Dynon Avionics Cessna 172 F-S Instruction Manual

SkyView HDX System
Autopilot Servo Installation &
Maintenance Manual
Contains Instructions for Continued Airworthiness
Cessna Models 172 F-S
103526-000
Revision D
6/23/2020
Copyright © 2019 by Dynon Avionics, Inc.
Dynon Avionics grants third parties' permission to print this document

Contact Information
Dynon Avionics, Inc.
19825 141st Place NE
Woodinville, WA 98072
Phone: [phone]
Business Operations: 8:00 AM–5:00 PM (Pacific Time) Monday–Friday
Technical Support Operations: 7:00 AM–4:00 PM (Pacific Time) Monday–Friday
Email Sales: [email protected]
Email Support: [email protected]
Fax: [phone]
Web: www.dynoncertified.com
Copyright
©2019 Dynon Avionics, Inc. All rights reserved. No part of this manual may be reproduced, copied, transmitted, disseminated or stored in any
storage medium, for any purpose without the express written permission of Dynon Avionics. Dynon Avionics hereby grants permission to
download a single copy of this manual and of any revision to this manual onto a hard drive or other electronic storage medium to be viewed for
personal use, provided that such electronic or printed copy of this manual or revision must contain the complete text of this copyright notice and
provided further that any unauthorized commercial distribution of this manual or any revision hereto is strictly prohibited.
Information in this document is subject to change without notice. Dynon Avionics reserves the right to change or improve its products and to
make changes in the content without obligation to notify any person or organization of such changes. Visit the Dynon Avionics website
(www.dynonavionics.com) for current updates and supplemental information concerning the use and operation of this and other Dynon Avionics
products.

SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
Page | i
Revision History
REV
DATE
APPROVED
DESCRIPTION OF CHANGE
A
8/31/2018
ECO 312857
Initial Release
B
2/15/2019
ECO 317851
Improved organization and illustrations
C
10/25/2019
ECO 337637
•Re-titled doc to include Maintenance.
•Applied new document template, including adding new
Section 1: Introduction, to clarify use of document. This
content is boilerplate. All subsequent sections renumbered
•Removed part numbers of non-purchasable parts.
•Updated cable clamp material type (polyethylene for
aluminum) in Section 2: Materials.
•Updated illustrations in Section 7: Figures for better
readability/usability.
•Updated format and language of Mounting Bracketry
Installation sections for clarity and readability/usability.
•Updated format and language of Electrical Installation
section for better readability/usability.
D
6/23/20
CO 349445
Revision update due to online version of document having
incorrect torque values listed in Sec 6.1.3 step 17 and Sec
6.2.3 step 12

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SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
References
DOCUMENT TITLE
103272-000 SkyView HDX Aircraft Flight Manual Supplement
102949-003 SkyView HDX Pilot’s User Guide Dynon Document
103272-000 SkyView HDX Aircraft Flight Manual Supplement
103000-000 Dynon Servo Shear Screw Replacement Instructions
43.13-1B Acceptable Methods, Techniques and Practices- Aircraft Inspection and Repair
43.13-2B Acceptable Methods, Techniques and Practices- Aircraft Alterations
Cessna Model 172 Maintenance Manual

SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
Page | iii
Table of Contents
1Introduction.............................................................................................. 1
1.1 Product Registration..................................................................................................... 1
1.2 Using this Manual......................................................................................................... 1
1.3 Manual Conventions..................................................................................................... 1
1.4 Installation Compliance ................................................................................................ 2
1.5 Installation Record........................................................................................................ 2
2Materials ................................................................................................... 3
2.1 Roll Servo Installation Materials ................................................................................... 3
2.2 Pitch Servo Installation Materials.................................................................................. 4
3Roll Servo Mounting Bracketry Installation ........................................... 6
3.1 Location and Access .................................................................................................... 6
3.2 Bracket Positioning and Temporary Installation ........................................................... 6
4Pitch Servo Mounting Bracketry Installation.......................................... 8
4.1 Location and Access .................................................................................................... 8
4.2 Base Bracket and Angle Brace Positioning and Temporary Installation....................... 8
4.3 Vertical Bracket Positioning and Temporary Installation............................................... 9
4.4 Mounting Bracket Final Assembly ................................................................................ 9
4.5 Sway Brace Final Assembly....................................................................................... 10
5Servo Electrical Wiring .......................................................................... 11
5.1 Wire Harness Preparation .......................................................................................... 11
5.2 Wire Harness Routing ................................................................................................ 11
5.3 Electrical Connection.................................................................................................. 12
6Continued Airworthiness....................................................................... 13
6.1 Roll Servo Removal and Installation........................................................................... 13
6.2 Pitch Servo Removal and Installation......................................................................... 16
6.3 Servo Calibration Procedure ...................................................................................... 18
6.4Servo Test Procedure................................................................................................. 18
7Figures.................................................................................................... 19
7.1 Roll Servo Parts and Assemblies ............................................................................... 19
7.2 Roll Servo Installation................................................................................................. 23
7.3 Pitch Servo Parts and Assemblies.............................................................................. 31

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SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
7.4 Pitch Servo Installation............................................................................................... 35

SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
Page | 1
1 Introduction
This manual provides instructions to install, configure, and maintain SkyView HDX System
autopilot servos in unmodified Cessna 172 Model Series F–S airplanes. Any airplane
configurations that require modifications to areas in the airplane where autopilot servos are
installed are not addressed in this manual.
The SkyView HDX System autopilot servo settings are available for download as a configuration
file that is loaded into the SkyView HDX display unit. The file configures the autopilot servo
performance settings to meet the applicable certification regulations. Configuration files are
available for download at www.dynon.aero/stcdocs.
1.1 Product Registration
Register your products at http://register.dynonavionics.com. Registering your SkyView HDX
equipment verifies ownership, expedites warranty claims, and allows Dynon Avionics to notify
you when product Service Bulletins and Technical Advisories are published. You can also sign
up to receive news and product announcements from Dynon Avionics. Dynon Avionics will not
share your contact information with third-parties or send you announcements without your
explicit consent.
1.2 Using this Manual
To reduce paper usage, Dynon Avionics does not provide a printed version of this manual.
However, Dynon Avionics grants permission to third parties to print this manual as necessary.
The most recent PDF version is available for download at www.dynon.aero/stcdocs. This
document is updated periodically, and it's important to use the most recent version when
installing SkyView HDX System components.
Dynon Avionics suggests keeping a PDF version of the manual on your smartphone, tablet, or
laptop computer while installing SkyView HDX System components. Using the manual
electronically allows you to view figures in color, perform keyword searches, and quickly navigate
the document.
1.3 Manual Conventions
This manual uses the following iconography:
Alerts reader to potential injury or equipment damage.
Alerts reader to important information.
Alerts reader to helpful tips or suggestions.

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SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
1.4 Installation Compliance
Airplanes on the AML meet a minimum required configuration for applicability of the STC.
However, some airplanes may have been modified, and consequently, it may be difficult to use
the information in this manual to completely substantiate the installation in compliance with the
STC. It is the installer's responsibility to make the final determination of applicability for each
individual airplane.
Prior to completing the installation, and before returning the aircraft to service, the installer must
complete and submit a completed FAA Form 337 Major Repair & Alteration (Airframe,
Powerplant, Propeller, or Appliance) to the appropriate FAA Flight Standards District Office. The
form must include the following:
•Description of the SkyView HDX System installation.
•Description of how the SkyView HDX System interfaces with existing equipment and
systems.
•Appropriately approved or acceptable data that demonstrates compliance.
Refer to AC 43.9-1E - Instructions for Completion of FAA Form 337 for additional information.
1.5 Installation Record
It is the responsibility of the mechanic or facility performing the installation to record where each
module of the SkyView HDX System has been installed in the airplane. This documentation
should be entered into airplane’s permanent record. Dynon Avionics provides a document
template to record this information. Download the document (103777-000 SkyView HDX System
Equipment Installation Record) at www.dynon.aero/stcdocs.

SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
Page | 3
2 Materials
This section provides information aboutthe materials used in installation of Roll and Pitch servos
in unmodified Cessna 172 Model Series F–S airplanes.
2.1 Roll Servo Installation Materials
The materials identified in Table 1 are required to install the Roll servo. Item numbers are used
as figure call-outs in Section 7.1 Roll Servo Parts and Assemblies and Section 7.2 Roll Servo
Installation.
Table 1: Roll Servo Installation Materials
ITEM
DYNON PART
DESCRIPTION
QTY
1
503406-000
SV42C SERVO ASSEMBLY
1
1-1
SERVO SHEAR SCREW
1
1-2
AN310-5 NUT CASTLE 5/16"-24
1
1-3
WASHER WAVE STL 5/16"
1
1-4
WASHER FLAT NYLON 5/16"
1
1-5
SERVO CAPSTAN
1
1-6
PHIL PAN HD SCREW #6-32 X 1/4"
4
1-7
MS35333-37 WASHER STAR STL #6
4
1-8
MS24665-210 COTTER PIN
1
1-9
BRIDLE CABLE GUARD
1
2
503508-000
SERVO MOUNTING KIT C172
*
2-1
503107-000 or -001
ROLL SERVO UPPER BRACKET C172
1
2-2
503108-000 or -001
ROLL SERVO LOWER BRACKET C172
1
3
103664-000
ROLL SERVO HARDWARE KIT C172
1
3-1
AN525-832R8 SCREW WASHER HEAD #8-32
10
3-2
AN960-08 WASHER FLAT STL #8
10
3-3
AN365-832A NUT LOCK STL #8-32
10
3-4
AN3H-3A BOLT HEX #10-32 DRILLED HEAD
4
3-5
MS35333-39 WASHER LOCK STAR INT STL #10
8
3-6
AN960-10 WASHER FLAT STL #10
8
4
503674-000
SERVO CAPSTAN ACCESSORY KIT 1/8"
1
4-1
AN365-1032A NUT LOCK STL #10-32
4
4-2
AN960-10-3 WASHER FLAT STL #10
4
4-3
AN3H-6A BOLT HEX #10-32 DRILLED HEAD
4
4-4
BRIDLE CABLE 1/16" DIA
1
4-5
SWAGE STOP FOR CABLE 1/16" DIA
2
4-6
BRIDLE CABLE CLAMP 1/8" 1/16" DIA
4
* Kit shared with pitch servo assembly.

