AUTOFLIGHT, CAT II
Description
Aircraft Operations Manual
3.1
O
PAGE
6
Jun 01/19
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Report mode is the one of the three available
basic submodes that is to be notified.
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Available on ground only with AP and YD disen-
gaged but before power shut
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down.
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Diagnostics can be performed independently on
either left or right FCC channel and displayed on
the respective EFIS side.
2.
MAIN COMPONENTS AND SUBSYSTEMS
2.1
Flight Control Computer (FCC)
The FD/AP computer is the heart of the flight con-
trol system. The signals received from various other
systems are converted into command signals ac-
cording to the selected mode of operation.
Command signals are fed to the FD command bar
for display of pitch and roll steering. With the AP
engaged, identical signals are transformed for ac-
tuation of rudder, aileron and elevator servos and
also the pitch and rudder trim system. See Fig. 1,
FGAS
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system schematic.
2.2
Mode Select Panel (MSP)
There are two MSP’s, one for each FD channel,
located on each side of the glareshield panel. They
contain push buttons for selection of FD lateral and
vertical modes. All buttons except 1/2 BANK mode
have only on
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function, i.e a mode can only be de-
selected by selection of another mode. Half bank
mode (if installed) button has an on/off function.
Selecting a new mode on one side will also change
the opposite MSP to the same mode except when
leaving APPR for a new mode. 1/2 BANK will only
change bank mode on selected side and must thus
be selected on both MSP.
2.3
Autopilot Panel (APP)
Located on the pedestal. Contains engage/discon-
nect levers for AP and YD, a button for AP transfer
between the two FCC channels and controls for
heading and vertical speed changes.
2.4
NAV source selection
There are two navigation source selection push but-
tons with built in indicators (NAV S.L. and NAV
S.R.) on the glareshield panel. The push buttons
are used to couple left or right navigation source as
input to the FD/AP.
2.5
Altitude Preselector Alerter (APA)
The altitude preselect mode causes the system to
capture the altitude selected on the preselector/al-
erter. Any other vertical mode may be used prior to
altitude capture.
At capture, other vertical modes are cleared and
command signals are generated to level off the air-
craft at the selected altitude. For the altitude alert
function, see AOM 12/1.1, AIR DATA SYSTEM.
2.6
Vertical Navigation Indicator (VNI).
(If installed)
The Vertical Navigation Indicator/computer (VNI)
serves as a vertical speed indicator. In addition it
computes data for vertical navigation to be used by
the FCC.
he VNI can also be used in conjunction with the Alti-
tude Preselector for automatic capture of selected
altitude.
2.7
Loss of approach warning.
(If Mod 1790 SB SF340 34
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049 installed)
The autopilot system is provided with a ”loss of ap-
proach mode” warning which is only active on that
side to which the autopilot is coupled to and when
the aircraft radio height is between 90
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1000 ft. The
warning will disconnect the AP/YD and will activate
the ”cavalry charge” aural alert. This occurs if any
of the following criteria are met:
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AP built
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in test detects nonvalid APPR mode.
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Pilot deselects APPR mode.
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LOC frequency becomes changed to VOR fre-
quency when established on LOC and GS.