for full distribution and revisions of ICA’s (Instructions for Continued
Airworthiness). For inquiries regarding the content and currency of this manual, contact ACR Electronics, 5757
Ravenswood Rd, Fort Lauderdale, FL 33312. Telephone [phone].

ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
B406-4 (453-5004)
Page 3 of 70
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RECORD OF REVISIONS
REVISION
CHANGE
DATE
REVISION
CHANGE
DATE
-
RELEASE
Dec 02/1999
A
ECO 1418
Jun 22/2000
B
DCN 1641
Apr 11/2001
B
DCN 1747
Jul 19/2001
B
DCN 1965
Apr 04/2002
B
DCN 2115
Dec 10/2002
B
DCN 2356
Feb 11/2004
C
DCN 2968
Mar 20/2007
C
DCN 3174
Feb 26/2008
C
DCN 3282
Aug 25/2008
D
DCA W9414
Apr 06/2010
E
ECO 14756
Jul 28/2011
F
ECO 15177
Aug 27/2012
G
ECO 15330
Mar 1/2013
H
ECO 15410
Jun 20/2013
J
ECO 15510
Oct 14/2013
K
ECO 15830
Dec 01/2014
L
ECO 16361
May 11/2016
M
ECO 16887
Mar 30/2018
N
ECO 17024
Feb 28/2019

ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
B406-4 (453-5004)
Page 4 of 70
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SERVICE BULLETIN LIST
SERVICE
BULLETIN NO
ISSUE
DATE
SUBJECT
MANUAL
REV NO
MANUAL
REV DATE

ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
B406-4 (453-5004)
Page 5 of 70
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LIST OF EFFECTIVE PAGES
SUBJECT
PAGE
DATE
SUBJECT
PAGE
DATE
Title Page
1
Feb 28/19
Test and Fault Isolation (cont)
36
Oct 14/13
Notices
2
Oct 14/13
37
Oct 14/13
Record of Revisions
3
Feb 28/19
Removal
38
Oct 14/13
Service Bulletin List
4
Oct 14/13
39
Oct 14/13
List of Effective Pages
5
Feb 28/19
40
Oct 14/13
Table of Contents
6
Feb 28/19
Installation
41
Dec 01/14
7
Feb 28/19
42
Dec 01/14
8
Feb 28/19
43
Oct 14/13
List of Figures
9
Feb 28/19
44
Oct 14/13
Introduction
10
Oct 14/13
45
Oct 14/13
11
Oct 14/13
46
Oct 14/13
12
Oct 14/13
47
Oct 14/13
13
Oct 14/13
48
Oct 14/13
14
Oct 14/13
49
Oct 14/13
15
Oct 14/13
50
Oct 14/13
16
Oct 14/13
51
Oct 14/13
Description and Operation
17
Oct 14/13
52
Oct 14/13
18
Oct 14/13
53
Oct 14/13
19
Oct 14/13
54
Oct 14/13
20
Oct 14/13
55
Oct 14/13
21
Oct 14/13
56
Oct 14/13
22
Oct 14/13
57
Oct 14/13
23
Oct 14/13
58
Oct 14/13
24
Oct 14/13
59
Oct 14/13
25
Oct 14/13
60
Oct 14/13
Test and Fault Isolation
26
Oct 14/13
Appendix A
61
Oct 14/13
27
Oct 14/13
62
Oct 14/13
28
Oct 14/13
Illustrated Parts List
63
Oct 14/13
29
Feb 28/19
64
Oct 14/13
30
Oct 14/13
65
Oct 14/13
31
Oct 14/13
66
Oct 14/13
32
Oct 14/13
67
Oct 14/13
33
Oct 14/13
68
Oct 14/13
34
Oct 14/13
69
Oct 14/13
35
Oct 14/13
70
Feb 28/19

ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
B406-4 (453-5004)
Page 6 of 70
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TABLE OF CONTENTS
RECORD OF REVISIONS ............................................................................................................................3
SERVICE BULLETIN LIST ...........................................................................................................................4
LIST OF EFFECTIVE PAGES........................................................................................................................5
TABLE OF CONTENTS ...............................................................................................................................6
LIST OF FIGURES .....................................................................................................................................9
INTRODUCTION .....................................................................................................................................10
1. Manual Usage ..............................................................................................................................10
A. General ...............................................................................................................................10
B. Application .......................................................................................................................... 10
2. Model Description ........................................................................................................................11
A. B406-4 ................................................................................................................................11
3. Approvals ....................................................................................................................................11
A. B406-4 ................................................................................................................................11
B. Battery ................................................................................................................................ 11
C. RTCA DO-160D Compliance .................................................................................................. 11
4. Frequency Allocations...................................................................................................................13
A. Application .......................................................................................................................... 13
B. Discussion ........................................................................................................................... 13
5. List of Acronyms, Abbreviations, and Definitions ............................................................................14
6. References ..................................................................................................................................16
A. Regulatory Documents .........................................................................................................16
B. Other Documents................................................................................................................. 16
DESCRIPTION AND OPERATION ..............................................................................................................17
1. Description ..................................................................................................................................17
A. Functional Overview ............................................................................................................. 17
B. Components ........................................................................................................................18
2. Operation ....................................................................................................................................21
A. Operational Overview ...........................................................................................................21
B. Normal Operation ................................................................................................................22
C. Manual Activation................................................................................................................. 22
D. ELT Reset............................................................................................................................22
E. Functional Check.................................................................................................................. 22
3. Specifications...............................................................................................................................23
A. Environmental and Physical ..................................................................................................23
B. Electrical ............................................................................................................................. 24
C. Antennas.............................................................................................................................25
TEST AND FAULT ISOLATION .................................................................................................................. 26
1. Inspection and Test Regulatory Requirements ...............................................................................26
A. United States ....................................................................................................................... 26
B. Canada................................................................................................................................26
C. Other Countries ................................................................................................................... 26

ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
B406-4 (453-5004)
Page 7 of 70
25-62-03
2. Inspection and Test Procedures ....................................................................................................27
A. Checklist.............................................................................................................................. 27
B. Preparation..........................................................................................................................28
C. Coax Cables and Wiring Connections Inspection –Item 1.......................................................28
D. Mounting Tray and Hardware Inspection –Item 2 .................................................................28
E. Battery Pack Inspection –Item 3 ..........................................................................................28
F. G-Switch Functional Check –Item 4a .................................................................................... 29
G. G-Switch Functional Check (Helicopter Models Only)–Item 4b................................................29
H. Performance Testing Setup...................................................................................................30
I. 121.5 MHz Frequency Measurement –Item 5a ......................................................................31
J. Audio Modulation Check –Item 5b........................................................................................31
K. 121.5/243.0 MHz Power Output Measurement –Item 5c........................................................31
L. 406 MHz Frequency Measurement –Item 5d .........................................................................31
M. 406 MHz Power Output Measurement –Item 5e ....................................................................32
N. Current Draw Test –Item 5f.................................................................................................32
O. Digital Message Verification –Item 5g...................................................................................33
P. ELT Reset Check –Item 5h ..................................................................................................34
Q. Installed Transmitter Test –Item 6 .......................................................................................34
R. Antenna Test –Item 7 ......................................................................................................... 35
S. Inspection and Test Documentation –Item 8 ........................................................................35
3. Troubleshooting...........................................................................................................................36
A. Self-Test Error Troubleshooting Guidelines ............................................................................ 36
B. ELT Troubleshooting Guidelines ............................................................................................ 38
REMOVAL ............................................................................................................................................... 39
1. ELT .............................................................................................................................................39
A. ELT Removal ....................................................................................................................... 39
2. Battery ........................................................................................................................................40
A. Battery Pack Removal ..........................................................................................................40
3. Material or Equipment Return .......................................................................................................41
A. Shipment Information ..........................................................................................................41
B. Return Material Authorization................................................................................................41
INSTALLATION ....................................................................................................................................... 42
1. Regulatory Requirements and Guidelines .......................................................................................42
A. For US Registered aircraft: ...................................................................................................42
B. TSO C126, Paragraph D ....................................................................................................... 42
C. FAA..................................................................................................................................... 42
D. Canada................................................................................................................................43
E. Other Countries ................................................................................................................... 43
F. RTCA...................................................................................................................................43
2. Mounting Tray .............................................................................................................................44
A. Location .............................................................................................................................. 44
B. Installation .......................................................................................................................... 45
3. Antenna ......................................................................................................................................46
A. Selection .............................................................................................................................46
B. Location .............................................................................................................................. 46
C. Installation .......................................................................................................................... 46
4. Remote Switch Panel....................................................................................................................50
A. Location .............................................................................................................................. 50
B. Installation .......................................................................................................................... 50

ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
B406-4 (453-5004)
Page 8 of 70
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5. Buzzer.........................................................................................................................................51
A. Location .............................................................................................................................. 51
B. Installation .......................................................................................................................... 51
6. Wiring .........................................................................................................................................52
A. General Considerations and Recommendations ......................................................................52
B. Remote Switch Panel Harness Fabrication and Installation ...................................................... 52
C. Buzzer Wiring Fabrication ..................................................................................................... 55
D. ELT 12-Pin Receptacle Wiring Fabrication and Installation ......................................................55
E. Coax Cables Installation .......................................................................................................56
F. Antenna Connections ...........................................................................................................57
G. Airframe Ground Connections ............................................................................................... 57
H. Buzzer Connections ..............................................................................................................57
I. Remote Switch Panel Final Installation .................................................................................. 57
7. ELT Installation............................................................................................................................58
A. Installation and Test ............................................................................................................58
B. Harness ELT Receptacle Sealing............................................................................................59
C. Installation Documentation ...................................................................................................59
8. Battery Pack Installation...............................................................................................................60
A. Battery Reinstallation ...........................................................................................................60
B. New Battery Installation .......................................................................................................61
APPENDIX A –ELT REGISTRATION..........................................................................................................62
1. Background Information ...............................................................................................................62
A. Hex ID Code ........................................................................................................................ 62
B. Reason for Registration ........................................................................................................ 62
C. Registration Information Resources.......................................................................................62
2. Registration .................................................................................................................................63
A. Responsibility.......................................................................................................................63
B. Required Information ...........................................................................................................63
C. Where to Register ................................................................................................................63
ILLUSTRATED PARTS LIST ...................................................................................................................... 64
1. Introduction.................................................................................................................................64
A. Purpose............................................................................................................................... 64
B. IPL Usage Guide .................................................................................................................. 64
2. Manufacturer Name and Address ..................................................................................................64
A. Ordering Information ...........................................................................................................64
3. Explanation of Detailed Parts List Entries .......................................................................................65
A. Fig # & Item Column ...........................................................................................................65
B. Part # Column .....................................................................................................................65
C. Nomenclature Column ..........................................................................................................65
D. UPA (Units Per Assembly) Column......................................................................................... 66
4. Detailed Parts List ........................................................................................................................67

ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
B406-4 (453-5004)
Page 9 of 70
25-62-03
LIST OF FIGURES
Figure 1 B406-4 ELT and Mounting Frame Assembly ..........................................................................18
Figure 2 Remote Switch Panel Assembly Front View ...........................................................................18
Figure 3 Buzzer................................................................................................................................ 19
Figure 4 Battery Pack Assembly ........................................................................................................19
Figure 5 Antennas............................................................................................................................20
Figure 6 ELT Operational Flow Diagram.............................................................................................21
Figure 7 ELT Orthogonal Axes...........................................................................................................30
Figure 8 Performance Testing Equipment Setup .................................................................................31
Figure 9 Current Draw Test Setup .....................................................................................................33
Figure 10 Short and Long 406 MHz Message Examples.......................................................................34
Figure 11 ELT Removal Sequence .....................................................................................................39
Figure 12 Battery Pack Removal........................................................................................................40
Figure 13 B406-4 ELT Outline and Dimensions...................................................................................44
Figure 14 Typical Mounting Tray Installation......................................................................................45
Figure 15 Rod Antenna 110-320 and Blade Antenna 110-328-01 Outlines and Dimensions ...................47
Figure 16 Blade Antennas 110-333 and 110-337 Outlines and Dimensions...........................................48
Figure 17 Blade Antenna 110-337-11 Outline and Dimensions ............................................................49
Figure 18 Remote Switch Panel Assembly Outline and Dimensions ......................................................50
Figure 19 Buzzer Outline and Dimensions ..........................................................................................51
Figure 20 Remote Switch Panel Harness Wiring Diagram .................................................................... 53
Figure 21 Remote Switch Panel Harness Wiring at ELT End ................................................................56
Figure 22 ELT Installation Sequence..................................................................................................58
Figure 23 Battery Pack Installation ....................................................................................................60
Figure 24 Battery Pack Retaining Screw Tightening Pattern ................................................................ 61
Figure 25 B406-4 ELT Main Assembly and Installation ........................................................................67
Figure 26 Electrical Components .......................................................................................................69
Figure 27 Antennas ..........................................................................................................................70

ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
B406-4 (453-5004)
Page 10 of 70
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INTRODUCTION
TASK 25-62-03-990-801
1. Manual Usage
SUBTASK 25-62-03-990-001
A. General
1) This manual describes the operation, installation, and maintenance of the Model B406-4 emergency
locator transmitter (ELT). The information is provided to ensure initial and continued airworthiness.
Information presented in this manual is accurate at time of printing, but is subject to change. Refer to
the Artex products web site at www.acrartex.com for the latest information and any updates to this
manual.
2) Information on COSPAS-SARSAT emergency locator beacon registration requirements and procedures is
provided in Appendix A –ELT Registration on page 62.
3) Web links provided in this manual were accurate at time of printing but may be subject to change.
4) ACR Electronics reserves the right to add approved components to the ELT system; including, but not
limited to antennas, remote switch panels, and coaxial cables.
5) Regulatory references contained herein are generally confined to United States and Canadian
requirements and, in any case, should not be considered all encompassing. Consult your national
aviation authority for applicable requirements.
SUBTASK 25-62-03-990-002
B. Application
1) This manual constitutes supporting data/documentation for the B406-4 ELT, including:
a) Description and Operation
b) Test and Fault Isolation (includes inspection criteria)
c) Removal
d) Installation
e) Registration
f) Illustrated Parts List
2) In the United States, the B406-4 ELT must be installed and maintained in accordance with the
requirements herein and 14 CFR, FAR Parts 43, and 91; and other airworthiness requirements, as
applicable.
3) In Canada, the B406-4 ELT must be installed and maintained in accordance with the requirements
herein and Canadian Aviation Regulations (CAR), Part V, Paragraph 551.104 and other CAR
airworthiness requirements, as applicable.
4) B406-4 ELT installation and maintenance in all other countries must comply with the requirements
herein and applicable national airworthiness requirements.
5) The accessories (i.e., remote switch panel and antennas) addressed in this manual are the accessories
most commonly associated with the B406-4 ELT. Other options, such as a different remote switch panel
configuration or an ELT/NAV Interface -B, should be installed and maintained in accordance with the
written instructions specific to the accessory.
NOTE: Contact ACR Electronics for optional accessories approved for use with the B406-4 ELT.
6) To ensure proper operation, only parts listed in the Illustrated Parts List of this manual or those
recommended by ACR Electronics may be used as replacement parts for the B406-4 ELT.

ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
B406-4 (453-5004)
Page 11 of 70
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TASK 25-62-03-990-802
2. Model Description
SUBTASK 25-62-03-990-001
A. B406-4
1) The B406-4 is a type AF (Automatic Fixed) ELT, which transmits on 121.5, 243.0, and 406 MHz.
2) The ELT is enclosed within a multi-piece mounting frame consisting of a mounting tray assembly,
protective top cover assembly and mounting frame cap assembly.
3) When ordered as a system, an installation kit, cockpit remote switch panel, coax cables, audible buzzer,
and dual input antenna are provided.
TASK 25-62-03-990-803
3. Approvals
SUBTASK 25-62-03-990-001
A. B406-4
1) FAA TSO C126, Type AF
a) The conditions and tests required for TSO approval of this article are minimum performance
standards. It is the responsibility of those installing this article either on or within a specific type or
class of aircraft to determine that the aircraft installation conditions are within TSO standards. TSO
articles must have separate approval for installation in an aircraft. The article may be installed only
if performed under 14 CFR Part 43 or the applicable airworthiness requirements.
2) Transport Canada - Type Certificate Data Sheet AP-47 Issue 2
3) Industry Canada - Certification Number 1215873110AF
4) JTSO-2C126
5) COSPAS-SARSAT - Certificate No. 112 or 170
SUBTASK 25-62-03-990-002
B. Battery
CAUTION: LITHIUM BATTERY SAFETY CONCERNS INCLUDE THE POSSIBILITY OF FIRE, VENTING
VIOLENTLY, AND VENTING OF TOXIC GASES.
1) The lithium battery pack used on the B406-4 ELT is certified under TSO C142.
a) The conditions and tests required for TSO approval of this battery are minimum performance
standards. It is the responsibility of those desiring to install this battery in a specific type or class of
aircraft to determine that the aircraft installation conditions are within the TSO standards. The
battery may be installed only if further evaluation by applicant documents an acceptable installation
and is approved by the Administrator.
SUBTASK 25-62-03-990-003
C. RTCA DO-160D Compliance
1) DO-160D Environmental Categories: C1-BA204XRXXXXXZAZZ204BXXX
2) The DO-160D environmental categories breakdown is detailed in Table 1 on page 12.

ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
B406-4 (453-5004)
Page 12 of 70
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CATEGORY
SECTION
DESCRIPTION
C1
4.0
Temperature/Altitude
-
4.5.4
In-Flight Loss of Cooling
B
5.0
Temperature Variation
A
6.0
Humidity
204
7.0/8.0
Operational Shock and Crash Safety/Vibration
X
9.0
Explosion
R
10.0
Waterproofness
X
11.0
Fluids Susceptibility
X
12.0
Sand and Dust
X
13.0
Fungus
X
14.0
Salt Spray
X
15.0
Magnetic Effect
Z
16.0
Power Input
A
17.0
Voltage Spike
Z
18.0
Audio Frequency Susceptibility
Z
19.0
Induced Signal Susceptibility
204
20.0
Radio Frequency Susceptibility
B
21.0
Emission of RF Energy
X
22.0
Lightning
X
23.0
Lightning Direct Effects
X
24.0
Icing
Table 1 Environmental Categories Breakdown

ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
B406-4 (453-5004)
Page 13 of 70
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TASK 25-62-03-990-804
4. Frequency Allocations
SUBTASK 25-62-03-990-001
A. Application
1) This section addresses the 406.0-406.1 MHz transmitter window and the specific frequency band
allocations residing above 406.025 MHz, beginning with 406.028 MHz, which are assigned or reserved
within the 406.0-406.1 MHz distress frequency window.
SUBTASK 25-62-03-990-002
B. Discussion
1) The 406 MHz transmitter frequency of the B406-4 ELT was originally 406.025 MHz. In order to comply
with COSPAS-SARSAT frequency allocation requirements, changes to the 406 MHz frequency may occur
since the original release of this product.
2) While the original B406-4 ELTs covered by this manual transmit on 406.025 MHz, current B406-4 ELTs
may not. The product identification label on each ELT specifies the transmitting frequencies of the
individual ELT. The 406 MHz component may be 406.025, 406.028, 406.037 MHz, etc. Allocation of
frequencies, based on beacon population per specified frequency band, is controlled by
COSPAS-SARSAT.
3) The frequency references throughout this manual for the 406 MHz component should be considered the
baseline and the specific frequency indicated on the ELT product label should be substituted if it differs
from 406.025 MHz.

ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
B406-4 (453-5004)
Page 14 of 70
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TASK 25-62-03-990-805
5. List of Acronyms, Abbreviations, and Definitions
SUBTASK 25-62-03-990-001
Term Definition
AC Advisory Circular –A Federal Aviation Administration (USA) bulletin with special
information. For the purposes of this document, the acronym AC does not refer to
electrical alternating current.
AWG American Wire Gauge –An electrical wire diameter standard. Look for this
acronym in front of or following a wire size number.
BNC Connector A very common type of coax cable connector having a 50 impedance and used
for RF signal connections.
CAR Canadian Aviation Regulations –The rules and regulations governing the
manufacture, certification, operation, maintenance, and alteration of aircraft in
Canada.
CFR Code of Federal Regulations –The general and permanent rules published in the
Federal Register by the executive departments and agencies of the Federal
Government. Title 14, “Aeronautics and Space” contains the FARs.
Container The term “Container”, within the context of this document, refers to a device
designed to suppress RF signals, such that the broadcast of an ELT placed in the
container cannot reach the SAR satellite system.
COSPAS-SARSAT The international search and rescue consortium that governs the international
satellite-based search and rescue distress alert detection and information
distribution system. For a complete description go to the official web site for the
International COSPAS-SARSAT Program.
DER Designated Engineering Representative –An individual qualified and designated
by the FAA to approve, or recommend approval, of technical data to the FAA.
Drip Loop Extra wire length used to form a U-shaped bend in a wire or cable. Water or other
fluids will flow down to the bottom of the loop and drip off. Electrical connections
are made at the top of the loop.
ELT Emergency Locator Transmitter –ELTs are installed on aircraft and used to send
emergency signals to the SAR satellite system. The word “Beacon” is associated
with these devices.
EMI Electromagnetic Interference –An undesirable disturbance that affects an
electrical circuit due to either electromagnetic conduction or electromagnetic
radiation emitted from an external source. Also called radio frequency interference
or RFI.
Eurocae European Organization for Civil Aviation Equipment –EUROCAE documents are
widely referenced as a means of compliance to European Technical Standard
Orders (ETSOs) and other regulatory documents.
FAA Federal Aviation Administration –The United States government agency for
aircraft safety and regulation.
FAR Federal Aviation Regulations –The rules and regulations governing the
manufacture, certification, operation, maintenance, repair, and alteration of
aircraft in the United States.
Form 337 FAA Form 337 is required anytime a major repair and/or major alteration is
performed on an aircraft. Refer to FAR, Part 43, Appendix A and the definitions of
Major Repair/Alteration contained in FAR, Part 1 for guidance.
FSDO Flight Standards District Office –FAA district offices responsible for aircraft
certification, operation, maintenance, and modification issues, approvals and
enforcement.

ARTEX PRODUCTS / ACR ELECTRONICS, INC
DESCRIPTION, OPERATION, INSTALLATION AND MAINTENANCE MANUAL
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G-Switch A velocity switch that detects sudden de-acceleration and is used to automatically
activate an ELT. May also be referred to as a “crash sensor”.
LED Light Emitting Diode –Semiconductor device that emits light when current is
passed through it. Usually used as a status or warning indicator.
MIL The three-letter acronym that stands for “Military” and proceeds military
specifications and standards numbers (e.g., MIL-W-xxxx would indicate a wire
specification and MIL-STD-xxxx would indicate a standard).
P/N Part Number –Refers to an ACR Electronics part number, unless otherwise noted.
Part numbers are also indicated with parentheses (e.g., xxx-xxxx)
Plug The term “Plug”, within the context of this document, refers to the male half of an
electrical connector.
Receptacle The term “Receptacle”, within the context of this document, refers to the female
half of an electrical connector.
RF Radio Frequency –The range of electromagnetic radiation that constitutes the
radio spectrum and corresponds to the frequency of alternating current electrical
signals used to produce and detect radio waves.
RTCA Radio Technical Commission for Aeronautics –Organization that makes
recommendations for airworthiness. Refer to http://www.rtca.org/aboutrtca.asp
for more information.
RTV A rubbery silicon-based adhesive typically used to prevent vibration problems and
water intrusion.
SAR Search and Rescue
Screen Room The term “Screen Room”, within the context of this document, refers to a room
designed to suppress RF signals, such that the broadcast of an ELT placed in the
screen room cannot reach the SAR satellite system.
Service Loop A length of wire or cable, at the connection point, of sufficient length to allow a
component to be withdrawn from its mounting position and disconnected from its
associated wiring.
Tether A tether is a cord or similar device that anchors something movable to a stationary
point or anchors two items together, such that they cannot become separated
beyond the length of the tether.
TNC Connector A threaded version of a BNC connector.
TPS Connector A small, rugged, three-pin bayonet locking connector designed for use when
space and weight limitations are of primary concern.
TSO Technical Standard Order –A TSO is a minimum performance standard issued by
the FAA for specified materials, parts, processes, and appliances used on civil
aircraft.
UTC Coordinated Universal Time –A time standard based on International Atomic
Time. UTC is the time system used in aviation and is often associated with
Greenwich Mean Time (GMT) and/or “Zulu” time.
VHF Very High Frequency –The 30 MHz to 300 MHz radio frequency band.
VSWR Voltage Standing Wave Ratio –Electrical signals will “echo” back on a wire if load
impedance is not matched to the impedance of the wire. VSWR is a measurement
of the amount of voltage being “echoed,” compared to the original signal.

