Learjet 60 - Autopilot;Flight Guidance Mode Selection

Pilot's Manual
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Learjet 60
YD - The
YD button is a momentary
push-on/push-off button
which is used
to engage the yaw
damper . When engaged, the
indica-
tor above
the YD button illuminates
. The yaw damper can
be disen-
gaged
by depressing the YD
button a second time or by
depressing
the
Control Wheel Master (MSW)
switch .
TURB - The
TURB button is a
momentary push-on/push-off
button
which is used
to select the autopilot
turbulence mode .
WhenTURB is
selected,
the autopilot will
provide softer responses in
the pitch and
roll
axis for flying through
turbulence . TURB is not
available during
flight director only operation
and is locked out in APPR
mode .
AUTOPILOT/FLIGHT
GUIDANCE
MODE SELECTION
All mode selection buttons
are the momentary
push-on/push-off
type . A light
above the mode selector
button will illuminate if
all con-
ditions for the mode
are satisfied . Any selected
mode can be cancelled
by selecting an incompatible
mode, depressing the mode
selector but-
ton
a second
time, or depressing the
FD CLEAR button (flight direc-
tor only) . Mode
selection and operation is
identical for the left and
right channels .
Attitude Hold -
When the flight director is
operating and no vertical
mode is selected,
pitch attitude hold will
automatically be active .
When the flight director
is operating and no lateral mode is
selected,
roll attitude
hold will automatically be
active . Although active, the
roll attitude hold
cannot be entered without the
autopilot first being
engaged in the roll
mode and then disconnected .
These modes are
used to maintain a reference pitch and
bank angle . The reference an-
gles may be
established by manually flying
the aircraft to the desired
pitch and bank angle
and depressing the SYNC button (on
the control
wheel) . When the SYNC button
is released, the flight director will
generate
commands to maintain the existing
pitch and roll attitude . If
the bank angle is less
than 5°, the flight director will command
head-
ing hold . The reference values may
be changed using the vertical and
lateral
command function of the control wheel trim switches .
HDG
(heading) - When HDG is selected, autopilot/flight director
commands are generated to
maneuver the airplane as necessary to fly
a heading by position of the heading "bug" on the PFD .
1/2 BANK - When 1/2 BANK is selected, the flight director reduces
its maximum
roll attitude command to one-half of the normal limit .
1/2 BANK may be engaged in conjunction with any lateral mode ex-
cept Approach .
1/2 BANK
is
automatically selected when the air-
plane's pressure altitude is at or above 41,500 feet . 1/2 BANK auto-
matically clears when the airplane descends below this altitude .
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PM-123
Change 2