Learjet 60 - Flap Selector Switch; Flaps

Learjet 60

Pilot's Manual
FLAPS
The hydraulically-actuated, electrically-controlled flap system
pro-
vides flap settings of UP W), 8°, 20°, and DN (40°) . The single-slotted
flaps are attached to the rear wing spar with tracks, rollers, and hing-
es .
The
flap selector switch controls
a solenoid-operated hydraulic
control
valve
that meters
hydraulic pressure to the flap actuators . The
actuators mechanically rotate
sectors attached to the flaps through ad-
justable push-pull tubes . Interconnecting
cables and pulleys syn-
chronize flap movement throughout
the range of travel . A flap posi-
tion switch is mechanically connected to
each flap sector . These
switches provide flap position information to the
landing gear warn-
ing, stall warning, spoiler warning, trim-in-motion
warning, spoile-
ron, and autopilot systems . A flap limit switch is
mechanically con-
nected to each sector to automatically maintain flap
position at the
selected setting . Overtravel, when the flaps
are fully extended, is me-
chanically prevented . The flap control
system operates on 28 VDC
supplied through the 3-amp FLAPS circuit
breaker on the copilot's
circuit breaker panel . The flaps are
operative during the EMER BUS
mode .
FLAP SELECTORSWITCH
The flap selector switch is located
on the right side of the pedestal
near the thrust levers . The
switch has four positions : UP, 8, 20,
and
DN . The switch handle is
shaped like an airfoil . When 8°
or 20° flaps
is selected, 28 VDC is
directed to the applicable (up or
down) sole-
noid of the flap control
valve . The flap control valve will
meter hy-
draulic pressure to
the
flap
actuators and move the
flaps in the de-
sired
direction . As the flaps approach within 1° of
the selected setting,
the applicable
flap limit switch will remove
power from the flap
con-
trol
valve solenoid and flap travel will stop
. When UP is
selected, 28
VDC is directed to the up
solenoid of the flap control
valve and the
flaps will move in the up direction .
When DN is selected, 28
VDC is
directed to the down solenoid
of the flap control
valve and the flaps
will move in the down
direction . When the flaps
reach full extension,
the "down" pressure
will remain to maintain
the flaps full down .
PM-123
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5-3
Original