Brake System Indications
Brake accumulator hydraulic pressure is nor-
mally displayed on the EICAS SUMRY page
(Figure 14-20). It can also be displayed on
the EICAS/MFD hydraulic system schematic
display (Figure 14-22). Operating under de-
graded display options or reversion proce-
d u r e s , t h e b r a ke a c c u m u l a t o r h y d r a u l i c
pressure is also displayed on the RMU backup
engine/system page (Figure 14-21).
On the SUMRY display, brake accumulator
pressure is annotated “B-ACUM.” On the sys-
tem schematic displays available on the EICAS
and MFD (Figure 14-22), brake accumulator
pressure is annunciated in the top right corner
of the schematic and has both a digital read-
out and an analog tape display of brake pres-
s u r e . O n t h e R M U e n g i n e p a g e s , b r a k e
accumulator pressure is annunciated on page
1, to the right of the caption “HYDM-B.”
Main Hydraulic System Failure
In the event of a failure of the main hydraulic
system, the brake source shuttle valve auto-
matically changes the source of hydraulic fluid
flow from the main system to the auxiliary
hydraulic system if the auxiliary hydraulic
system is turned on. With the auxiliary hy-
draulic pump operating, normal braking with
anti-skid protection is available. If the hy-
draulic crossflow valve is open and the fluid
level in the auxiliary hydraulic fluid reser-
voir is low, the hydraulic crossflow valve is au-
tomatically closed, conserving the remaining
hydraulic fluid for the wheel brakes. An amber
CAS message “AUX HYD QTY LO” will also
be displayed in this case.
14-20
FOR TRAINING PURPOSES ONLY
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
FlightSafety
international
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
FlightSafety
international
Honeywell
TUNE
SQ
DIM
1/2
STO
DME
TST
PGE
ID
FUEL
HYD
M-B
SPL
FLP
MORE
10
3000
1400
20
3000
1450
ITT
O/P
76
550
80
550
N1
IGN
75.0
IGN
75.0
Figure 14-21. Brake Accumulator
Hydraulic Pressure Display on RMU
FUEL
FLT
ECS
HYD
R
1750
FLAPS
PITCH TRIM
LBS
0
8.0
8.0
00
50
HYD/ECS
MAIN
B-ACUM
CAB ALT
OXY QTY
3000
3000
1300
669
SPLR
PIT
AIL
RUD
Figure 14-20. Brake Accumulator
Hydraulic Pressure Display on EICAS/MFD
SUMRY Display