Instruction Manual

Page 2-10 G1000 / GFC 700 System Maintenance Manual - 200/B200 Series King Air
Revision 8 190-00915-01
2.1.17 GSA 80 Servos and GSM 85A/86 Servo Gearboxes (4)
The Garmin GFC 700 AFCS uses GSA 80 high torque servos to automatically control aircraft pitch, roll,
yaw damper/turn coordination and pitch trim. The pitch trim variant of the GSA 80 is a high speed servo
actuator. The GSA 80 contains a motor-control and monitor circuit board, as well as a solenoid and a
brushless DC motor. The GSA 80 servo receives serial RS-485 data packets from the GIA 63Ws. The roll
servo is located in the forward cabin lower fuselage at F.S. 185. The pitch, yaw, and pitch trim servos are
located in the tail. Power to the servos is received from the avionics No. 2 bus. All servos mount to a
Garmin GSM 85A or GSM 86 Servo Gearbox. The GSM 85A/86 is responsible for transferring the output
torque of the GSA 80 servo actuators to the mechanical flight control surface linkage. The GSM 85A has a
slip clutch that can be adjusted to a desired torque value. The GSM 86 has a clutch cartridge that cannot be
adjusted to a different torque value.
Figure 2-17, Servo
2.1.18 Garmin G36 and 37 GPS/WAAS Antennas
This installation uses one G36 GPS/WAAS antenna and a G37 GPS/WAAS/XM antenna. The antennas are
located in the upper, forward cabin, at F.S. 152.
2.1.19 Signal Conditioner (2)
Each GEA 71 receives signals from its on-side engine turbine speed sensor, propeller speed sensor and fuel
flow sensors via a Meggitt (Vibro-Meter) Signal Conditioner. This unit converts the signals from the engine
sensors to a signal usable by the GEA 71. These units are installed behind the instrument panel. Electrical
power to the No. 1 Engine Signal Conditioner is provided from Dual Fed Bus No. 1 and to the No. 2 Engine
Signal Conditioner from Dual Fed Bus No. 2. Both signal conditioners will power-up immediately with
external or aircraft power or battery operation.
NOTE
On serial numbers BB-1484, 1486 and subsequent, the electrical system includes the L ENG
INSTR and R ENG INSTR buses which (after this STC) are powered from Dual Fed Bus
No. 1 and No. 2 respectively. On these aircraft, the No. 1 Engine Signal Conditioner
receives power from Dual Fed Bus No. 1 via the L ENG INSTR bus and the No. 2 Engine
Signal Conditioner receives power from Dual Fed Bus No. 2 via the R ENG INSTR bus.