Learjet 60 - Landing Gear Warning System

Pilot's
Manual

Learjet 60
LANDING
GEAR WARNING SYSTEM
A
landing gear
warning system is
installed to warn the operator
of
potentially
unsafe flight conditions
with the landing gear
retracted .
The system consists
of the landing
gear warning horn, a thrust
lever
position switch,
and flap position
switches . The warning system also
uses
the landing
gear position switches
and UNSAFE lights .
The
ADCs (air data
computers) provide
the airspeed /altitude trip
signal .
Depending upon
the flight
condition encountered, one of
two distinct
warnings
will be given as
follows :
Warning horn
sounds and UNSAFE
lights illuminate - This
indi-
cates that the
landing gear is not locked
down, airspeed is below ap-
proximately 170
KIAS, altitude is below
approximately 16,300
feet,
and at least
one thrust lever is below
the 60% Nl position . When
the
horn sounds
under these conditions,
the horn can be silenced by de-
pressing the MUTE
switch on the LANDING
GEAR control panel or
depressing the MUTE
button in the right thrust
lever handle . When-
ever the warning horn
has been muted, the amber
MUTE light on the
LANDING GEAR control
panel will illuminate .
The UNSAFE light
indication will continue
until either the landing
gear is extended, air-
speed is increased
above 190 KIAS or one of
the above conditions is
corrected .
Warning horn sounds - Normally,
sounding of the warning horn
without a corresponding UNSAFE light indication
signifies that the
landing gear is
not locked down and the flaps are lowered beyond
25° . When the horn sounds
because the flaps are lowered, the horn
cannot be silenced by either
mute switch . The horn will continue to
sound until either the landing
gear is extended or the flaps are
retracted .
3- 1 0
PM-123
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