TM 1-1520-238-T-5
7–33
7–7.
SYSTEM DESCRIPTION (cont)
7–
PRESSURE
RETURN
M68-113A
DIRECTIONAL
SERVOCYLINDER
LOW LEVEL
SWITCH
UTILITY
MANIFOLD
PROXIMITY
SWITCH
TAIL WHEEL LOCK
ACTUATOR
CHECK
VALVE
EMERGENCY
HYDRAULIC
SHUTOFF
VALVE
TAIL WHEEL LOCK
CONTROL VALVE
PRESSURE
RETURN
LEGEND
Figure 7–16.
Tail Wheel Lock and Emergency Hydraulic Shutoff Valves
d. PAS.
The PAS system provides air for use by air driven or operated components such as the air turbine
starters, environmental control system (ECS), canopy side window defogging, engine cooling louver actuators,
hydraulic reservoir pressurization, ice detector sensor, the nitrogen inerting system, and regulated air pressure to
the fuel system components.
(1) Purpose (fig. 7–17).
The PAS cleans, pressurizes, regulates, and distributes air to the following
pneumatically operated systems and components: main engine starting, ECS, canopy/windshield defog, louver
actuators, ice detector probe, hydraulic system, utility receptacle, nitrogen inerting system, and the air pressure
regulating valve (to fuel system).
