TM 1-1520-238-T-5
Change 4
7–131
7–45.
PRESSURIZED AIR SYSTEM – MAINTENANCE OPERATIONAL CHECK (cont)
7–45
M68-034
FUEL BST
LT PRI
Figure 7–53.
Pilot Center Circuit Breaker Panel
SHAFT DRIVEN
COMP INDICATOR
M68-035
Figure 7–54.
Pilot Caution/Warning Panel
WARNING
APU is operating. To prevent injury to personnel, avoid contact with
rotating components and high pressure air discharge. Secure any loose
clothing and personal articles. Failure to do so could result in death or
serious injury. If injury occurs, get medical aid immediately.
Task
Result
b. Set ENCU temperature switch (fig. 7–52) to
full WARM. On aft deck, check for pulsing
air discharge from PAS overboard vent
(fig. 7–55).
If a pulsing air discharge is present or a loud banging
sound (surge) is heard, immediately shut down APU
(TM 1-1520-238-CL) and replace SDC
(TM 1-1520-238-23).
c. Check that air flows from ECS vents.
If air does not flow from ECS vents, have assistant
check ENCU shutoff valve indicator on aft deck
(fig. 7–51). If valve indicates OPEN, replace SDC
(TM 1-1520-238-23). If valve indicates CLOSED,
refer to TM 1-1520-238-T-8 to troubleshoot ECS.
