Learjet 60 - Page 54

Pilot's
Manual

Learjet 60
TR DEPLOY
light and a discrete
signal
is
sent to the on-side FADEC to
allow
engine thrust to increase above idle .
The Ni bug will reposition
indicating the
FADEC is utilizing the reverse
thrust schedule . A throt-
tle balk solenoid
prevents either thrust
reverser lever from moving
sig-
nificantly above
reverse idle until both
thrust reversers are fully de-
ployed .
Once the deploy switches
on both thrust reversers
are
actuated,
the solenoid is
energized allowing the thrust reverser
levers
to move
into the reverse thrust
range .
STOW
To stow
the thrust reverser,
the thrust reverser lever is moved
into the
STOW
position . The thrust
reverser relay box will signal the
applica-
ble HCU to
apply hydraulic
pressure to the stow port of the
thrust re-
verser
actuators (inboard
and outboard) . Once the
thrust reverser
doors move out of the
deployed position, the deploy
switch sends a
signal to extinguish
the white TR DEPLOY
light, illuminate the amber
TR UNLOCK light
and a discrete signal is sent
to the on-side FADEC
to limit engine thrust
to idle . When the doors
reach the stowed posi-
tion, the primary
latch stow switches send
a discrete signal to the
on-
side FADEC to
restore engine thrust . The
upper and lower doors
trip
their respective spring-loaded
secondary latches as they reach
the
stowed and locked position . At
this point, the secondary latch stow
switches send a signal to extinguish the
TR UNLOCK light .
AUTO STOW
The thrust reverser doors are
mechanically secured in the stowed
po-
sition
by a four-bar overcenter door
linkage (primary latch) . Should
an
uncommanded unlock condition be
sensed by the primary
latch
stow
switches, an auto stow sequence
will be initiated . The thrust
re-
verser
relay box will command the HCU
to open the isolation
valve
and apply hydraulic
pressure to the stow port of the thrust
reverser
actuators (inboard and
outboard) . A primary latch unlock condition
will result in a discrete signal
being sent to the on-side FADEC to lim-
it thrust to flight idle, regardless of throttle position,
until the thrust
reverser is returned to the stowed position . An unlock
condition
sensed by the secondary latch stow switches
will
illuminate
the TR
UNLOCK light but will not initiate the auto stow sequence .
2-22
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PM-123
Change 3