ENSTROM F-28F Series User manual

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ENSTROM F-28F/280F SERIES MAINTENANCE MANUAL
SUPPLEMENT 1 AVIONIC SYSTEMS
Revision 7, dated Aug 28/17, applies to the Enstrom F-28F/280F Series Maintenance Manual,
Supplement 1 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.
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i through ii i through ii
v through vi* v through vi*
vii through INTRO-2 vii through INTRO-4
7-11 through 7-12 7-11 through 7-12
8-1 through 8-20 8-1 through 8-18
None 10-1 through 10-12
None 11-1 through 11-10
* The existing Record of Revisions page may be retained; Removal/Insertion of this page is
unnecessary.
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Rev. 7
i Aug 28/17
ENSTROM F-28F/280F SERIES MAINTENANCE MANUAL
SUPPLEMENT 1
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.
Copyright 2008-2017 by
The Enstrom Helicopter Corporation
2209 22nd Street
Menominee, Michigan 49858-3515
Telephone: [phone]
Fax: [phone]

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RECORD OF REVISIONS
REV
NO. ISSUE DATE DATE INSERTED BY REV NO. ISSUE DATE DATE INSERTED BY
1 Nov 21/08 Nov 21/08
2 Dec 8/08 Dec 8/08
3 Nov 11/11 Nov 11/11
4 Jan 9/14 Jan 9/14
5 Apr 15/15 Apr 15/15
6 Aug 3/15 Aug 3/15
7 Aug 28/17 Aug 28/17

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ENSTROM F-28F/280F SERIES MAINTENANCE MANUAL SUPPLEMENT 1
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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
Service Document Publications..............................................INTRO-2
Application of Warnings, Cautions, and Notes .......................INTRO-3
Chapter 1 SL30 Nav/Com
System Description ......................................................................... 1-1
Airworthiness Limitations................................................................. 1-2
Servicing.......................................................................................... 1-3
Troubleshooting.......................................................................... 1-3
Periodic Inspections.................................................................... 1-3
System Maintenance....................................................................... 1-4
Electrical Diagram ........................................................................... 1-7
Chapter 2 Sandia SAE5-35 Altitude Data System
System Description ......................................................................... 2-1
Airworthiness Limitations................................................................. 2-2
Servicing.......................................................................................... 2-3
Troubleshooting.......................................................................... 2-3
Periodic Inspections.................................................................... 2-3
System Maintenance....................................................................... 2-4
Electrical Diagram ........................................................................... 2-7
Chapter 3 Garmin GNS 430W/530W GPS/WAAS Navigator
System Description ......................................................................... 3-1
Airworthiness Limitations................................................................. 3-2
Servicing.......................................................................................... 3-3
Cleaning ..................................................................................... 3-3
Troubleshooting.......................................................................... 3-3
Periodic Inspections.................................................................... 3-3
System Maintenance....................................................................... 3-5
Electrical Diagram ........................................................................... 3-7

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TABLE OF CONTENTS
Chapter Description Page
Chapter 4 Garmin GDL 69/69A XM Satellite Weather/Radio
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 Attitude Indicator and Directional Gyro
System Description ......................................................................... 5-1
Airworthiness Limitations................................................................. 5-2
Servicing, Troubleshooting, and Periodic Inspections..................... 5-3
System Maintenance....................................................................... 5-4
Figures and Electrical Diagrams ..................................................... 5-5
Chapter 6 KX 165A COMM/NAV System
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 GTX 330 with ADS-B Out
System Description ......................................................................... 7-1
Airworthiness Limitations................................................................. 7-2
Servicing, Troubleshooting, and Periodic Inspections..................... 7-3
System Maintenance....................................................................... 7-5
Figures and Electrical Diagrams ................................................... 7-11
Chapter 8 GTN 650
System Description ......................................................................... 8-1
Airworthiness Limitations................................................................. 8-2
Servicing, Troubleshooting, and Periodic Inspections..................... 8-3
System Maintenance....................................................................... 8-4
Figures and Electrical Diagrams ..................................................... 8-5
Chapter 9 Dual Start Collective Control Installation
System Description ......................................................................... 9-1
Airworthiness Limitations................................................................. 9-1
Servicing, Troubleshooting, and Periodic Inspections..................... 8-1
System Maintenance....................................................................... 8-2
Figures and Electrical Diagrams ..................................................... 8-2

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TABLE OF CONTENTS
Chapter Description Page
Chapter 10 GNC 255A Nav/Com
System Description .......................................................................10-1
Airworthiness Limitations...............................................................10-2
Servicing, Troubleshooting, and Periodic Inspections...................10-3
System Maintenance.....................................................................10-4
Figures and Electrical Diagrams ...................................................10-5
Chapter 11 MD200 Series CDI
System Description .......................................................................11-1
Airworthiness Limitations...............................................................11-1
Servicing, Troubleshooting, and Periodic Inspections...................11-2
System Maintenance.....................................................................11-3
Figures and Electrical Diagrams ...................................................11-3

