PRIMUS
r
1000 Integrated Avionics System
A28--1146--112--00
2-3
System Description
FLIGHT GUIDANCE SYSTEM (FGS)
The flight guidance system includes the following components:
D
Inside the IAC
-
Flight guidance computer (No.1 IAC only)
-
System monitors
D
Guidance Controller
D
Autopilot Controller
D
Servo Motor (pitch/roll/yaw)
The No. 1 IAC flight guidance computer is the fail--passive driver for the
flight director, autopilot, and pitch trim. Comparator monitor circuits on
the pilot and copilot AHRS and servo command outputs, are used to
operate the system fail passively. Servo command outputs from a
computed servo model in all three axes are compared to actual
command. If the difference between commands exceeds certain
threshold values, the FGS is disconnected from the servos. Normal
flight guidance functions are computed based on the No. 1 AHRS.
Flight director operation also comes from the No. 2 IAC.
The guidance controller contains the autopilot (AP) engage, yaw
damper (YD) engage, and low bank switch. Either side’s PFD and flight
director can be coupled to the autopilot.
Mode annunciations are displayed on the guidance controller and on
the PFD. The flight director command bars on the PFD, follow flight
director commands to display visual guidance for the selected mode.
The navigation sensor used for the chosen mode is selected on the
display controller (DC), and is annunciated on the PFD.
The yaw damper executes basic yaw damper functions with or without
the autopilot. The yaw damper is active when either the YD or AP
engage buttons on the autopilot controller is pushed.
The autopilot controller is used to manually control other autopilot,
using the PITCH wheel and TURN knob.
