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STANDBY INSTRUMENTS
The standby instrument group includes a
Mach/airspeed indicator, an attitude indicator,
and a barometric altimeter. These three in-
struments are mounted on the center instrument
panel above the CWP and RMUs (Figure 16-
23). Additionally, a magnetic compass is
mounted on the windshield splitter. These
backup flight instruments are provided in the
event of multiple failures of the EFIS, ADCs,
AHRS, pitot-static system, or electrical sys-
tem failure (dual generator failure).
The standby magnetic compass, altimeter and
airspeed indicator do not require electrical
power for operation but are lighted with power
from the emergency battery bus. The standard
standby altimeter contains a vibrator motor for
improved performance. The vibrator motor is
powered from the emergency battery bus and
a red "OFF" flag appears on the face of the
standby altimeter, beneath VIB, whenever
power is lost.
The standby attitude indicator and it's inter-
nal lighting are also powered by the emer-
g e n c y b a t t e r y b u s . I n t h e ev e n t o f d u a l
generator failure, the standard emergency bat-
tery will power the standby attitude indicator
for at least 1 hour. The rotor speed of the gyro
provides a minimum of 9 minutes of useful at-
titude information after a complete loss of
power to the indicator. Whenever power is in-
terrupted to the gyro, a red flag will appear on
the indicator. The flag will also be in view
when the PULL TO CAGE knob is in the caged
position.
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
16-32
FOR TRAINING PURPOSES ONLY
FlightSafety
international
Figure 16-23. Standby Instrument Group