Learjet 60 - BLEED AIR Switches - EMER Function; CABIN ALT HI Light; Cabin Altitude Warning Horn and Mute Function; SYSTEM TEST Switch - CABIN ALT Function

Pilot's Manual
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Learjet 60
BLEED AIR SWITCHES
-
EMER FUNCTION
The L
and
R BLEED AIR
switches may be used to
manually
activate
emergency pressurization
.
When a
BLEED AIR
switch is set to
EMER,
the respective bleed-air shutoff valve
will
close and emergency pressur-
ization
valve
will
be
energized
open and the high-stage bleed
air will
be shut
off .
To reset the emergency pressurization valve, reduce power
on the respective
engine
and set the
BLEED AIR
switch to
OFF .
CABIN ALTITUDE WARNING HORN
and
MUTE FUNCTION
A
cabin altitude aural
warning horn will
sound to alert the crew should
the cabin altitude reach 10,100 (±250) feet .
The horn
is controlled by an
output
from
the pressurization indicator
which
activates the
warning
horn
circuit .
The
cabin altitude
warning horn
circuit is tested through
the SYSTEM
TEST
switch on the instrument panel
. The
MUTE switch,
on
right
thrust lever knob, may be used to interrupt the
horn for
approximately 60 seconds
in
the event the
horn
sounds .
CABIN ALT HI LIGHT
On aircraft 60-271 and subsequent and prior aircraft modified by SB 60-31-1,
a red
CABINALT
HI
light will illuminate in
conjunction with the cabin
altitude altitude
warning horn
when the cabin altitude reaches 10,100
(±250) ft .
SYSTEM TEST SWITCH - CABIN ALT FUNCTION
The
rotary-type SYSTEM
TEST
switch on the instrument panel is used
to test the cabin altitude
warning
system
.
Rotating the switch to
CABIN
ALT
and depressing the switch
TEST
button
will
provide a ground
simulating
the 10,100-foot
trigger signal .
6- 30 PM-123
Change 5