Learjet 60 - Flap Position Indicator; Spoilers

Pilot's Manual
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Learjet 60
FLAP POSITION INDICATOR
The vertical-scale
FLAP position indicator, mounted in the center in-
strument panel, provides
the crew with visual indication of flap posi-
tion . The indicator face consists
of a scale, which has markings for UP
(0°), 8°, 20°, and DN (40°), anda pointer on the right margin
of the scale .
A
potentiometer connected to the left flap sector transmits the flap
po-
sition signal
to the indicator . The indicator operates on 28 VDC sup-
plied through the 2-amp
TRIM-FLAP-SPOILER INDICATOR circuit
breaker on the copilot's circuit breaker panel . The
flap position indica-
tor is operative
during the EMER BUS mode .
SPOILERS
The spoilers, located on the upper surface of the wings forward
of
the
flaps,' may be extended
symmetrically for use as spoilers or asymmetri-
cally for aileron augmentation when the flaps
are extended . The spoil-
ers are electrically controlled and hydraulically actuated either
by a
control switch
(Normal Spoiler Mode), by the wing flap position
switches (Spoileron), or
automatically during ground operations when
the thrust levers are pulled to idle
(Autospoilers) .
Autospoilers
: On aircraft 60-001 thru 60-078 & 60-080 thru 60-093 not
modified by SB 60-27-6
(Autospoiler Wheel Speed Detection System), the
autospoiler mode is used
to automatically extend the spoilers on land-
ing or in the 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 both squat switch circuits
indicate
an
"on
ground" condition and both thrust levers are in the
IDLE position . The squat
switch circuits are electronically latched in the
"on ground" state once the initial
weight-on-wheels signal is received .
This
prevents inadvertent spoiler retraction in
the
event
the aircraft
should
bounce during the ground roll . If either thrust lever is moved
above IDLE while autospoilers
are extended, the spoilers will immedi-
ately retract . Flap position has no effect
on autospoiler operation and
autospoilers are not operational when EXT or RET is selected .
Auto-
spoiler control circuits
operate on 28 VDC supplied through the 3-amp
SPOILER circuit breaker on the
copilot's circuit breaker panel . Auto-
spoilers are operative during the EMER BUS
mode .
5-4
PM-123
Change 4