190-01115-01
G3X/G3X Touch Installation Manual - GSA 28 Installation
Rev. AC
Page 17-1
17 GSA 28 (AUTOPILOT SERVO) INSTALLATION
This section contains general information as well as installation information for the GSA 28 Servo
Actuator. Use this section to mount the GSA 28 unit.
Figure 17-1 GSA 28 Unit View
17.1 Equipment Description
NOTE
There is no TSO/ETSO applicable to the GSA 28.
The GSA 28 servo is an autopilot servo intended for use in non FAA certified aircraft, including light sport
and home-built aircraft. The servo is intended to be used as part of the G3X system.
The function of the GSA 28 is to drive a flight-control axis (pitch, roll) of the aircraft. The servo can also
be installed in the rudder control system to provide yaw damping. Trim servo drive support is available for
any axis. All configurations can be used with or without auto-trim in each axis.
•
Roll autopilot only
•
Pitch/roll autopilot
•
Pitch/roll autopilot with yaw damper
The GSA 28 servo features an advanced brushless DC motor and gearbox, with an engagement clutch to
allow for very low-friction operation of the aircraft flight controls with clutch disengaged. The GSA 28
performs continuous internal monitoring and fault detection, and can also safely be back-driven by the
pilot in the event of an engagement clutch fault condition. An advanced electronic slip clutch provides the
ability for the pilot to overpower the servo at a configurable torque threshold without requiring use of a
consumable shear pin or additional moving parts.
NOTE
The GSA 28 engagement clutch is actuated by an internal solenoid. An audible clicking
sound when the servo is engaged or disengaged is normal and expected.
Under normal conditions, the GSA 28 servo operates based on flight director commands from the G3X
display units (GDU 370/375/460/465). When used with an optional GMC 30X mode controller, the GSA
28 maintains a reversionary capability to engage and fly the aircraft in basic wings-level and altitude-hold
modes even if all GDU displays in the aircraft are unavailable.