ENSTROM TH-28/480 Series User manual

Page 1 of 2
ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL
SUPPLEMENT 5 AVIONIC SYSTEMS
Revision 18 Changed Pages
May 26, 2020
Revision 18, dated Apr 30/2020, applies to the Enstrom TH-28/480 Series Maintenance Manual,
Supplement 5 Avionics Systems.
Remove and insert the pages listed below. Avoid unintentional removal of pages by following this
list carefully. Special instructions are denoted with asterisks where applicable.
Remove Pages Insert Pages
i through ii i through ii
v through viii * v through viii
xi through INTRO-2 xi through INTRO-2
1-1 through 1-2 1-1 through 1-2
2-1 through 2-2 2-1 through 2-2
3-1 through 3-2 3-1 through 3-2
5-1 through 5-2 5-1 through 5-2
6-1 through 6-2 6-1 through 6-2
6-5 through 6-8 6-5 through 6-8
None 6-13 through 6-16
7-1 through 7-2 7-1 through 7-2
8-1 through 8-2 8-1 through 8-2
9-13 through 9-14 9-13 through 9-14
11-1 through 11-8 11-1 through 11-8
11-15 through 11-26 11-15 through 11-26
* Removal/Insertion of the Record of Revision page (page v) is unnecessary if Revision 18 date and
issue information is recorded.
.....................................................Continued on the Next Page.....................................................

Page 2 of 2
...................................................Continued from Previous Page...................................................
Remove Pages Insert Pages
11-33 through 12-2 11-33 through 12-2
13-1 through 13-2 13-1 through 13-2
14-1 through 14-2 14-1 through 14-2
15-1 through 15-2 15-1 through 15-2
16-7 through 16-10 16-7 through 16-10
17-5 through 17-6 17-5 through 17-6
17-11 through 17-12 17-11 through 17-12
...................................................................End of List...................................................................

Rev. 18
i Apr 30/2020
ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL
SUPPLEMENT 5
AVIONIC SYSTEMS
The Airworthiness Limitations Section is FAA approved and specifies inspections and
other maintenance required under 14 CFR §§ 43.16 and 91.403 of the Federal Aviation
Regulations unless an alternative program has been FAA approved.
For EASA approval, the Airworthiness Limitations Section is approved and variations
must also be approved.
Copyright 2008-2020 by
The Enstrom Helicopter Corporation
2209 22
nd
Street
Menominee, Michigan 49858
Telephone: [phone]
Fax: [phone]

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 8
ii Apr 27/12
INTENTIONALLY LEFT BLANK

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 18
v Apr 30/2020
RECORD OF REVISIONS
REV
NO.
ISSUE
DATE
DATE
INSERTED
BY REV NO. ISSUE
DATE
DATE
INSERTED
BY
1 Nov 21/08 Nov 21/08 JW
2 Mar 9/09 Mar 9/09 JW
3 Jul 14/10 Jul 14/10 JW
4 Nov 9/10 Nov 9/10 JW
5 Jan 14/11 Jan 14/11 JW
6 Feb 24/11 Feb 24/11 JW
7 Nov 11/11 Nov 11/11 JW
8 Apr 27/12 Apr 27/12 JW
9 May 1/13 May 1/13 JW
10 Jun 5/14 Jun 5/14 JW
11 Nov 12/14 Nov 12/14 JW
12 Feb 18/15 Feb 18/15 JW
13 Oct 20/15 Oct 20/15 JW
14 Dec 20/17 Dec 20/17 JW
15 Aug 15/18 Aug 15/18 JW
16 May 7/19 May 7/19 JW
17 May 23/19 May 23/19 JW
18 Apr 30/20 May 26/20 JW

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 10
vi Jun 5/14
INTENTIONALLY LEFT BLANK

