Learjet 60 - Page 146

Lealet 60
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Pilot's Manual
On aircraft
60-079, &
60-094 and subsequent and prior
aircraft modified by
SB
60-27-6, the autospoiler
mode
is used
to
automatically extend the
spoilers on landing or in W
event
of an aborted takeoff . When the
SPOILER lever is set to ARM, the system will be armed (SPOILER ARM
light will illuminate) to automatically extend both spoilers when one of
the following conditions are met .
Once spoilers are deployed, the deploy signal will latch and cycling the
squat switches
will
not stow the spoilers . Advancing one or both throt-
tles will release the latch and stow the spoilers . Normal spoiler exten-
sion and retraction
will override the autospoiler logic . Flap position has
no effect on autospoiler operation
and
autospoitars are not operational
when EXT or RET is selected . Autospoiler control circuits operate on 28
VDC supplied through the 3-amp SPOILER circuit breaker on the copi-
lot's circuit breaker panel . Autospoilers are operative during the EMER
BUS mode,
Normal Spoiler Mode : During the spoiler mode, the spoilers are sym-
metrically
extended and retracted through the SPOILER lever on the
forward
pedestal . In
flight, the
spoilers may be
extended
to any desired
position by placing the SPOILER lever in any position between ARM
and EVE Detents for approximately 10' and 20' positions are provided
between the ARM and EXT positions of the lever . On the ground, the
spoilers will extend fully whenever any partial
extension is selected .
Spoiler position is indicated by the spoiler position indicator adjacent
to the flap position indicator on the center instrument panel . The spoil-
er mode, when selected, will override the aileron augmentation (spoi-
leron) mode, if aileron augmentation is engaged . When the spoiler
lever
is positioned for spoiler extension, a computer-amplifier will
command a selector valve and two servo valves to the extend position .
PM-123
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45
Change 4
Flight Phase Autospollers will deploy when :
Aborted Tak Aircraft accelerates to 40 knots or greater groundspeed
and the thrust levers are brought to IDLE per the
ABORTED TAKEOFF
procedure . Spoilers
will remain
deployed unless a thrust lever is advanced above
IDLE .
Landing Either of the following occurs :
1 , Both squat switches indicate an "on ground" condi-
tion and both thrust levers are in IDLE (one may be
in CUTOFF) or
2 . A wheel speed of 40 knots or greater is attained at
touchdown and both thrust levers are in IDLE (one
may be in CUTOFF) .
Spoilers will remain deployed unless a thrust lever is
advanced above IDLE .