bleed-air panel. Pressure will be approxi-
mately 50 psi. APU bleed air can be supplied
to the right side of the bleed-air manifold by
pushing the ISOL switchlight. The green
OPEN light will illuminate and the right pres-
sure indicator will also read approximately
50 psi.
NOTE
The left and right engine bleed-air
switches must remain off. Selecting
the left switch or selecting the right
switch and isolation valve switch will
automatically close the APU LCV.
Air from the bleed-air manifold to the ACU’s
is controlled by the left and right ACU switch-
lights (Figure 11-2). The OFF lights will ex-
tinguish to indicate switch selection, and the
FAIL lights will illuminate only when there is
a malfunction. The system is now in operation
for ground heating or cooling, depending on
the temperature selection.
Figure 11-5 shows the air-conditioning airflow
schematic. Refer to this figure while studying
the system operation.
GROUND OPERATION
Initially, the APU supplies the 10th-stage
bleed-air manifold. The isolation valve is se-
lected open and air from the manifold is di-
r e c t e d t h r o u g h t h e l e f t a n d r i g h t AC U
pressure-regulating and shutoff valves. The
ACU valves are operating in the high mode.
From here on, the operation of the right ACU
will be described. Operation of the left ACU
is identical. From the ACU valve, the hot bleed
air passes through a bleed-air filter, used to ex-
tract contaminants, and then through the pre-
cooler. The WOW system has opened the
ejector valve, inducing ambient air from the
ram-air intake through the precooler and heat
exchangers. From the precooler, the flow will
be through the primary heat exchanger and
then to the ACU compressor where a pressure
and temperature increase occurs. Outflow
from the ACU compressor is directed through
the secondary heat exchanger where temper-
ature is reduced but pressure is not. This air-
flow is then directed through a water extractor
to the expansion turbine where expansion and
cooling occurs. The air passes through the
water separator and on to the temperature con-
trol system. Here, mixing of hot air and cold
air results in conditioned air at a selected tem-
perature. This conditioned air is directed to the
cabin conditioned air outlets. The crossover,
or balance, ducts allow this air to also enter
the cockpit conditioned air ducts. In addi-
tion, the cooled airflow from the water sepa-
rator goes directly to the cabin cold air outlets
(gaspers), the cockpit cold air outlets, and the
instrument panel cooling duct.
NOTE
Unless aircraft fitted with SB601-
0450, both ACU switchlights must be
selected OFF prior to starting the
engine.
IN-FLIGHT OPERATION
When the engines are operating, the pilot may
select the APU bleed air off, close the isola-
tion valve, and open the left and right engine
bleed-air valves and ACU valves. This will be
the normal method of in-flight operation.
Operation of the system will be similar to that
explained above except that now the engines
are supplying the airflow, and the pressure-reg-
ulating and shutoff valves will operate in the
low mode. If one ACU is selected off, the
other will operate in high mode.
FlightSafety Canada
L t é e
L t d .
CL-600-2B16 PILOT TRAINING MANUAL
11-6
CL 601-3R
FOR TRAINING PURPOSES ONLY