Learjet 60 - Rudder Boost Switch; Rudder Boost System

Learjet 60

Pilot's Manual
RUDDER BOOST SYSTEM
The rudder
boost system is installed to provide reduced rudder pedal
force, increased directional
control effectiveness and improved take-
off performance . With the rudder
boost on, minimum control speed-
ground (VMCG), takeoff speeds
and distances are all lower . Rudder
boost
is a function of the autopilot
. In addition to the autopilot, the
system consists of a yaw force
interface box, force sensors, flap posi-
tion switch, RUDDER BOOST
Switch,
and
associated aircraft wiring .
The yaw damper servo provides the "boost"
to assist the pilot in mov-
ing the rudder in the desired direction . The
rudder boost system is
supplied 28 VDC through the 3-amp FD 1 circuit
breaker on the pi-
lot's
circuit breaker panel .
Normally the RUDDER BOOST Switch, on the
pilot's switch panel, is
left on
at all times . With flaps lowered more than 3°,
applying approx-
imately
50
pounds of force to either rudder
pedal will cause the yaw
servo to automatically engage and apply force to
the rudder in the
same
direction as the pilot . As pilot input
force is increased, the servo
force will also increase up to the
maximumyaw servo force . When
the rudder boost engages, the green
RB annunciator, on the FCP,
illu-
minates to indicate rudder
boost is active . If the yaw
damper is on
when the rudder boost
engages, the system will make a
smooth tran-
sition from yaw damper to rudder
boost . A failure of the
system is in-
dicated by illumination of
the amber RB annunciator
on the FCP . Self-
test of the system
is initiated during system
power-up .
RUDDER BOOST
SWITCH
Arming of the
rudder boost system is
controlled by the RUDDER
BOOST Switch
located on the pilot's switch
panel . When the switch
is
set to ON, the
system will be armed . Setting
the switch to OFF
will
disarm the system
and the amber RB
annunciator, on the FCP, will
illuminate .
PM-123

5-59
Original