Table of Contents
Advertisement
FLIGHT GUIDANCE SYSTEM
The aircraft flight guidance system consists of
a fail-operational automatic flight control sys-
tem (AFCS) (Figure 16-67) that provides au-
topilot functions throughout most phases of
flight. Redundant flight control functions pro-
vide the fail-operational capability with com-
parison information shared between multiple
systems. The AFCS consists of (Figure 16-58):
• Dual flight guidance computer
• Flight guidance controller
• Advisory display
• Turn and pitch controller
• Test functions
• AFCS operation
The AFCS provides automatic control over
the entire flight envelope using advanced con-
trol laws to enhance system performance.
Some of these control laws include the fol-
lowing:
• Three-axis accelerometer data from dual
IRS is extensively used to improve flight
guidance accuracy. Flight path errors
due to windshears are reduced using this
technique.
• Flight path guidance limits are pro-
grammed so that the autopilot can always
start and hold desired maneuvers with-
out exceeding comfortable forces and
roll rates.
• The digitally implemented control laws
are structured such that turns will not
destabilize any of the vertical modes
(e.g., in the ALT HOLD mode, there
will be no gain or loss of altitude dur-
ing a rolling maneuver).
• Servo torques and trim rates are con-
tinuously programmed as a function of
flight condition to provide increased
CL-600-2B16 PILOT TRAINING MANUAL
No single failure will prevent the continued
normal safe operation of the DAFCS system.
When a system failure is detected, the failed
FGC is isolated from the system or the oper-
ating flight guidance computer may disen-
g a g e , a l l o w i n g t h e a l t e r n a t e F G C t o
automatically assume control of the aircraft.
This is accomplished without the loss of the
active flight guidance mode or a deviation
from the flight path.
This capability is possible because one flight
control computer is active and the other is in
standby. The FGC which is acting as the
standby, however, is doing all the same com-
putations as the active FGC. It is receiving the
same data from all sensors just as the active
FGC, and it is solving the same control equa-
tions for the same guidance mode as its coun-
terpart. If the active FGC should fail and
disengage, the alternate FGC immediately and
automatically picks up where the failed unit
stopped. The aircraft continues on its selected
flight path, and the pilot is advised by a sta-
tus message on the advisory display unit.
Flight Guidance Computer
The flight guidance computers (FGC 1 and 2)
provide independent autopilot, flight director,
and yaw damper control. The FGCs process
aircraft attitude information from the IRS and
produce pitch and roll flight director (FD)
steering commands for EADI display. The
FGCs provide autopilot pitch and roll control
outputs and yaw dampening for directional
stability.
The FGCs integrate the ADS, IRS, EFIS, FMS,
and MFD systems to gather aircraft informa-
tion. Normally, the pilot FGC 1 controls the
autopilot and FD functions. The copilot FGC
FOR TRAINING PURPOSES ONLY
FlightSafety Canada
controllability and stability in all flight
regimes.
• Servo torques are also programmed as
a function of flight condition to result
in minimum stick movement into a
mistrim condition following an autopi-
lot disconnect.
L t é e
L t d .
CL 601-3A/R 16-61
Advertisement
Chapters
Table of Contents
