Regulator control panels.
A valid cause for alarm would be the
rapid loss of oxygen pressure when
the aircraft is in level flight or
descending; should this condition
arise, descend as rapidly as possible
to an altitude which does not require
the use of oxygen.
Each regulator control panel contains a blinker-type flow
indicator, a 500 PSI pressure gage, a red emergency
NORMAL TEST MASK, a white diluter control lever
placarded 100% OXYGEN NORMAL OXYGEN, and a
green supply control lever placarded ON OFF. The
diluter control lever selects either normal or 100%
oxygen, but acts to select only when the emergency
pressure control lever is in the NORMAL position.
Table 2-5. Oxygen Duration In Minutes (140 Cubic Foot System)
When not in use, the diluter control
lever should be left in the 100%
OXYGEN position to prevent regulator
The emergency pressure control lever has
consumption for the individual using oxygen, and the
remaining position serves for testing hose and mask
integrity. In the EMERGENCY position, the control
lever causes 100% oxygen to be delivered at a safe,
positive pressure. In the NORMAL position, the lever
allows delivery of normal or 100% oxygen, depending
upon the selection of the diluter control lever. In TEST
MASK position, 100% oxygen at positive pressure is
delivered to check hose and mask integrity.
The 500 PSI oxygen pressure gage
provided on the oxygen control panels should never
indicate over 400 PSI. If the pressure exceeds 400 PSI,
a malfunction of the pressure reducer is indicated.
Whenever oxygen is inhaled, a blinker-vane slides into
view within the flow indicator window, showing that
oxygen is being released. When oxygen is exhaled, the
blinker vane vanishes from view.
Check to ensure that the OXYGEN
SUPPLY PRESSURE gage registers
adequate pressure before each flight.