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 18
vii Apr 30/2020
TABLE OF CONTENTS
Chapter Description Page
Cover Page ......................................................................................... i
Recommended Change Report..........................................................iii
Record of Revisions ........................................................................... v
Table of Contents ..............................................................................vii
Effective Page List..............................................................................ix
Introduction
Avionic System(s) Effectivity ..................................................INTRO-1
Aircraft Effectivity....................................................................INTRO-1
Supplemental Changes and Revisions ..................................INTRO-1
Application of Warnings, Cautions, and Notes .......................INTRO-3
Chapter 1 TAS600 Traffic Advisory System
System Description ......................................................................... 1-1
Airworthiness Limitations................................................................. 1-2
Servicing.......................................................................................... 1-3
Troubleshooting.......................................................................... 1-3
Periodic Inspections.................................................................... 1-3
System Maintenance....................................................................... 1-4
TAS600 Processor...................................................................... 1-4
TAS600 Transponder/Coupler.................................................... 1-5
TAS600 Antennas....................................................................... 1-5
TAS600 Wiring Harnesses/Connectors ...................................... 1-6
Figures and Electrical Diagrams ..................................................... 1-7
Chapter 2 SL30 NAV COM Transceiver
System Description ......................................................................... 2-1
Airworthiness Limitations................................................................. 2-2
Servicing.......................................................................................... 2-3
Troubleshooting.......................................................................... 2-3
Periodic Inspections.................................................................... 2-3
System Maintenance....................................................................... 2-4
Figures and Electrical Diagrams ..................................................... 2-5
Chapter 3 Sandia SAE5-35 Altitude Data System
System Description ......................................................................... 3-1
Airworthiness Limitations................................................................. 3-2
Servicing.......................................................................................... 3-3
Troubleshooting.......................................................................... 3-3
Periodic Inspections.................................................................... 3-3
System Maintenance....................................................................... 3-4
Electrical Diagram ........................................................................... 3-7

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 15
viii Aug 15/18
TABLE OF CONTENTS
Chapter Description Page
Chapter 4 Mid-Continent Instruments MD200 Series CDI
System Description ......................................................................... 4-1
Airworthiness Limitations................................................................. 4-2
Servicing.......................................................................................... 4-3
Troubleshooting.......................................................................... 4-3
Periodic Inspections.................................................................... 4-3
System Maintenance....................................................................... 4-4
Electrical Diagram ........................................................................... 4-7
Chapter 5 Safe Flight Powerline Detection System
System Description ......................................................................... 5-1
Airworthiness Limitations................................................................. 5-2
Servicing.......................................................................................... 5-3
Troubleshooting.......................................................................... 5-3
Periodic Inspections.................................................................... 5-3
Special Instructions..................................................................... 5-3
System Maintenance....................................................................... 5-5
Functional Test ........................................................................... 5-9
Figures and Electrical Diagram ..................................................... 5-10
Chapter 6 NAT Dual Channel Audio Controller / NAT Audio Mixing Amplifier
System Description ......................................................................... 6-1
Airworthiness Limitations................................................................. 6-2
Servicing, Troubleshooting, and Periodic Inspections..................... 6-3
System Maintenance....................................................................... 6-4
Figures and Electrical Diagrams ..................................................... 6-5
Chapter 7 Attitude Indicator and Directional Gyro
System Description ......................................................................... 7-1
Airworthiness Limitations................................................................. 7-2
Servicing, Troubleshooting, and Periodic Inspections..................... 7-3
System Maintenance....................................................................... 7-4
Figures and Electrical Diagrams ..................................................... 7-5
Chapter 8 Garmin GNS 430W/530W GPS/WAAS Navigator
System Description ......................................................................... 8-1
Airworthiness Limitations................................................................. 8-2
Servicing, Troubleshooting, and Periodic Inspections..................... 8-3
System Maintenance....................................................................... 8-4
Figures and Electrical Diagrams ..................................................... 8-6

