TM 1-1510-224-10
position of the emergency pressure control lever (red) on
his regulator control panel. This selection provides
100% oxygen at a positive pressure, regardless of the
position of the diluter control lever.
f.
First Aid Operation. A first aid oxygen mask is
installed in the aft cabin area as a supplemental or
emergency source of oxygen. The mask is stowed
behind an overhead cover, placarded
FIRST AID
OXYGEN - PULL. Removing the cover allows the mask
to drop out of the container, exposing a manual control
valve, which releases oxygen to the mask when placed
in the ON position. After using the mask, the manual
valve in the, container must be turned OFF before
stowing the mask and replacing the cover.
g.
Oxygen Duration Examples.
(1)
Example one.
(a)
Wanted. Duration in minutes of
oxygen at 100% capacity.
(b)
Known. Two man crew plus one
passenger, cabin pressure altitude = 15,000 feet, crew
masks, normal, 100% capacity.
(c)
Method. Find "two man crew plus
one pass # line (table 2-5), move right then down to
15,000 "normal", read 232.1 minutes.
(2)
Example two.
(a)
Wanted. Duration of oxygen for
previous example data at 84% of capacity.
(b)
Known. 232.1 minutes duration at
100%, 84% capacity, total aircraft flow = 13.9 LPM.
(c)
Method. Multiply 232.1 X 0.84 =
194.9 minutes, or multiply 3,226 X 0.84 = 2709.8, divide
by 13.9 LPM = 194.9 minutes.
(3)
Example three.
(a)
Wanted. Duration of oxygen for
complement at other cabin pressure altitude, at less than
100% capacity.
(b)
Known. Cylinder at 84% capacity,
100% capacity = 3,226 L, cabin pressure altitude =
21,000 feet.
1 crew mask = LPM (100%), 1 passenger mask = LPM
(c)
Method. Multiply 3,226 L X 0.84 =
2,709.8 L. Multiply 2 crew X 7.2 LPM = 14.4 LPM.
Multiply 1 passenger X 3.7 LPM, add 14.4 LPM crew
plus 3.7 LPM passenger = 18.1 LPM. Divide 2,709.8 L
by 18.1 LPM = 149.7 minutes.
h.
Oxygen Cylinder Capacity Example Problem.
Oxygen cylinder capacity is determined by using figure
2-27.
(1)
Example one.
(a)
Wanted. Percent of capacity at
known pressure and temperature and pressure when
temperature decreases.
(b)
Known. Pressure = 1,600 PSIG
stabilized cylinder temperature is estimated at 200C,
decreased stabilized cylinder temperature is estimated
at -30C.
(c)
Method. Enter 1600 PSIG, move up
to 200C line, move right to 84% then move left on 84%
line to -300C line, and move down to 1250 PSIG.
(2)
Example two.
Figure 2-27. Oxygen Cylinder Capacity
2-65
