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tion of the EICAS (Engine Instrument/Crew
Alerting System) normally on display unit 2
(DU 2). Using display unit reversion, the CAS
messages and EICAS display can be trans-
ferred to DU 3.
Although airplane system malfunction alert-
ing is described within each airplane system
chapter, the entire master list of CAS mes-
sages is covered within this chapter to provide
a single-source reference. Table 4-2 lists all
possible CAS messages categorized by air-
plane system.
MASTER
WARNING/CAUTION
LIGHTS
The master WARN/CAUT lights are switch/in-
dicators (S/Is) with “WARN” in red letters in
the upper half of the switch and “CAUT” in
amber letters in the lower half (Figure 4-1).
Each master WARN/CAUT light has four bulbs
for redundancy. When the master warning or
master caution system is triggered, the ap-
propriate section (WARN or CAUT) of the
S/Is will flash to alert the crew to the condi-
tion. A master warning aural tone (triple
chime) sounds with activation of the master
WARN lights and a master caution aural tone
(single chime) sounds with activation of the
master CAUT lights. Depressing either mas-
ter WARN/CAUT light extinguishes the flash-
ing WARN or CAUT lights.
When a red CWP light, a red APU (if installed)
“FIRE PUSH” or a red engine “FIRE PUSH”
light illuminates, the red WARN portion of
both master WARN/CAUT lights flash and
the triple chime master warning tone sounds.
When the master warning is activated, the
master warning tone (3 chimes) will repeat
until acknowledged. If the master warning is
followed by a voice message, only the voice
message will repeat until cancelled. Except for
an engine fire indication, there will be an ac-
companying, flashing red, CAS message to
announce the condition; and in some cases,
there will be an accompanying voice message
(See Table 4-1).
D e p r e s s i n g e i t h e r f l a s h i n g m a s t e r
WARN/CAUT light causes both master WARN
lights to extinguish and the red CAS message
to stop flashing. Also, if the accompanying
voice message is mutable, it will be cancelled
when either master WARN/CAUT light is de-
pressed. The applicable CAS message and
CWP, APU fire, or engine fire light remains
illuminated until the malfunction is cleared.
If the fault clears prior to depressing either
master WARN/CAUT light to cancel it, the
master WARN/CAUT lights extinguish.
When a flashing amber CAS message is an-
nunciated, the amber CAUT portion of both
master WARN/CAUT lights flash and the sin-
g l e c h i m e m a s t e r c a u t i o n t o n e s o u n d s .
Depressing either master WARN/CAUT light
causes the master CAUT lights to extinguish
and the amber CAS message to stop flashing.
The amber CAS message remains on the dis-
play until the malfunction is cleared.
To eliminate nuisance master caution lights and
tones while the airplane is on the ground, es-
pecially during preflight checks, the master
C AU T l i g h t a n d t o n e c a n b e i n h i b i t e d .
D e p r e s s i n g a n d h o l d i n g e i t h e r m a s t e r
WARN/CAUT light for more than 2 seconds
activates the inhibit mode. While holding ei-
ther master WARN/CAUT light depressed,
the master CAUT light will blink on-and-off
once to indicate the inhibit mode has been ac-
tivated.
The master caution inhibit mode does not pre-
vent amber CAS messages from appearing,
but does inhibit the normally accompanying
master caution tone and flashing master CAUT
lights. Also, the master caution inhibit does
not affect operation of the master WARN
lights.The master CAUT light can only be in-
hibited by the crew on the ground and inhibit
is deactivated automatically by any of the fol-
lowing actions:
• Initiating START on either engine.
L E A R J E T 4 5
P I L O T T R A I N I N G M A N U A L
4-2
FOR TRAINING PURPOSES ONLY
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