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 18
xi Apr 30/2020
EFFECTIVE PAGE LIST
Page Date Page Date
i Apr 30/2020
ii Apr 27/12
iii Aug 15/18
iv Jun 5/14
v Apr 30/2020
vi Jun 5/14
vii Apr 30/2020
viii Aug 15/18
ix May 7/19
x Aug 15/18
xi Apr 30/2020
xii Apr 30/2020
xiii Apr 30/2020
xiv Dec 20/17
INTRO-1 May 7/19
INTRO-2 Apr 30/2020
INTRO-3 Dec 20/17
INTRO-4 Dec 20/17
1-1 Nov 5/08
1-2 Apr 30/2020
1-3 Nov 5/08
1-4 Nov 5/08
1-5 Nov 5/08
1-6 Nov 5/08
1-7 Nov 5/08
1-8 Nov 5/08
1-9 Nov 5/08
1-10 Nov 5/08
1-11 Nov 5/08
1-12 Nov 5/08
1-13 Nov 5/08
1-14 Nov 5/08
2-1 Apr 27/12
2-2 Apr 30/2020
2-3 Nov 9/10
2-4 Nov 9/10
2-5 Apr 27/12
2-6 Apr 27/12
3-1 Mar 9/09
3-2 Apr 30/2020
3-3 Mar 9/09
3-4 Mar 9/09
3-5 Mar 9/09
3-6 Mar 9/09
3-7 Mar 9/09
3-8 Mar 9/09
4-1 May 7/19
4-2 Aug 15/18
4-3 Aug 15/18
4-4 Aug 15/18
4-5 Aug 15/18
4-6 Aug 15/18
4-7 Aug 15/18
4-8 Aug 15/18
4-9 May 7/19
4-10 Aug 15/18
5-1 Feb 24/11
5-2 Apr 30/2020
5-3 Feb 24/11
5-4 Feb 24/11
5-5 Feb 24/11
5-6 Feb 24/11
5-7 Feb 24/11
5-8 Feb 24/11
5-9 Feb 24/11
5-10 Feb 24/11
5-11 Feb 24/11
5-12 Feb 24/11
6-1 Jan 14/11
6-2 Apr 30/2020
6-3 Jan 14/11
6-4 Jan 14/11
6-5 Apr 30/2020
6-6 Jan 14/11
6-7 Apr 30/2020
6-8 Jan 14/11
6-9 Jun 5/14
6-10 Jun 5/14
6-11 Nov 12/14
6-12 Nov 12/14
6-13 Apr 30/2020
6-14 Apr 30/2020
6-15 Apr 30/2020
6-16 Apr 30/2020
7-1 Nov 11/11
7-2 Apr 30/2020
7-3 Nov 11/11
7-4 Nov 11/11
7-5 Nov 11/11
7-6 Nov 11/11
7-7 Nov 11/11
7-8 Nov 11/11
8-1 May 1/13
8-2 Apr 30/2020
8-3 May 1/13
8-4 May 1/13
8-5 May 1/13
8-6 May 1/13