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TASK 25-62-03-990-806
6. References
SUBTASK 25-62-03-990-001
A. Regulatory Documents
1) The following regulatory documents are referred to herein. When referring to such documents, it is the
manual user’s responsibility to ensure they are using the latest revision or release of such documents. To
that end, the revision designator of specific document numbers has not been included, with the
exception of the RTCA document listing, which reflects the revision level of the documents at the time
of TSO testing and certification.
2) Except in the case of a printed manual, reference documents available on-line or source locations are
linked to applicable web sites.
3) United States
a) AC 43-9, “Maintenance Records”
b) AC 43-210, “Standardized Procedures for Requesting Field Approval of Data, Major Alterations, and
Repairs”
c) AC 43.9-1, “Instructions for Completion of FAA Form 337”
d) AC 43-13-1, “Acceptable Methods, Techniques, and Practices – Aircraft Inspection and Repair”
e) AC 43.13-2, “Acceptable Methods, Techniques, and Practices - Aircraft Alterations”
f) FAR, Part 43, “Maintenance, Preventive Maintenance, Rebuilding, and Alteration”
g) FAR, Part 91, “General Operating and Flight Rules”
4) Canada
a) CAR, Part V, “Airworthiness”
b) CAR, Part VI, “General Operating and Flight Rules”
5) COSPAS-SARSAT
a) C/S G.005, “Cospas-Sarsat Guidelines on 406 MHz Beacon Coding, Registration and Type Approval”
b) C/S S.007, “Handbook of Beacon Regulations”
6) RTCA –The following documents are available for purchase at RTCA’s web site www.rtca.org, or by
mail:
a) DO-160D, “Environmental Conditions and Test Procedures for Airborne Equipment”
b) DO-178B, “Software Considerations in Airborne Systems and Equipment Certification”
c) DO-182, “Emergency Locator Transmitter (ELT) Equipment Installation and Performance”
d) DO-183, “Minimal Operational Performance Standards for Emergency Locator Transmitters -
Automatic Fixed-ELT (AF), Automatic Portable-ELT (AP), Automatic Deployable-ELT (AD),
Survival-ELT (S) Operating on 121.5 and 243.0 MHz”
e) DO-204, “Minimal Operational Performance Standards for 406 MHz Emergency Locator
Transmitters (ELT)”
SUBTASK 25-62-03-990-002
B. Other Documents
1) The following documents are available on-line at the Artex products web site at www.acrartex.com, or
from ACR Electronics upon request.
a) 570-1000, “ELT Test Set (ETS) Operation Manual”
b) 570-6501, “ELT/NAV Interface -B Description, Operation, Installation and Maintenance Manual”

