TM 1-1510-225-CL
P-1
PERFORMANCE CHECKS
OXYGEN SYSTEM
1. Passenger manual drop-out – Push off.
2. Oxygen system – Crew ready.
3. Crew masks – 100%; check operation and stow.
NOTE
1850 psi at 15° is a fully charged bottle. Read
duration directly from P-1.
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.
NOTE
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).
(1) Pilot and copilot with masks set at 100%
plus 6 passengers = 10 people using
oxygen.
(2) Cylinder volume =115 cubic feet.
(3) Duration with full bottle = 73 minutes.
(4) Duration with 57% capacity: 0.57 x 73 =
41 minutes.
