Learjet 60 - Control Wheel Master Switches-Pitch Trim Function; Control Wheel Trim Switches-Pitch Function; Pedestal NOSE DN-OFF-NOSE up Switch

Pilot's
Manual

Learjet 60
CONTROL WHEEL TRIM
SWITCHES-PITCH FUNCTION
Each control wheel trim
switch is a dual-function (trim
and
trim
arm-
ing) switch which controls
primary pitch trim and
roll trim . One
switch
is located on the
outboard horn of each control
wheel . Each
switch has
four positions : LWD,
RWD,NOSE UP, and NOSE
DN . The
trim arming
button on top of the
switch must be depressed
for trim
motion to
occur . With the PITCH
TRIM selector switch in
the PRI po-
sition,
actuation of either switch to
NOSEUP or NOSE DN
will signal
the
primary motor in the
horizontal stabilizer pitch
trim actuator to
move
the stabilizer in the
appropriate direction .
Actuation of the pi-
lot's switch will override
actuation of the copilot's
switch . Actuation
of
either switch to any
of the four positions
(LWD, RWD, NOSE UP,
or NOSE DN) will
disengage the autopilot .
Actuation of either switch
to NOSE UP
or NOSE DN will resynchronize
the Mach trim comput-
er .
PEDESTAL
NOSE DN-OFF-NOSE UP
SWITCH
The NOSE DN-OFF-NOSE UP
switch, located on the pedestal
trim
control panel, controls
secondary pitch trim . The switch is
spring
loaded to the center
(OFF) position . With the PITCH TRIM
selector
switch in the SEC position,
actuation of the NOSE DN-OFF-NOSE UP
switch to NOSE DN or NOSE
UP will signal the secondary
motor of
the horizontal stabilizer pitch
trim actuator to move the
stabilizer in
the appropriate direction .
Actuation of secondary pitch
trim will dis-
engage the autopilot .
The Mach trim system is inoperative
when us-
ing secondary
pitch trim . With the PITCH TRIM selector
switch in the
PRI or OFF
position, this switch has no effect .
CONTROL WHEEL MASTER SWITCHES-PITCH
TRIM FUNCTION
A Control Wheel Master Switch (MSW) is located
beneath the control
wheel trim switch on the outboard horn of each
control wheel . In ad-
dition to the switches' other functions, either
Control Wheel Master
Switch (MSW), when depressed, will inhibit primary or secondary
pitch trim
. If the Control Wheel
Master Switch is used to inhibit pri-
mary pitch
trim, primary
pitch trim cannot
be
reactivated until the
Control Wheel
Master
Switch is released and the trim input
is re-
moved . Therefore, during the preflight check of the primary pitch
trim system, it is necessary to release the control wheel trim switch as
well as the Control Wheel Master Switch (MSW) to reset the system .
Secondary pitch trim, however, will be inhibited only as long as the
Control Wheel Master Switch
(MSW)
is held .
5-12
PM-123
Original