Learjet 60 - Page 37

Learjet 6U

Pilot's Manual
ENG
CMPTR LIGHTS
Two ENG CMPTR lights are provided for each engine and reside in the
i a t or
panel .
Coe blot is white
and one is
amber . Illumination
of
a
white light indicates
a minor
malfunction in one or both
channels of
fated FADEC . Illumination
of an
amber
light
indicates a major
malfunction in one channel of the associated FADEC . Illumination of
both
the
white
and amber lights indicates a malfunction in both chan-
nels of the associated
FADEC . Dispatch is not permitted with any white
or amber light i I tuminated .
VARIABLE
INLET GUIDE
VANES AND VARIABLE $TAT
The engine is equipped with variable inlet guide vanes to direct air into
the first stage axial compressor
and variable
stator vanes
13
direct
a
into
the second cage
axial compressor
.
This feature permits peak com-
pressor efficiency throughout various
operating
conditions
. A variable
guide vane actuator is used to simultaneously position the guide vanes
and stator vanes .
The
FADEC computes the desired vane position and
commands the HFCU
to
provide servo pressures (fuel) to the actuator
which positions the vanes
. A rotary variable differential transformer
(RVDT) position
transducer, mounted
on the actuator, sends an electri-
cal feedback signal to the FADEC .
SURGE
BLEED
CONTRO
Each engine has a surge bleed control system which allows
surge free
operation throughout various
operating
conditions and improves en-
gine
starting
characteristics . The system consists of a solenoid control
valve and three bleed-off
valves
(103VI Two valves
bleed
compressor
air from station 2 .5 while the third valve bleeds air from station 2 .8 .
osition is controlled by the FADEC via the solenoid control
valve . Compressor
discharge
air (P3) is used to provide servo pre
to close the bleed-off valveMTFhe solenoid control valve applies P3 pres-
sure to be BOVs to close them and vents P3 pressure to open them . In
the event a solenoid control valve fails, the bleed-off valves will go to
open posithiomn
.
VANES