PRESSURIZED AIR SYSTEM MAINTENANCE OPERATIONAL CHECK (cont)
PAS OVERBOARD VENTS
PAS Overboard Vents
d. On pilot ECS panel (fig. 752), set ENCU
switch to OFF. Check that air flow from the
ECS vents stops. After check is made, on
pilot ECS panel (fig. 752), set ENCU switch
If air flow continues from vents, have assistant check
ENCU shutoff valve indicator position (fig. 751) on
aft deck. If valve position indicates OPEN, refer to
TM 1-1520-238-T-8 to troubleshoot ECS system.
e. On pilot ANTI ICE panel (fig. 756), set
CANOPY DEFOG switch to ON. Check that
air flows from defog air mixers (fig. 757).
If air does not flow from defog air mixers, refer to
TM 1-1520-238-T-8 to troubleshoot antiice system.