CESSNA®
MODEL 525 (SERIALS -0685 AND -0800 AND ON)
MAINTENANCE MANUAL
GARMIN ELEVATOR AUTOPILOT SERVO ASSEMBLY - REMOVAL/INSTALLATION
1.
General
A.
This section gives the removal and installation procedures for the Garmin Elevator Autopilot Servo
Assembly. The Garmin Elevator Autopilot Servo Assembly includes the Garmin GSA 81 Elevator
Autopilot Servo Actuator and the Garmin GSM 86 Elevator Autopilot Servo Gear Box. For a general
description of the elevator autopilot function, refer to Auto Flight - General. For more detailed
maintenance data, refer to the GSM 86 Servo Gear Box Installation Manual P/N 190-00303-83 found
in the Supplier publication List.
2.
Tools and Equipment
A.
Refer to Chapter 22, Auto Flight - General Tools and Equipment.
3.
Garmin GSA 81 Elevator Autopilot Servo Actuator (Motor) Removal/Installation
A.
Remove the Elevator Autopilot Servo Actuator (Motor) (Refer to Figure 401).
(1) Remove the electrical power from the airplane.
(2) Disengage the Automatic Flight Control System (AFCS) circuit breaker on the right circuit breaker
panel in the cockpit.
(3) Open the tailcone baggage compartment door. Refer to Chapter 6, Dimensions and Areas -
Description and Operation.
(4) Remove aft baggage compartment panel 321AL to get access to the elevator autopilot servo
actuator. Refer to Chapter 6, Access Plates and Panels Identiication - Description and
Operation.
(5) Disconnect the electrical connector (JT311) from the elevator autopilot servo actuator electrical
connector.
(6) Remove the bolts and the washers that attach the elevator autopilot servo actuator to the elevator
autopilot servo gear box.
(7) Remove the elevator autopilot servo actuator from the elevator autopilot servo gear box and the
airplane.
(8) If necessary, use a clean, lint-free cloth and remove unwanted grease buildup from the elevator
autopilot servo actuator output gear.
(9) If the elevator autopilot servo actuator is not going to be installed immediately, put covers over
the openings to keep the elevator autopilot servo gear box and elevator autopilot servo actuator
clean.
B.
Install the Elevator Autopilot Servo Actuator (Motor) (Refer to Figure 401).
(1) Remove the protective covers from the elevator autopilot servo gear box and elevator autopilot
servo actuator openings.
(2) Apply a thin layer of Aeroshell 33MS grease or an equivalent to the elevator autopilot servo
actuator output gear. Refer to Chapter 22, Auto Flight - General.
(3) Put the elevator autopilot servo actuator in it's correct position on the elevator autopilot servo
gear box.
(4) Align the splines on the elevator autopilot servo actuator shaft with the splines in the elevator
autopilot servo gear box.
(5) Starting with two opposite corner bolts, tighten all bolts until 0.01 to 0.03 Inches (0.25 to 0.76
mm) from fully seated.
(6) Verify that the rudder autopilot servo actuator is still slightly loose relative to the rudder autopilot
servo gear box, ensuring there is still relative movement between the two units.
(7) Starting with two opposite corner bolts, torque all bolts from 25.00 to 40.00 inch-pounds (2.82
N-m to 4.51 N-m). Refer to Chapter 20, Torque Data - Maintenance Practices.
(8) Connect the electrical connector (JT311) to the elevator autopilot servo actuator electrical
connector.
(9) Engage the AFCS circuit breaker on the right circuit breaker panel in the cockpit.
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Page 401
© TEXTRON AVIATION INC.
Nov 22/2017
ICA-525-27-00005
Form 2261 Rev 1