1850 psi at 15° is a fully charged bottle. Read
duration directly from the Oxygen Duration
a. Read oxygen pressure from the gauge.
b. Read the OAT (with battery on).
c. Determine the percent of usable capacity from
Figure P-1 (e.g., 1100 psi at 0 °C = 57%).
d. Compute the oxygen duration in minutes from
Table P-1 by multiplying the full bottle
duration by the percent of usable capacity, as
in the following example.
(1) Pilot and copilot with masks set at 100%
plus 6 passengers = 10 people using
For oxygen duration computations, count
each diluter-demand crew mask in use as
two (e.g., with four passengers and a crew of
two, enter the table at eight people using).
(2) Cylinder volume = 115 cubic feet.
(3) Duration with full bottle = 73 minutes.
(4) Duration with 57% capacity: 0.57 x 73 =