GFC 500 Autopilot with ESP Part 23 AML STC Maintenance Manual
Page 5
190-02291-01
Revision 1
2. System Description
2.1 Equipment Descriptions
2.1.1 GMC 507 Autopilot Mode Controller
The GMC 507 Autopilot mode controller is shown in Figure 2 1. The switches on the front panel
of the GMC 507 provide inputs to the G5 instrument and GSA 28 servos for flight director
computations. The GMC 507 also contains some of the system monitoring and audio functions
for the system.
Refer to the
G5 Electronic Flight Instrument Pilot’s Guide for Certified Aircraft, 190-01112-12 for
operational characteristics of the system.
Figure 2-1
– GMC 507
2.1.2 GSA 28 Servo
The GSA 28 is a smart servo. The autopilot, trim and ESP algorithms are performed by the
servo. The motor in the GSA 28 servo is a brushless DC motor. This brushless DC motor has
an inherent safety feature in that it cannot drive by itself and requires software commutation to
run. The brushless DC motor also has a lower backdrive friction than brushed motor or
steppers motors. The GSA 28 is limited to a maximum of 60 in-lbs of torque.
GFC 500 Autopilot systems may have up to three servos (pitch, roll, and pitch trim). The pitch
trim servo is optional and may not be available on all airframes. Most installations will use bridle
cables attached to the primary flight control cables using clamps. New servo brackets, servo
bridle cables, and clamps are installed by this STC.
2.1.3 Audio Output
The GMC 507 provides an analog audio output to an audio panel, plus an active low output to
drive an external aural alert device (e.g. sonalert). The analog audio can be interfaced to any
audio panel that has an unswitched and unmuted analog audio input. If no existing audio panel
is interfaced, a sonalert is required.
Summary of Contents for GFC 500
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