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SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
2.2 Pitch Servo Installation Materials
The materials identified in Table 2 are required to install a Pitch servo. Item numbers are used
as figure call-outs in Section 7.3 Pitch Servo Parts and Assemblies and Section 7.4 Pitch Servo
Installation.
Table 2: Pitch Servo Installation Materials
ITEM
DYNON PART
DESCRIPTION
QTY
1
503406-000
SV42C SERVO ASSEMBLY
1
1-1
SERVO SHEAR SCREW
1
1-2
AN310-5 NUT CASTLE 5/16"-24
1
1-3
WASHER WAVE STL 5/16"
1
1-4
WASHER FLAT NYLON 5/16"
1
1-5
SERVO CAPSTAN
1
1-6
PHIL PAN HD SCREW #6-32 X 1/4"
4
1-7
MS35333-37 WASHER STAR STL #6
4
1-8
MS24665-210 COTTER PIN
1
1-9
BRIDLE CABLE GUARD
1
2
503508-000
SERVO MOUNTING KIT C172
*
2-3
503588-000
PITCH SERVO BASE BRACKET C172
1
2-4
503590-000
PITCH SERVO ANGLE BRACE C172
2
2-5
503589-000
PITCH SERVO VERTICAL BRACKET C172
1
2-6
503105-000
PITCH SERVO PULLEY BRACKET C172
1
2-7
MS20219-2 PULLEY PHENOLIC 1.75" OD BORE 0.25" ID
1
2-8
503329-000 or -001
PITCH SERVO LONG SWAY BRACE C172
1
2-9
503330-000
PITCH SERVO SMALL SWAY BRACE C172
1
3
103667-000
PITCH SERVO HARDWARE KIT C172
1
3-1
AN525-832R8 SCREW WASHER HEAD #8-32
29
3-2
AN960-08 WASHER FLAT STL #8
29
3-3
AN365-832A NUT LOCK STL #8-32
28
3-4
AN3H-3A BOLT HEX #10-32 DRILLED HEAD
4
3-5
MS35333-39 WASHER LOCK STAR INT STL #10
8
3-6
AN960-10 WASHER FLAT STL #10
8
3-7
AN4-11A BOLT HEX 1/4-28 1-5/32"
1
3-8
AN960-416 WASHER FLAT STL 1/4"
2
3-9
AN365-428A NUT LOCK STL #1/4-28
1
3-10
CCP-42 RIVET CHERRY N
4

SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
Page | 5
ITEM
DYNON PART
DESCRIPTION
QTY
3-11
MS20426AD3-4 RIVET ALUM 100° COUNTERSUNK
2
4
503674-000
SERVO CAPSTAN ACCESSORY KIT 1/8"
1
4-1
AN365-1032A NUT LOCK STL #10-32
4
4-2
AN960-10-3 WASHER FLAT STL #10
4
4-3
AN3H-6A BOLT HEX #10-32 DRILLED HEAD
4
4-4
BRIDLE CABLE 1/16" DIA
1
4-5
SWAGE STOP FOR CABLE 1/16" DIA
2
4-6
BRIDLE CABLE CLAMP 1/8" 1/16" DIA
4
* Kit shared with roll servo assembly.

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SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
3 Roll Servo Mounting Bracketry Installation
This section details how to assemble and temporarily install the Roll Servo mounting bracketry.
Refer to Section 6 Continued Airworthiness to remove or install a roll servo after bracket
installation is complete. Refer to Section 5 Servo Electrical Wiring for roll servo wiring
information.
Before installing a Roll Servo, verify the aileron control cables are rigged and
tensioned to the airplane manufacturer’s specifications.
Installers should consider printing the figures in Section 7.2 and keeping them on-
hand as they perform the installation.
There are two different sets of Roll Servo brackets for Cessna 172 Model Series F–S airplanes:
•Upper Bracket 503107-000 and Lower Bracket 503108-000
•Upper Bracket 503107-001 and Lower Bracket 503108-001
The -000 brackets attach the Roll Servo to the Left-Hand Direct (i.e. control) cable and the -001
brackets attach the Roll Servo to the Carry-Thru (i.e. balance) cable.
3.1 Location and Access
The Roll Servo is located in the left wing between the ribs at Wing Stations 100.00 and 118.00
(WS100.00 and WS118.00), aft of the rear spar (see Figure 5 and Figure 6). The location is
accessed through inspection hole 520AB (Cessna Identification #) on the underside of the left
wing, outboard of the flap and just forward of the aileron (see Figure 5). The aileron cables are
accessed through inspection hole 510NB (Cessna Identification #) on the underside of the left
wing, and just forward of the left flap (see Figure 5). The flaps need lowering to reach this
inspection hole.
3.2 Bracket Positioning and Temporary Installation
Complete the following to prepare the airplane for temporary installation of Roll Servo Brackets:
1. Locate three (3) rivets that attach upper wing skin to rear spar, immediately outboard of
WS100.00 rib (see Figure 7).
2. Drill out and remove three (3) rivets. Pilot drill (#30) holes.
3. Pilot drill (#30) two (2) new holes equally spaced between rivet holes (see Figure 7)
4. Locate three (3) rivets that attach lower wing skin to rear spar, immediately outboard of
WS100.00 rib (see Figure 8).
5. Drill out and remove three (3) rivets. Pilot drill (#30) holes.
6. Pilot drill (#30) two (2) new holes equally spaced between rivet holes (see Figure 8)

SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
Page | 7
Complete the following to position and temporarily install Upper and Lower Roll Servo Brackets:
1. Attach upper and lower brackets to roll servo (see Figure 4). Do not fully tighten
fasteners yet. Make sure upper bracket is in lowest (retracted) position allowed by its
mounting slots.
2. Using Figure 9 and Figure 10 as guidance:
•Insert servo/bracket assembly into wing through inspection hole 520AB.
•Raise upper bracket until bracket contacts upper rear spar flange.
•Position assembly by sliding it inboard so that roll servo brackets contact flange of
the inboard WS100.00 rib.
3. Make sure there is clearance to prevent brackets from chafing spar flange bend (see
Figure 11).
4. Make sure aileron cables do not interfere with roll servo or brackets.
5. Temporarily tighten servo bolts.
6. From outside airplane, use holes in wing skins as guides to match drill (#30) holes
through upper and lower brackets, installing cleco-type fasteners as you proceed.
7. Use #21 drill to finalize holes in brackets and wing skins, removing cleco-type fasteners
as you proceed. Deburr all holes.
8. Remove roll servo/bracket assembly from wing.
Mark edge of servo on upper bracket to simplify re-installation.
9. Install roll servo (see Section 6.1.3 Roll Servo Installation).

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SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
4 Pitch Servo Mounting Bracketry Installation
This section details how to assemble and install the Pitch Servo mounting bracketry. Refer to
Section 6 Continued Airworthiness to remove or install a Pitch Servo after bracket installation is
complete. Refer to Section 5 Servo Electrical Wiring for Pitch Servo wiring information.
Before installing a Pitch Servo, verify that the elevator control cables are rigged and
tensioned to the airplane manufacturer’s specifications.
Installers should consider printing the figures in Section 7.4 and keeping them on-
hand as they perform the installation.
4.1 Location and Access
The Pitch Servo is installed underneath the floor of the Aft Baggage Area (see Figure 18),
immediately behind bulkhead at Fuselage Station 108.00 (FS108.00). Remove the floor of the
Aft Baggage Area to access the Pitch Servo installation location.
4.2 Base Bracket and Angle Brace Positioning and Temporary Installation
Complete the following to position and temporarily install the Pitch Servo Base Bracket and Pitch
Servo Angle Braces:
1. Position base bracket into airplane (see Figure 19 and Figure 20).
2. Align base bracket longitudinally so that right-side forward edge of bracket is spaced
0.10" (min.) and 0.25" (max.) behind FS108.00 bulkhead (see Figure 19).
3. Align base bracket perpendicular to the FS108.00 bulkhead.
4. Position left and right angle braces against FS108.00 bulkhead and against base
bracket flanges (see Figure 19 and Figure 20).
5. Align base bracket laterally as required to prevent base bracket and left and right angle
braces from contacting cable pulley brackets attached to FS108.00 bulkhead (see
Figure 19).
6. Use base bracket pilot holes as guide to match drill (#40) pilot holes through airplane
skin, installing cleco-style fasteners as you proceed.
7. Use angle braces pilot holes as guide to match drill (#40) pilot holes through FS108.00
bulkhead, cleco-style fasteners as you proceed.

SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
Page | 9
4.3 Vertical Bracket Positioning and Temporary Installation
Complete the following to assemble, position, and temporarily install the Pitch Servo Vertical
Bracket Assembly:
1. Temporarily attach pitch servo, idler pulley, and pulley guard to vertical bracket (see
Figure 21).
2. Position vertical bracket assembly so that lower flange of vertical bracket rests on base
bracket (see Figure 22).
3. Longitudinally position assembly on pitch servo base bracket so that forward edge of
servo capstan maintains a minimum of 0.25" longitudinal spacing from elevator control
cable pulleys mounted to FS108.00 bulkhead (see Figure 22 and Figure 23).
4. Laterally position assembly on pitch servo base bracket as required to align idler pulley
with lower elevator control cable (see Figure 22 and Figure 23). Ensure no components
interfere with elevator and elevator trim control cables.
5. Once positioned, use vertical bracket pilot holes as guide to match drill (#40) pilot holes
through base bracket, installing cleco-style fasteners as you proceed.
Match drill a minimum of two pilot holes to position the Pitch Servo Vertical Bracket
Assembly.
4.4 Mounting Bracket Final Assembly
Complete the following to permanently attach the Pitch Servo Vertical Bracket Assembly to the
Base Bracket to make the Pitch Servo Bracket Assembly:
1. Loosen vertical bracket assembly from base bracket, and then remove vertical bracket
assembly from airplane.
2. Disassemble vertical bracket assembly.
3. Loosen base bracket and angle braces from airplane skin and FS108.00 bulkhead, and
then remove base bracket and angle braces from airplane.
4. On a bench, attach vertical bracket to base bracket with cleco-style fasteners.
5. Use #21 drill to finalize holes in vertical bracket and base bracket, removing cleco-style
fasteners as you proceed. Deburr all holes.
6. Permanently secure vertical bracket to base bracket using screws, washers, and nuts
(see Figure 24).
7. Permanently secure idler pulley and pulley guard to vertical bracket (see Figure 21).

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SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
Complete the following to permanently install the Pitch Servo Bracket Assembly in the airplane:
1. Position pitch servo bracket assembly in airplane, and then attach with cleco-style
fasteners
2. Position left and right angle braces against base bracket flanges and FS108.00
bulkhead, and then attach with cleco-style fasteners.
3. Use #21 drill to finalize holes in base bracket flanges, angle brace lower flanges, and
airplane skin, removing cleco-style fasteners as you proceed. Deburr all holes.
4. Use #30 drill to finalize holes in angle brace upper flanges and FS180.00 bulkhead,
removing cleco-style fasteners as you proceed. Deburr all holes.
5. Re-position pitch servo bracket assembly in airplane, and then attach with cleco-style
fasteners in every other hole.
6. Secure angle braces to FS180.00 bulkhead with (4) CCP-42 rivets. Rivet left angle
brace from front of FS180.00 bulkhead and right angle brace from rear of FS180.00
bulkhead.
7. Permanently secure pitch servo bracket assembly to airplane skin using screws,
washers, and nuts (see Figure 25).
4.5 Sway Brace Final Assembly
Complete the following to permanently install the Pitch Servo Sway Braces:
1. Temporarily install pitch servo to pitch servo bracket assembly with (3) AN3 bolts (see
Figure 21).
2. Temporarily install short sway brace to pitch servo with (1) AN3 bolt (see Figure 26).
3. Position long sway brace between FS180.00 bulkhead rib and short sway brace (see
Figure 27). This determines final length of long sway brace.
4. Mark and trim long sway brace (see Figure 27).
5. Temporarily fasten long sway brace to short sway brace with (1) AN3 bolt (see Figure
26).
6. Drill (#40) two pilot holes through FS180.00 bulkhead rib flange and long sway brace
(see Figure 27), installing cleco-style fasteners as you proceed.
7. Use a #30 drill to finalize holes in FS180.00 bulkhead rib flange and long sway brace,
removing cleco-style fasteners as you proceed. Deburr and dimple all holes.
8. Loosen long sway brace from short sway brace. Short sway brace remains on servo.
9. Permanently secure long sway brace to FS180.00 bulkhead rib flange with (2)
MS20426AD3-4 rivets.
10. Loosen pitch servo from bracket assembly and remove from airplane.
11. Install pitch servo (see Section 6.2.3 Pitch Servo Installation).

SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
Page | 11
5 Servo Electrical Wiring
This section provides details about the electrical installation of autopilot servos.
Dynon Avionics offers a wire harness kit (SV-NET-SERVO) to simplify the process of electrically
connecting autopilot servos to the SkyView HDX Network and airplane power. Contact Dynon
Sales for more information.
If your SkyView HDX System installation requires customized wire harnesses, refer
to the Skyview HDX Electrical Schematic Diagram and SkyView HDX Wiring
Harness Reference documents at www.dynon.aero/stcdocs for additional electrical
connection information.
5.1 Wire Harness Preparation
Table 3 provides wire/pin connection information for preparing an autopilot servo wire harness.
Table 3: Autopilot Servo Harness, Pin/Wire Connections
D9 Harness
Pin #
D9 Harness
Wire Function
D9 Harness
Wire Color
Connection / Notes
1
SkyView Network Data 1A
Green
SkyView Network D9 Connector, Pin 1
2
Ground
Black
Common Airframe Ground
3
Autopilot Disconnect
Yellow
A/P DISC Button
4
SkyView Network Data 2B
White w/ Blue
SkyView Network D9 Connector, Pin 4
5
None
No Wire
No Connection
6
SkyView Network Data 1B
Blue
SkyView Network D9 Connector, Pin 6
7
Power
Red
Electrical Bus
Use 10A Circuit Breaker / Fuse
8
SkyView Network Data 2A
White w/ Green
SkyView Network D9 Connector, Pin 8
9
None
No Wire
No Connection
To prepare an autopilot servo wire harness:
1. Connect included D9M connector to servo wires; connect included D9F connector to
one end of wire bundle. Close connector shells.
2. Connect D9M and D9F connectors together.
5.2 Wire Harness Routing
Route Roll Servo harness wires through left wing, into cabin, and toward instrument panel. Route
Pitch Servo harness wires through fuselage, under cabin floor, and toward instrument panel.
Wires connect as follows:
•Green (pin 1), white/blue (pin 4), blue (pin 6), and white/green (pin 8) wires to a SkyView
HDX Network device or hub.
•Red (pin 7) wire to Autopilot Power (A/P POWER) switch on instrument panel.

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SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
•Black (pin 2) wire to common airframe ground.
•Yellow (pin 3) wire to Autopilot Disconnect (A/P DISC)button on instrumentpanel or yoke.
Secure wires to ensure they do not chafe or interfere with the airplane's flight
controls or other moving components.
5.3 Electrical Connection
To connect an autopilot servo to the airplane's electrical system:
1. Make sure airplane power is disconnected.
2. Install dedicated 10A circuit breaker or replaceable fuse and connect to electrical bus.
See airplane manufacturer's documentation for guidance on connecting circuit breakers
and replaceable fuses.
3. Install A/P POWER switch on instrument panel.
Power for all autopilot servos must be controlled by a switch prominently mounted
on the instrument panel. This provides the pilot the ability to quickly turn off power
to the servos should it be necessary.
4. Connect red (pin 7) wire to A/P POWER switch; connect black (pin 2) wire to common
airframe ground. Use insulated connectors.
Ground connection must be common with all devices that interface with the SkyView
HDX System.
To connect an autopilot servo to the SkyView HDX Network:
1. Make sure airplane power is disconnected.
2. Terminate green (pin 1), white/blue (pin 4), blue (pin 6), and white/green (pin 8) wires
to same pins on included D9F connector. Close connector shell.
3. Connect D9F connector on harness to SkyView HDX Network hub.
To connect an autopilot servo to an A/P DISC button:
1. Make sure airplane power is disconnected.
2. Connect yellow (pin 3) wire to A/P DISC button. Use insulated connectors or splices.

SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
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6 Continued Airworthiness
This section provides detailed Continued Airworthiness information for SkyView HDX autopilot
servos.
6.1 Roll Servo Removal and Installation
This section details how to remove and install a Roll Servo.
Before installing a Roll Servo, verify the aileron control cables are rigged and
tensioned to the airplane manufacturer’s specifications.
Installers should consider printing the figures in Section 7.2 and keeping them on-
hand as they perform removal and installation.
6.1.1 Location and Access
The Roll Servo is located in the left wing between ribs at Wing Stations 100.00 and 118.00
(WS100.00 and WS118.00), behind the rear spar (see Figure 5 and Figure 6). The Roll Servo
location is accessed through inspection hole 520AB (Cessna Identification #) on the underside
of the left wing, outboard of the flap and just forward of the aileron (see Figure 5). The aileron
cables are accessed through inspection hole 510NB (Cessna Identification #) on the underside
of the left wing, and just forward of the left flap (see Figure 5). The flaps need lowering to reach
this inspection hole.
6.1.2 Roll Servo Removal
Complete the following to remove a Roll Servo:
1. Lower airplane flaps.
2. Remove access covers 520AB and 510NB (see Figure 5).
3. Disconnect D9M and D9F connectors from autopilot servo wire harness.
4. Mark location of bridle clamps on cables to simplify re-installation.
5. Remove cable clamps that connect bridle cables to aileron control cable.
6. Remove fasteners that secure brackets to rear spar flanges and airplane skins (see
Figure 11).
7. Remove roll servo/bracket assembly from airplane (see Figure 9 (reverse order)).
Mark edge of servo on upper bracket to simplify re-installation.
8. Cut safety wire and remove roll servo from upper and lower brackets (see Figure 4).

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SkyView HDX System Autopilot Servo Installation & Maintenance Manual - Cessna Models 172 F-S, Revision D
6.1.3 Roll Servo Installation
Complete the following to install the Roll Servo:
Before installing a Roll Servo, verify the aileron control cables are rigged and
tensioned to the airplane manufacturer’s specifications.
1. Attach upper and lower brackets to roll servo (see Figure 4). Attach upper bracket to roll
servo using marks made during temporary installation or removal.
2. Torque bolts that secure roll servo to brackets to 20–25 inch-pounds, and then safety
wire bolts.
3. Insert roll servo/bracket assembly into left wing through access hole 520AB (see Figure
9).
4. Verify aileron cables do not interfere with roll servo or brackets.
If -000 brackets are installed, verify that forward aileron cable is aligned with center
of servo capstan.
If -001 brackets are installed, verify that rear aileron cable is aligned with center of
servo capstan.
5. Align lower bracket holes with common holes in lower rear spar flange and airplane
skin, and then temporarily fasten lower bracket to lower rear spar flange and airplane
skin using screws, washers, and nuts (see Figure 11).
6. Align upper bracket holes with common holes in upper rear spar flange and airplane
skin, and then permanently secure upper bracket to upper rear spar flange and airplane
skin using screws, washers, and nuts (see Figure 11). Do not fully tighten fasteners ye
7. Permanently secure lower bracket to lower rear spar flange and airplane skin using
screws, washers, and nuts (see Figure 11).
8. Re-connect D9M and D9F wire harness connectors, and if needed, re-secure harness
to airframe.
9. Center ailerons using control yoke.
10. Rotate capstan until swage hole points to 6 o'clock (see Figure 12).
11. Once swage hole is located, pass one end of cable underneath a cable guard flange so
that cable sits in the center groove (see Figure 12).
12. Set cable swage into swage hole and pass the other end of the bridle cable under the
opposite cable guard flange (see Figure 12 and Figure 13).
13. Following grooves, feed both cable ends around capstan and underneath next set of
cable guard flanges (see Figure 12 and Figure 13). Capstan may need to be rotated to
expose swage hole if it is underneath a cable guard flange.