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EFFECTIVE PAGE LIST
Page Date Page Date
i Aug 28/17
ii Nov 11/11
iii Jan 9/14
iv Jan 9/14
v Aug 28/17
vi Jan 9/14
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ix Aug 28/17
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xii Aug 28/17
INTRO-1 Aug 28/17
INTRO-2 Aug 28/17
INTRO-3 Aug 28/17
INTRO-4 Aug 28/17
1-1 Jan 9/14
1-2 Nov 11/11
1-3 Jan 9/14
1-4 Nov 18/08
1-5 Nov 18/08
1-6 Nov 18/08
1-7 Nov 18/08
1-8 Nov 18/08
2-1 Nov 21/08
2-2 Nov 11/11
2-3 Nov 21/08
2-4 Nov 21/08
2-5 Nov 21/08
2-6 Nov 21/08
2-7 Nov 21/08
2-8 Nov 21/08
3-1 Dec 8/08
3-2 Nov 11/11
3-3 Dec 8/08
3-4 Dec 8/08
3-5 Dec 8/08
3-6 Dec 8/08
3-7 Dec 8/08
3-8 Dec 8/08
4-1 Dec 8/08
4-2 Nov 11/11
4-3 Dec 8/08
4-4 Dec 8/08
4-5 Dec 8/08
4-6 Dec 8/08
4-7 Dec 8/08
4-8 Dec 8/08
5-1 Nov 11/11
5-2 Nov 11/11
5-3 Nov 11/11
5-4 Nov 11/11
5-5 Nov 11/11
5-6 Nov 11/11
5-7 Nov 11/11
5-8 Nov 11/11
6-1 Jan 9/14
6-2 Jan 9/14
6-3 Jan 9/14
6-4 Jan 9/14
6-5 Jan 9/14
6-6 Jan 9/14
6-7 Jan 9/14
6-8 Jan 9/14
6-9 Jan 9/14
6-10 Jan 9/14
7-1 Apr 15/15
7-2 Apr 15/15
7-3 Apr 15/15
7-4 Apr 15/15
7-5 Apr 15/15
7-6 Apr 15/15
7-7 Apr 15/15
7-8 Apr 15/15
7-9 Apr 15/15
7-10 Apr 15/15
7-11 Apr 15/15
7-12 Aug 28/17
7-13 Apr 15/15
7-14 Apr 15/15
7-15 Apr 15/15
7-16 Apr 15/15
7-17 Apr 15/15
7-18 Apr 15/15
8-1 Aug 28/17
8-2 Apr 15/15
8-3 Aug 28/17
8-4 Aug 28/17
8-5 Aug 28/17
8-6 Aug 28/17

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8-12 Aug 28/17
8-13 Aug 28/17
8-14 Aug 28/17
8-15 Aug 28/17
8-16 Aug 28/17
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9-1 Apr 15/15
9-2 Apr 15/15
9-3 Apr 15/15
9-4 Apr 15/15
10-1 Aug 28/17
10-2 Aug 28/17
10-3 Aug 28/17
10-4 Aug 28/17
10-5 Aug 28/17
10-6 Aug 28/17
10-7 Aug 28/17
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10-10 Aug 28/17
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11-1 Aug 28/17
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ENSTROM F-28F/280F SERIES MAINTENANCE MANUAL SUPPLEMENT 1
Rev. 7
INTRO-1 Aug 28/17
INTRODUCTION
Avionic System(s) Effectivity
A. The data presented in this supplement is applicable to the optional avionic systems
listed in the following table:
Avionic System(s)
Avionic System Enstrom Part Number
Attitude Indicator 28-22062-( )
Collective Control Installation (Dual Start) 28-16080-101
Directional Gyro 28-22062-( )
GDL 69/69A 28-22082-( )
GNC 255A 28-22063-5
GNS 430W 28-22037-( )
GNS 530W 28-22050-( )
GTN 650 28-22112-3
GTX 330 28-22028-1
KX 165A COMM/NAV 28-22063-( )
MD200-306 VOR/LOC/GS Indicator 28-22095-1
MD200-706 VOR/LOC/GS Indicator 28-22095-3
SAE5-35 Altitude Data System 28-22090-( )
SL30 28-22069-1
Aircraft Effectivity
A. The data presented in this F-28F/280F Series Maintenance Manual Supplement is
applicable to all Enstrom F-28F and 280F series 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 F-28F/280F SERIES MAINTENANCE MANUAL SUPPLEMENT 1
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INTRO-2 Aug 28/17
Service Document Publications
(1) 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.
(2) 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.
(3) 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.
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 Tech 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 Tech Publications section of the website.
Enstrom distributes maintenance manual reissues and revisions in hardcopy form via mail
to owners and operators who are registered with Enstrom. Notice of recently released
Service Information Letters and Service Directive Bulletins is provided via a postcard
mailing. Registration to receive publication mailings can be coordinated through Enstrom
Product Support.