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 18
xii Apr 30/2020
EFFECTIVE PAGE LIST
Page Date Page Date
8-7 May 1/13
8-8 May 1/13
8-9 May 1/13
8-10 May 1/13
8-11 May 1/13
8-12 May 1/13
8-13 May 1/13
8-14 May 1/13
9-1 Aug 15/18
9-2 Aug 15/18
9-3 Nov 12/14
9-4 Dec 20/17
9-5 Aug 15/18
9-6 Aug 15/18
9-7 Aug 15/18
9-8 Aug 15/18
9-9 Aug 15/18
9-10 Aug 15/18
9-11 Dec 20/17
9-12 Dec 20/17
9-13 Apr 30/2020
9-14 Apr 30/2020
10-1 Aug 15/18
10-2 Aug 15/18
10-3 Oct 20/15
10-4 Nov 12/14
10-5 May 7/19
10-6 May 7/19
10-7 May 7/19
10-8 May 7/19
10-9 May 7/19
10-10 May 7/19
10-11 May 7/19
10-12 May 7/19
11-1 Apr 30/2020
11-2 May 7/19
11-3 May 7/19
11-4 Apr 30/2020
11-5 Apr 30/2020
11-6 Apr 30/2020
11-7 Apr 30/2020
11-8 Apr 30/2020
11-9 Aug 15/18
11-10 Aug 15/18
11-11 Aug 15/18
11-12 Aug 15/18
11-13 Dec 20/17
11-14 Dec 20/17
11-15 Apr 30/2020
11-16 Apr 30/2020
11-17 Apr 30/2020
11-18 Apr 30/2020
11-19 Apr 30/2020
11-20 Apr 30/2020
11-21 Apr 30/2020
11-22 Apr 30/2020
11-23 Apr 30/2020
11-24 Apr 30/2020
11-25 Apr 30/2020
11-26 Apr 30/2020
11-27 Aug 15/18
11-28 Aug 15/18
11-29 May 7/19
11-30 May 7/19
11-31 Aug 15/18
11-32 Aug 15/18
11-33 Apr 30/2020
11-34 Apr 30/2020
12-1 Nov 12/14
12-2 Apr 30/2020
12-3 Nov 12/14
12-4 Nov 12/14
12-5 Nov 12/14
12-6 Nov 12/14
12-7 Nov 12/14
12-8 Nov 12/14
12-9 May 7/19
12-10 May 7/19
13-1 Nov 12/14
13-2 Apr 30/2020
13-3 Nov 12/14
13-4 Nov 12/14
13-5 Nov 12/14
13-6 May 7/19
13-7 Nov 12/14
13-8 Nov 12/14
13-9 Nov 12/14
13-10 Nov 12/14
13-11 Nov 12/14
13-12 Nov 12/14
13-13 Nov 12/14
13-14 Nov 12/14
13-15 Nov 12/14
13-16 Nov 12/14
13-17 May 7/19
13-18 May 7/19

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 18
xiii Apr 30/2020
EFFECTIVE PAGE LIST
Page Date Page Date
14-1 Dec 20/17
14-2 Apr 30/2020
14-3 Dec 20/17
14-4 Oct 20/15
14-5 Dec 20/17
14-6 Dec 20/17
14-7 Dec 20/17
14-8 Dec 20/17
14-9 Dec 20/17
14-10 Dec 20/17
14-11 Dec 20/17
14-12 Dec 20/17
14-13 Dec 20/17
14-14 Dec 20/17
15-1 Dec 20/17
15-2 Apr 30/2020
15-3 Dec 20/17
15-4 Dec 20/17
15-5 Dec 20/17
15-6 Dec 20/17
15-7 Dec 20/17
15-8 Dec 20/17
15-9 Dec 20/17
15-10 Dec 20/17
16-1 May 7/19
16-2 May 7/19
16-3 May 7/19
16-4 May 7/19
16-5 May 7/19
16-6 May 7/19
16-7 Apr 30/2020
16-8 May 7/19
16-9 Apr 30/2020
16-10 May 7/19
16-11 May 7/19
16-12 May 7/19
17-1 Aug 15/18
17-2 Aug 15/18
17-3 Aug 15/18
17-4 Aug 15/18
17-5 Aug 15/18
17-6 Apr 30/2020
17-7 May 23/19
17-8 May 23/19
17-9 May 23/19
17-10 May 23/19
17-11 Apr 30/2020
17-12 Apr 30/2020

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 14
xiv Dec 20/17
INTENTIONALLY LEFT BLANK

