317
Federal Aviation Administration, DOT
§ 23.1447
(c) If demand equipment is installed
for use by flight crewmembers, the
minimum mass flow of supplemental
oxygen required for each flight crew-
member may not be less than the flow
required to maintain, during inspira-
tion, a mean tracheal oxygen partial
pressure of 122mm Hg up to and includ-
ing a cabin pressure altitude of 35,000
feet, and 95 percent oxygen between
cabin pressure altitudes of 35,000 and
40,000 feet, when breathing 20 liters per
minutes BTPS. In addition, there must
be means to allow the flight crew to
use undiluted oxygen at their discre-
tion.
(d) If first-aid oxygen equipment is
installed, the minimum mass flow of
oxygen to each user may not be less
than 4 liters per minute, STPD. How-
ever, there may be a means to decrease
this flow to not less than 2 liters per
minute, STPD, at any cabin altitude.
The quantity of oxygen required is
based upon an average flow rate of 3 li-
ters per minute per person for whom
first-aid oxygen is required.
(e) As used in this section:
(1) BTPS means Body Temperature,
and Pressure, Saturated (which is 37
°
C,
and the ambient pressure to which the
body is exposed, minus 47mm Hg, which
is the tracheal pressure displaced by
water vapor pressure when the
breathed air becomes saturated with
water vapor at 37
°
C).
(2) STPD means Standard, Tempera-
ture, and Pressure, Dry (which is 0
°
C
at 760mm Hg with no water vapor).
[Doc. No. FAA–2009–0738, 76 FR 75761, Dec. 2,
2011]
§ 23.1445
Oxygen distribution system.
(a) Except for flexible lines from oxy-
gen outlets to the dispensing units, or
where shown to be otherwise suitable
to the installation, nonmetallic tubing
must not be used for any oxygen line
that is normally pressurized during
flight.
(b) Nonmetallic oxygen distribution
lines must not be routed where they
may be subjected to elevated tempera-
tures, electrical arcing, and released
flammable fluids that might result
from any probable failure.
(c) If the flight crew and passengers
share a common source of oxygen, a
means to separately reserve the min-
imum supply required by the flight
crew must be provided.
[Doc. No. 26344, 58 FR 18978, Apr. 9, 1993, as
amended by Amdt. 23–62, 76 FR 75762, Dec. 2,
2011]
§ 23.1447
Equipment standards for ox-
ygen dispensing units.
If oxygen dispensing units are in-
stalled, the following apply:
(a) There must be an individual dis-
pensing unit for each occupant for
whom supplemental oxygen is to be
supplied. Each dispensing unit must:
(1) Provide for effective utilization of
the oxygen being delivered to the unit.
(2) Be capable of being readily placed
into position on the face of the user.
(3) Be equipped with a suitable means
to retain the unit in position on the
face.
(4) If radio equipment is installed,
the flightcrew oxygen dispensing units
must be designed to allow the use of
that equipment and to allow commu-
nication with any other required crew
member while at their assigned duty
station.
(b) If certification for operation up to
and including 18,000 feet (MSL) is re-
quested, each oxygen dispensing unit
must:
(1) Cover the nose and mouth of the
user; or
(2) Be a nasal cannula, in which case
one oxygen dispensing unit covering
both the nose and mouth of the user
must be available. In addition, each
nasal cannula or its connecting tubing
must have permanently affixed—
(i) A visible warning against smoking
while in use;
(ii) An illustration of the correct
method of donning; and
(iii) A visible warning against use
with nasal obstructions or head colds
with resultant nasal congestion.
(c) If certification for operation
above 18,000 feet (MSL) is requested,
each oxygen dispensing unit must
cover the nose and mouth of the user.
(d) For a pressurized airplane de-
signed to operate at flight altitudes
above 25,000 feet (MSL), the dispensing
units must meet the following:
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