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DESCRIPTION AND OPERATION
TASK 25-62-03-870-801
1. Description
SUBTASK 25-62-03-870-001
A. Functional Overview
1) The ELT automatically activates during a crash and transmits the standard sweep tone on 121.5 and
243.0 MHz. Approximately every 50 seconds, for up to 520 milliseconds (long message protocol), the
406 MHz transmitter turns on. During that time, an encoded digital message is sent to the
COSPAS-SARSAT Search and Rescue (SAR) satellite system.
2) The information contained in the message includes:
a) Serial number assigned to the ELT by the beacon manufacturer or the national beacon registration
authority, or
b) Aircraft identification or registration number, and
c) Country of registration and country code; plus
d) Position coordinates, when coupled with an ELT/NAV Interface -B (453-6501). Refer to the ELT/NAV
Interface -B Description, Operation, Installation and Maintenance Manual (570-6501) for a detailed
discussion of the interaction between the ELT, ELT/NAV Interface -B, and aircraft navigation
system.
3) The 406 MHz transmitter will operate for 24 hours and then shuts down automatically. The 121.5/243.0
transmitter will continue to operate until the batteries are exhausted, which is at least 50 hours.
4) The 406 MHz transmitter produces a much more accurate position, typically 3 kilometers as compared
with 15 to 20 kilometers for 121.5/243.0 MHz transmitters. When coupled to the aircraft navigation
system via the ELT/NAV Interface -B, the accuracy improves to approximately 100 meters.
5) The ELT transmits a digital message that allows search and rescue authorities to contact the
owner/operator of the aircraft through information contained in a database. Information contained in
the database includes:
a) Type of aircraft and aircraft registration number,
b) Owner address and telephone number, and
c) Alternate emergency contact.
6) After the ELT is activated and the 406 MHz signal is detected by the SAR satellite system and a position
is calculated, the 121.5/243.0 MHz transmissions are used to home in on the crash site.
NOTE: Effective February 1, 2009, COSPAS-SARSAT has terminated satellite processing of distress
signals from 121.5 and 243.0 MHz beacons.
7) Aircraft communications transceivers are not capable of receiving 406 MHz transmissions; therefore, the
only methods of monitoring the ELT are:
a) The cockpit remote switch panel light,
b) The buzzer, or
c) 121.5/243.0 MHz transmissions, which can be monitored using the aircraft communications
transceiver or an AM radio tuned to 121.5 MHz.

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SUBTASK 25-62-03-870-002
B. Components
1) The B406-4 ELT main assembly is housed in a high impact, fire resistant, polycarbonate plastic case,
which is enclosed in a protective mounting frame assembly made of similar material. See Figure 1
B406-4 ELT and Mounting Frame Assembly.
NOTE: The ELT main assembly and its mounting frame assembly are capable of withstanding
extremely harsh environments and have been subjected to the rigorous environmental
testing required by COSPAS-SARSAT for certification.
Figure 1 B406-4 ELT and Mounting Frame Assembly
2) The cockpit-mounted Control Panel G737 (remote switch panel assembly) is a backlit panel comprised of
an ELT status indicator light and a control switch, which allows an operator to manually activate the ELT
for testing and reset (i.e., deactivate) the ELT. See Figure 2 Remote Switch Panel Assembly Front View.
NOTE: The ELT CANNOT be disarmed or disabled from the cockpit. Cockpit operation is limited to
deactivating the ELT (i.e., reset) or manually activating the ELT.
Figure 2 Remote Switch Panel Assembly Front View

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3) The buzzer (i.e., horn) provides an audible alert when the ELT is active. See Figure 3 Buzzer.
Figure 3 Buzzer
4) The battery pack for the B406-4 ELT consists of four “D” size lithium manganese dioxide cells connected
in series. In an effort to increase the safety of the battery pack, a number of features were designed into
the battery pack. To prevent the cells from being charged, diodes are connected across each cell and
fuses are connected to the output. See Figure 4 Battery Pack Assembly.
Figure 4 Battery Pack Assembly

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5) Five dual-input antennas are approved for use with the B406-4 ELT. Selection of the proper antenna is
dependent upon end use, aircraft configuration, speed, and other factors. See Figure 5 Antennas.
Figure 5 Antennas