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 16
INTRO-1 May 7/19
INTRODUCTION
Avionic System(s) Effectivity
A. The data is presented in this supplement is applicable to the optional avionic system(s)
listed in the following table.
Avionic System(s)
Avionic System Enstrom Part Number
Appareo Systems Vision 1000 4220641-( )
Attitude Indicator 4220542-( )
TAS600 4220569-1
Directional Gyro 4220542-( )
RA-4500 Radar Altimeter 4220517-( )
GMA 350H Audio Panel 4220672-3, -5, -7, -9
GMA 350Hc Audio Panel 4220672-109, -111
GNC 255A Nav/Comm 4220638-1
GNS 430W GPS/Nav/Comm 4220535-( )
GNS 530W GPS/Nav/Comm 4220534-( )
GTN 650 GPS/Nav/Comm 4220639-( )
GTN 750 GPS/Nav/Comm 4220644-( )
GTX 327 Transponder 4220512-1, -5
GTX 345 Transponder 4220645-5
SL30 Nav/Comm 4220558-( )
MD200 Series CDI 4220574-( )
NAT 247 Audio Mixing Amplifier 4220529-5
NAT AMS44 Dual Channel Audio Controller 4220529-1, -3 (NVIS)
Safe Flight Powerline Detection System 4220576-( )
SN3500 EHSI 4220609-5, -7
SAE5-35 Altitude Data System 4220561-( )
Aircraft Effectivity
A. The data presented in this TH-28/480 Series Maintenance Manual Supplement is
applicable to all Enstrom 480 and 480B model helicopters.
Supplemental Changes and Revisions
A. Subsequent to the publication of the initial issue of this supplement, changes in the
avionics equipment, support concepts and procedures, as well as information developed by
experience may affect the contents of this supplement. To ensure that coverage in the
supplement continues to reflect such changes, revised information is released by one of the
following methods:
1. Revision - A revision alters portions of the manual by replacement, addition, and/or
removal of pages.
2. Reissue - A reissue of this supplement will occur when the amount of changes
warrants complete reissue.

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 18
INTRO-2 Apr 30/2020
3. Service Directive Bulletins – Used to direct the owner/operator and/or maintenance
personnel to make mandatory changes, improvements, or inspections to the aircraft
applicable to the entire fleet or a segment of the fleet that are typically
safety/airworthiness related. The information provided in the Service Directive
Bulletins will be incorporated in the maintenance manual as needed at a later date. At
the time of incorporation, the Service Directive Bulletin is superseded by the
maintenance manual, and accomplishment or sign-off of the Service Directive Bulletin
in the maintenance records book is no longer required. A detailed entry should be
made in the maintenance records to indicate that the Service Directive Bulletin is
superseded by the maintenance manual.
4. Service Information Letters – Used to transmit information, recommendations, and
general service instructions to the aircraft owner/operator and/or maintenance
personnel applicable to the entire fleet or a segment of the fleet. The information
provided in the Service Information Letters will be incorporated into the maintenance
manual as needed at a later date.
5. Service Instructions – Used to provide the owner/operator and/or maintenance
personnel with information that is applicable to specific aircraft and does not meet the
criteria of a Service Information Letter or Service Directive Bulletin. Service
Instructions will not be distributed to the entire fleet.
Enstrom distributes maintenance manual supplement revisions and reissues in electronic
form via the Enstrom Helicopter website: www.enstromhelicopter.com (follow the applicable
link under the Technical Publications section of the Technical Support page). Revision
update notices are sent via email to owners and operators who are registered with Enstrom.
Registration to receive publication mailing notifications can be coordinated through the
Enstrom Technical Publications Administrator. A complete manual hardcopy may be
ordered through Enstrom Customer Service.
Service Information Letters and Service Directive Bulletins incorporated into the
maintenance manual are logged in the Service Information Letter Index or the Service
Directive Bulletin Index (as appropriate) located on the Enstrom Helicopter website:
www.enstromhelicopter.com (follow the applicable link under the Technical Publications
section of the Technical Support page). Each index numerically lists all Service Information
Letters and Service Directive Bulletins, respectively, and identifies those which have been
incorporated into the maintenance manual. All Service Information Letters and Service
Directive Bulletins are also located under the Technical Publications section of the website.
Notice of recently released Service Information Letters and Service Directive Bulletins is
provided via email notification. Registration to receive publication mailing notifications can
be coordinated through the Enstrom Technical Publications Administrator.

