Hawker 800 XP, Руководство по подготовке пилотов

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Should a failure occur that affects both com-
puters, e.g. an open winding in the servo motor,
the second computer will detect the failure
and the AFCS will disengage. The “AP DISC”
annunciator will turn on and the autopilot dis-
engage horn will sound for one second.
When both channels of the AFCS are operating
normally, failures of the pitch, roll, or yaw servo
controls cause the AFCS to transfer from the pri-
ority computer (channel) to the standby com-
puter and display a “L (R) FAIL” annunciation.
When only one computer is operational, failures
in the pitch and roll servo controls cause the au-
topilot to disengage. Failures in the yaw damper
servo control cause both the autopilot and the
yaw damper to disengage.
Failures of the servo controls prior to en-
gagement will result in a FAIL annunciation
when engagement is attempted.
Closure Monitors
The internal signals within the AFCS are mon-
itored in order to determine that the system is
correcting to remove errors. For example, the
roll attitude, roll rate, and servo rotation must
all be in the proper direction to correct for
any roll axis errors or the roll monitors will
trip. The DISENGAGE and FAIL annuncia-
tions are the same as mentioned in the Servo
Monitors above.
Mistrim monitors
Roll
The aileron servo current is monitored in order
to detect an out-of-trim condition in which
there is a steady state load on the aileron servo.
When a steady state load of significant mag-
nitude exists for 20 seconds the amber “AIL
TRIM L(R)” annunciator will turn on.
Pitch
The elevator servo is monitored to detect a long
term load on the servo. When this condition is
detected the “ELEV TRIM UP (DN)” annun-
ciator will turn on. This message may appear
momentarily during normal operation for ma-
neuvers which require large trim changes.
Sensor Data Monitors
Flagged Failures
AHRS/DADC
Both channels of the AFCS receive data from
both AHRS and from both DADC's. When both
AHRS are valid the AFCS uses data from both
AHRS to compute the aircraft control func-
tions. The DADC data is handled in much the
same manner with the exception that only one
DADC provides reference data for the VS
hold, FLC, ALT hold and ALT SEL functions.
The DADC being used follows the HSI SEL
arrows. Failure of one AHRS or one DADC
will not affect the AP or YD engage status.
Failure of one DADC will disengage any air
data mode if the failed DADC is on the side
indicated by the HSI SEI. arrow. That is, if the
HSI SEL arrow is pointing to the pilot's side,
the failure of the pilot's DADC will cause the
air data modes to disengage. Failure of the
copilot's DADC will have no effect on the
mode status.
Navigation Receiver Failures
VOR Mode
Loss of valid from the navigation receiver for
more than 30 seconds will cause the VOR
modes to disengage. While the aircraft is pass-
ing over a station the loss of the nav valid will
not cause the mode to disengage because the
radio information is considered unreliable and
is not used by the autopilot.
16A-11
FOR TRAINING PURPOSES ONLY
HAWKER 800 XP PILOT TRAINING MANUAL
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