Learjet 60 - Emergency Braking; PARK BRAKE Light

Pilot's Manual
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Learjet 60
PARK BRAKE LIGHT
An amber
PARK BRAKE light, on
the pilot's subpanel, immediately
above the
ANTI-SKID lights, is
installed to alert the operator that the
parking
brake may be engaged .
The light is operated by a switch at-
tached
to the parking
brake valve and will be illuminated
whenever
power is on the aircraft and
the PARKING BRAKE handle is not
full
in .
EMERGENCY BRAKING
In the
event of a main hydraulic
system failure, the
wheel brakes can
be
applied pneumatically
. Emergency (pneumatic)
braking is initiated
and controlled through
the red EMER BRAKE handle
located on the
pedestal to the left of
the thrust levers . Emergency
braking is initiated
by pulling the handle
out of the recess and
pushing down . As the
EMER BRAKE handle is
pushed down, air
pressure from the BRAKE
AIR emergency air
bottle is directed to the
wheel brake shuttle valves
through the lever
actuated emergency
brake valve . If the emergency
air
pressure is greater than the
brake system pressure, the wheel
brake shuttle valves will reposition
to admit air pressure to apply
the
brakes . As
the brake handle is released,
excess air will be vented
over-
board and
the brakes will release .
Because the emergency air lines
are
plumbed
into the hydraulic brake system
between the anti-skid
con-
trol valves
and the wheel brakes,
anti-skid protection is not available
when
using emergency brakes . Also, the
parking brake will be inoper-
ative
when
using
emergency air pressure
.
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PM-123
Original