CAE SimuFlite Citation Bravo, Pilot Training Manual

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Avionics
Citation Bravo
Developed for Training Purposes
5B-57
September 2005
IC-600 Display Guidance
Computer Interface
The IC-600 DGC receives pitch,
roll, and yaw signals from the navi-
gation sensors, gyros, autopilot con-
troller, and flight director computer. It
takes these signals, performs computa-
tions, and sends driving signals to the
aileron, elevator, and rudder servos.
Pitch axis signals come from the flight
director, airspeed sensor, autopilot
controller, vertical gyro, and flap posi-
tion control switch. Roll axis signals
come from the vertical gyro, direc-
tional gyro, flight director, and autopi-
lot controller. Yaw axis signals come
from the directional gyro that provides
heading information.
Altitude information comes from the
MADC or a barometric switch in the
copilot's static system. The autopilot
uses the altitude information to enable
or disable torque switching. Torque
switching provides two distinct rates
of servo torque, depending on aircraft
altitude. With autopilot, torque switch-
ing occurs at 14,500 ft.
The IC-600 takes these signals and
compares the aircraft's actual attitude
to the desired attitude. It then com-
mands the servos that move the flight
controls to reposition the aircraft to
match the desired aircraft attitude.
Servo Motors
SM-200 Servos for the ailerons, ele-
vator, and rudder consist of a DC
motor-tachometer, clutch assembly,
synchro, and power gear train. Sig-
nals from the IC-600 DGC drive the
servo motor through cables to posi-
tion the control surface. A feedback
signal produced by the motor-
tachometer relays control surface
position information to the com-
puter. Once the control surface
reaches the commanded position, the
computer signals the motor to stop.
During autopilot engagement, the
electromagnetic clutch assembly
connects the servo motor to its out-
put shaft. With the autopilot disen-
gaged, the output shaft moves freely.
A servo amplifier within the IC-600
DGC provides torque limiting for
the servos. The limiter regulates the
power supplied by the autopilot
computer to the servo drive motor.
The crew can overpower the autopi-
lot through control wheel move-
ment. If a mechanical failure occurs,
the servo's clutch slips to allow nor-
mal control movement.
Operation
The autopilot provides pitch, roll,
and heading hold without inputs
from the flight director. The autopi-
lot maintains the pitch attitude once
it engages and when a vertical mode
disengages. The autopilot mode
annunciates pitch (PIT) and roll
(ROL) in the PFD. Normally, with-
out Touch Control Steering (TCS)
inputs, the autopilot rolls the aircraft
to a wings level attitude while the
aircraft is in a bank. If the aircraft is
in a bank of less than 6°, the autopi-
lot holds the heading indicated at AP
engagement.
If the aircraft is in a bank greater
than 6°, the autopilot holds the bank
angle. The autopilot also holds the
heading existing at lateral mode dis-
engagement and does not engage if
the TURN controller is out of the
center detente position.
With TCS, the pilot can maintain a
bank greater than 6° during autopilot
engagement by pressing the TCS but-
ton on the control wheel, engaging the
autopilot, and then releasing the but-
ton; the autopilot maintains the estab-
lished bank. TCS also allows
maneuvering without disengaging any
selected flight director modes.