ENSTROM F-28F/280F SERIES MAINTENANCE MANUAL SUPPLEMENT 1
Rev. 7
INTRO-3 Aug 28/17
Application of Warnings, Cautions, and Notes
A. Throughout this supplement, it is necessary to highlight or emphasize important
points to avoid injury to personnel, damage to equipment, or unnecessary confusion while
performing maintenance procedures. The terms “WARNING,” “CAUTION,” and “NOTE” are
used to draw attention to instructions or information deserving special consideration.
B.
WARNING
Calls attention to use of materials, processes, methods,
procedures, or limits that must be followed to avoid injury to
personnel.
C.
CAUTION
Calls attention to methods and procedures that must be
followed to avoid damage to equipment.
D.
NOTE
Calls attention to information essential to highlight for
clarification of procedures or to make a task easier.

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1) NACv ≥1
2) SDA ≥2
3) SIL ≥3
4) NACq ≥8
5) NIC ≥7
H. Change the GTX squat switch configuration back to previous as follows:
1) Place the collective fully down.
2) If the GTX squat switch configuration settings were changed in step D, change the
GTX settings back to previous as defined in Section 4-1-5.
I. Test is complete; select STBY mode on the GTX.
4-1-8. Software Update
A. Verify the software version number matches the approved software version listed in
Enstrom Rotorcraft Flight Manual Supplement 28-AC-070. The software version will
appear on the start up screen after power up. If the replaced unit does not have the
approved version of software installed, software can be downloaded from the Garmin
Dealer Resource Center at www.flyGarmin.com.
4-2. Figures and Diagrams
A. The GTX 330 installation is shown in Figure 7-1.
B. The GTX 330 wiring interfaces are shown in Diagram 7-1 through Diagram 7-3.

ENSTROM F-28F/280F SERIES MAINTENANCE MANUAL SUPPLEMENT 1
Rev. 7
7-12 Aug 28/17
VIEW A
Item Part Number Component Quantity
- 28-22028-1 GTX 330 ES Mode S Installation REF
1 010-00230-61 . GTX 330 ES Mode S Transponder 1
2 MS26574-5 . Circuit Breaker 1
3 28-19064-1 . Placard 1
- 28-22183-127 Antenna Installation REF
4 AV-22 . Antenna 1
5 C307PS Temperature Probe 1
Figure 7-1. GTX 330 Installation

ENSTROM F-28F/280F SERIES MAINTENANCE MANUAL SUPPLEMENT 1
Rev. 7
8-1 Aug 28/17
CHAPTER 8
GTN 650 GPS/NAV/COM
SECTION 1
SYSTEM DESCRIPTION
1-1. System Description
A. The GTN 650 installation part number is 28-22112-3. The components of the GTN 650
installation include the GTN 650 unit installed in the lower console and Nav, Com, and
GPS antennas. An optional remote NAV AUDIO switch is included depending on the
audio panel system installed.
B. The GTN 650 is interfaced with an audio panel or VOX ICS audio system. The GTN 650
may also be interfaced with any of the following equipment options: a GNC 255A to
provide GPS position information for the GNC 255A; a GTX 330ES for remote operation
and as a ADS-B Out position source; a CDI, slaved compass system, EHSI, or an EFIS
system to provide a visual presentation of VOR, GPS, LOC and GS information; and a
fuel management system.
C. The GTN 650 utilizes Navigation, Basemap, SafeTaxi, Terrain and Obstacle databases
for the map display. A Secure Digital (SD) card is used to load and store various types of
data. For basic flight operations, the SD card is required for Terrain, Obstacle, and
SafeTaxi database storage as well as Jeppesen aviation database updates.
D. Power to the GTN 650 is provided via the COM circuit breaker (CB44) (5 Amp) and the
NAV/GPS circuit breaker circuit breaker (CB43) (5 Amp) located on the left side of the
lower console. The NAV/GPS circuit breaker also provides power to the CDI.
E. Refer to F-28F/280FX Rotorcraft Flight Manual Supplement 28-AC-069 for GTN 650
limitations and basic operation instructions.
1-2. Vendor Manuals
A. The following components listed in Table 8-1 are to be operated and maintained I/A/W
the current vendor’s instructions to ensure the continued airworthiness of the aircraft.
Table 8-1. Vendor Manuals
Component Publication Vendor
GTN 650 GTN 625/635/650 Installation Manual,
Document No 190-01004-02, latest revision
Garmin International, Inc.
1200 East 151st Street
Olathe, KS 66062
Tele: [phone]
Fax: [phone]
www.garmin.com
GTN 625/635/650 Pilot’s Guide, Document No.
190-01004-03, latest revision
GTN 625/635/650 Cockpit Reference Guide,
Document No. 190-01004-04, latest revision

ENSTROM F-28F/280F SERIES MAINTENANCE MANUAL SUPPLEMENT 1
Rev. 5
8-2 Apr 15/15
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. All components of the GTN 650 installation are “on condition.”