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
1-1 Nov 5/08
CHAPTER 1
TAS600 TRAFFIC ADVISORY SYSTEM
SECTION 1
SYSTEM DESCRIPTION
1-1. System Description
A. The Avidyne Traffic Advisory System (TAS) is an Airborne Surveillance Radar system.
The TAS600 uses transponder replies to compute bearing, relative altitude, and range from
nearby Mode C- or Mode S-equipped aircraft. Non-Mode C aircraft provide range and bearing
information only. The TAS600 Series System does not detect aircraft without operating
transponders.
B. Traffic information from the Avidyne TAS600 is displayed on the Chelton EFIS, the
Garmin GMX200, or the Garmin GNS430W/530W systems. If the TAS is interfaced with the
Chelton EFIS, audible traffic advisories and annunciator light output are provided by the EFIS
MFD. If the TAS is interfaced with Garmin systems, audible traffic advisories are provided by the
TAS system and the annunciator light output is produced by the Garmin system.
C. Components of the TAS600 installation include the TAS600 processor, a
transponder/coupler, and two antennas.
D. Power to the TAS600 is provided via the TAS circuit breaker (CB118) (3 Amp) located
on the left side of the center pedestal and an ON/OFF power switch (SW82) located on the lower
right side of the center pedestal.
E. Refer to the appropriate 480 or 480B Rotorcraft Flight Manual Supplement and the
current vendor operating manuals/instructions for operation of the TAS600 system.
1-2. Vendor Publications
A. The following components listed in Table 1-1 are to be operated and maintained I/A/W
the current vendor’s instructions to ensure the continued airworthiness of the aircraft:
Table 1-1. Vendor Manuals
Component Publication Vendor
TAS600 Pilot’s Handbook,
Part Number 32-2352,
Revision 6, or subsequent
Avidyne Corporation
55 Old Bedford Rd.
Lincoln, MA 01773

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 18
1-2 Apr 30/2020
SECTION 2
AIRWORTHINESS LIMITATIONS
2-1. Airworthiness Limitations
A. The Airworthiness Limitations Section is FAA approved and specifies inspections and
other maintenance required under 14 CFR §§ 43.16 and 91.403 of the Federal Aviation
Regulations unless an alternative program has been FAA approved.
B. For EASA approval, the Airworthiness Limitations Section is approved and variations
must also be approved.
C. All components of the TAS600 system are “on condition”.

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 8
2-1 Apr 27/12
CHAPTER 2
SL30 NAV COM
SECTION 1
SYSTEM DESCRIPTION
1-1. System Description
A. The Garmin SL30 NAV/COM unit is a VHF Navigation/Communications Transceiver
utilizing high performance Digital Signal Processing (DSP) filtering. It includes a 760-channel VHF
Com transceiver and a 200-channel VOR/LOC/GS navigation receiver.
B. Functions and features of the SL30 include automatic decoding of the Morse code
station identifier for VOR/LOC, memory storage for most-used frequency, built-in course deviation
indicator, standby Com and Nav frequency monitoring, Nav receiving for both VOR and LOC
navigation signals, and built in Glideslope receiver.
C. The components of the SL30 system include the panel mounted SL30 unit and nav
and com antennas. If equipped, a dual SL30 installation contains two Garmin SL30 NAV/COM
units that share one nav antenna and include two separate, independent com antennas. The
SL30(s) provide output to a VOR/LOC/GS indicator and to either a VOX ICS or an audio panel.
D. The part number 4220558-( ) SL30 may be configured with a diode or an LED-based
back course annunciator, each of which may be installed on the upper instrument panel.
E. Power to the SL30 unit is provided via the COM circuit breaker (CB61) (5 Amp) and
the NAV circuit breaker (CB63) (2 Amp) located on the left side of the center pedestal. If equipped,
power to the second SL30 unit is provided via the COM2 circuit breaker (also designated CB61)
(5 Amp) and NAV2 circuit breaker (also designated CB63) (2 Amp) located on the left side of the
center pedestal.
F. Refer to the 480B Rotorcraft Flight Manual Supplement and the current vendor
operating manuals/instructions for operation of the SL30 system.
1-2. Vendor Publications
A. The SL30 is to be operated and maintained I/A/W the current vendor’s instructions to
ensure the continued airworthiness of the aircraft. The applicable vendor manuals are listed in
Table 2-1.
Table 2-1. Vendor Manuals
Component Publication Vendor
SL30 SL30 Nav Com Pilot’s Guide Garmin International
1200 E. 151st Street
Olathe, KS 66062

