TM 55-1510-215-10
2-58. Windshield Electrothermal Anti-Ice Systems.
fuel management panel. Each oxygen supply valve has
a flow governing feature controlled by an integral
a. Description. Both pilot and copilot windshields
pressure differential sensor. When initially turned ON by
are provided with an independent electrothermal anti-ice
the pilot, only a small flow is allowed to meter into the
system. Each system is comprised of the windshield
line. Flow restriction continues until the pressure levels
assembly with heating wires sandwiched between glass
are equalized at which time the valve opens up
panels, a temperature sensor attached to the glass, an
completely, permitting a full flow condition. The forward
electrothermal controller, a relay switch, and a control
valve (fig.
switch.
Both ON-OFF control switches, placarded
controls high pressure flow to a pressure reducer located
WINDSHIELD ANTI-ICE -PILOT, COPILOT, are located
on the forward cabin wall behind the instrument panel.
on the left subpanel (fig. 2-7). Each switch controls one
This reducer lowers pressure to a 300 to 400 PSI range
electrothermal windshield system. The circuits of each
and routes oxygen to the regulator control panels for the
system are protected by a respective 1/2-ampere circuit
pilot and copilot. The pilot's and copilot's regulators are
breaker and a respective 25-ampere circuit breaker on
of the diluter demand type.
That is, when in the
the right subpanel, placarded WINDSHIELD ANTI-ICE -
NORMAL OXYGEN mode the regulator mixes the
PILOT, COPILOT (fig. 2-7).
proper amount of oxygen for a given amount of air at
flight altitude. The aft slow-release valve, placarded
b. Normal Operation.
Each elecrothermal
CABIN OXYGEN, controls supply to the cabin oxygen
windshield is activated by placing the corresponding
regulators, which provides passenger-regulated 100%
WINDSHIELD ANTI-ICE switch to the ON position. If
oxygen to the passenger oxygen outlets. A plug-in type
glass temperature is below 43 C, the electrothermal
valve at each of six stations above the seat positions
delivers oxygen for passenger use. The 100% oxygen
controller will actuate a relay switch applying power to
flows continuously to passengers, when the masks are
the heating wires sandwiched within the glass. A
coupled into an oxygen outlet.
windshield will warm to a maximum of 43C and then will
cycle off. It will recycle ON again when the glass
(1) Regulator control panels.
The pilot's
temperature drops 2.5C below cutoff. Refer to chapter
oxygen regulator control panel is located on the cockpit
sidewall below the fuel management panel.
The
copilot's oxygen regulator control panel is located on the
2-59. Oxygen System.
cockpit sidewall below the copilot's circuit breaker panel.
The cabin regulator panels are located on each side of
a. Description. The pilot, copilot, and passengers
the cabin sidewall (fig. 2-17). Each panel contains a
will receive oxygen from a supply system which has a
blinker-type flow indicator, a 2000 PSI gage, a red
capacity which ranges from 11 cu ft to 214 cu ft,
emergency
pressure
control
lever
placarded:
depending upon the combination of supply cylinders
EMERGENCY-NORMAL-TEST MASK, a white diluter
which are coupled into provisions of the aircraft. Figure
control lever placarded 100% OXYGEN and NORMAL,
OXYGEN, and a green supply control lever placarded
are in the left nose compartment below the avionics
ON/OFF. The supply control lever turns the individual
equipment, and some may be located aft of the main
regulator ON and OFF. The diluter control lever gives
entrance door in the cabin.
All cylinders are
the selection of either normal or 100% oxygen but acts
interconnected, using check valves, so that refilling of all
to select only when the emergency pressure control
cylinders can be accomplished through a single filler
lever is placed in NORMAL position.
valve located in the cabin adjacent to the 11-cu ft
cylinder. Each cylinder has a pressure gage. The
oxygen system pressure gage, placarded OXYGEN
CAUTION
SUPPLY PRESSURE, is located aft of the fuel
management panel. This gage shows the amount of
pressure remaining in the oxygen supply cylinders.
When not in use, the diluter control
system for all crew and passenger combinations.
lever should be left in the 100%
Supply lines from the cylinders are routed to two high
OXYGEN
position
to
prevent
pressure, slow-release supply valves located below the
regulator contamination.
2-40