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 18
2-2 Apr 30/2020
SECTION 2
AIRWORTHINESS LIMITATIONS
2-1. Airworthiness Limitations
A. The Airworthiness Limitations Section is FAA approved and specifies inspections and
other maintenance required under 14 CFR §§ 43.16 and 91.403 of the Federal Aviation
Regulations unless an alternative program has been FAA approved.
B. For EASA approval, the Airworthiness Limitations Section is approved and variations
must also be approved.
C. All components of the SL30 system are “on condition”.

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 2
3-1 Mar 9/09
CHAPTER 3
SANDIA SAE5-35 ALTITUDE DATA SYSTEM
SECTION 1
SYSTEM DESCRIPTION
1-1. System Description
A. The Sandia SAE5-35 is a solid state altitude data system (blind encoder) that converts
pressure altitude into a digital output. The data output is referenced to 29.92 in Hg (1013 Millibars).
B. The Sandia SAE5-35 outputs altitude data via Gillham Grey Code or two independent
RS232 digital outputs to Mode C transponders. The transponders utilized include the Bendix/King
KT73, KT76A, and KT76C; and the Garmin GTX327 and GTX330.
C. Two configurations of the Sandia SAE5-35 system are available. They are part
numbers 4220561-1 and 4220561-3. P/N 4220561-1 is the standard system installation and P/N
28-4220561-3 is the standard system with the “Altitude In-Flight Monitoring” function.
D. Power to the Sandia SAE5-35 encoder is provided via the ENCDR circuit breaker
(CB39) (2 Amp) located on the lower left side of the center pedestal.
E. Refer to the 480B Rotorcraft Flight Manual Supplement and the current vendor
operating manuals/instructions for operation of the Sandia SAE5-35 altitude data system.
1-2. Vendor Publications
A. The Sandia SAE5-35 is to be operated and maintained I/A/W the current vendor’s
instructions to ensure the continued airworthiness of the aircraft. The applicable vendor manuals
are listed in Table 3-1.
Table 3-1. Vendor Manuals
Component Publication Vendor
Sandia SAE5-35 1. SAE5-35 Pilot’s Guide,
Document 305221
2. SAE5-35 Altitude Data
System Installation Manual,
Document 305186
Sandia Aerospace, Inc.
3700 Osuna Rd. NE, Suite 171
Albuquerque, NM 87109

ENSTROM TH-28/480 SERIES MAINTENANCE MANUAL SUPPLEMENT 5
Rev. 18
3-2 Apr 30/2020
SECTION 2
AIRWORTHINESS LIMITATIONS
2-1. Airworthiness Limitations
A. The Airworthiness Limitations Section is FAA approved and specifies inspections and
other maintenance required under 14 CFR §§ 43.16 and 91.403 of the Federal Aviation
Regulations unless an alternative program has been FAA approved.
B. For EASA approval, the Airworthiness Limitations Section is approved and variations
must also be approved.
C. All components of the Sandia SAE5-35 system are “on condition”.