359
Federal Aviation Administration, DOT
§ 25.1439
(5) Be designed to use any suitable
hydraulic fluid specified by the air-
plane manufacturer, which must be
identified by appropriate markings as
required by § 25.1541.
(c)
Tests. Tests must be conducted on
the hydraulic system(s), and/or sub-
system(s) and elements, except that
analysis may be used in place of or to
supplement testing, where the analysis
is shown to be reliable and appropriate.
All internal and external influences
must be taken into account to an ex-
tent necessary to evaluate their ef-
fects, and to assure reliable system and
element functioning and integration.
Failure or unacceptable deficiency of
an element or system must be cor-
rected and be sufficiently retested,
where necessary.
(1) The system(s), subsystem(s), or
element(s) must be subjected to per-
formance, fatigue, and endurance tests
representative of airplane ground and
flight operations.
(2) The complete system must be
tested to determine proper functional
performance and relation to the other
systems, including simulation of rel-
evant failure conditions, and to sup-
port or validate element design.
(3) The complete hydraulic system(s)
must be functionally tested on the air-
plane in normal operation over the
range of motion of all associated user
systems. The test must be conducted at
the system relief pressure or 1.25 times
the DOP if a system pressure relief de-
vice is not part of the system design.
Clearances between hydraulic system
elements and other systems or struc-
tural elements must remain adequate
and there must be no detrimental ef-
fects.
[Doc. No. 28617, 66 FR 27402, May 16, 2001]
§ 25.1438
Pressurization and pneu-
matic systems.
(a) Pressurization system elements
must be burst pressure tested to 2.0
times, and proof pressure tested to 1.5
times, the maximum normal operating
pressure.
(b) Pneumatic system elements must
be burst pressure tested to 3.0 times,
and proof pressure tested to 1.5 times,
the maximum normal operating pres-
sure.
(c) An analysis, or a combination of
analysis and test, may be substituted
for any test required by paragraph (a)
or (b) of this section if the Adminis-
trator finds it equivalent to the re-
quired test.
[Amdt. 25–41, 42 FR 36971, July 18, 1977]
§ 25.1439
Protective breathing equip-
ment.
(a) Fixed (stationary, or built in) pro-
tective breathing equipment must be
installed for the use of the flightcrew,
and at least one portable protective
breathing equipment shall be located
at or near the flight deck for use by a
flight crewmember. In addition, port-
able protective breathing equipment
must be installed for the use of appro-
priate crewmembers for fighting fires
in compartments accessible in flight
other than the flight deck. This in-
cludes isolated compartments and
upper and lower lobe galleys, in which
crewmember occupancy is permitted
during flight. Equipment must be in-
stalled for the maximum number of
crewmembers expected to be in the
area during any operation.
(b) For protective breathing equip-
ment required by paragraph (a) of this
section or by the applicable Operating
Regulations:
(1) The equipment must be designed
to protect the appropriate crewmember
from smoke, carbon dioxide, and other
harmful gases while on flight deck
duty or while combating fires.
(2) The equipment must include—
(i) Masks covering the eyes, nose and
mouth, or
(ii) Masks covering the nose and
mouth, plus accessory equipment to
cover the eyes.
(3) Equipment, including portable
equipment, must allow communication
with other crewmembers while in use.
Equipment available at flightcrew as-
signed duty stations must also enable
the flightcrew to use radio equipment.
(4) The part of the equipment pro-
tecting the eyes shall not cause any ap-
preciable adverse effect on vision and
must allow corrective glasses to be
worn.
(5) The equipment must supply pro-
tective oxygen of 15 minutes duration
per crewmember at a pressure altitude
of 8,000 feet with a respiratory minute
VerDate Sep<11>2014
09:06 Jun 28, 2024
Jkt 262046
PO 00000
Frm 00369
Fmt 8010
Sfmt 8010
Y:\SGML\262046.XXX
262046
jspears on DSK121TN23PROD with CFR
360
14 CFR Ch. I (1–1–24 Edition)
§ 25.1441
volume of 30 liters per minute BTPD.
The equipment and system must be de-
signed to prevent any inward leakage
to the inside of the device and prevent
any outward leakage causing signifi-
cant increase in the oxygen content of
the local ambient atmosphere. If a de-
mand oxygen system is used, a supply
of 300 liters of free oxygen at 70
°
F. and
760 mm. Hg. pressure is considered to
be of 15-minute duration at the pre-
scribed altitude and minute volume. If
a continuous flow open circuit protec-
tive breathing system is used, a flow
rate of 60 liters per minute at 8,000 feet
(45 liters per minute at sea level) and a
supply of 600 liters of free oxygen at 70
°
F. and 760 mm. Hg. pressure is consid-
ered to be of 15-minute duration at the
prescribed altitude and minute volume.
Continuous flow systems must not in-
crease the ambient oxygen content of
the local atmosphere above that of de-
mand systems. BTPD refers to body
temperature conditions (that is, 37
°
C.,
at ambient pressure, dry).
(6) The equipment must meet the re-
quirements of § 25.1441.
[Doc. No. FAA–2002–13859, 69 FR 40528, July 2,
2004]
§ 25.1441
Oxygen equipment and sup-
ply.
(a) If certification with supplemental
oxygen equipment is requested, the
equipment must meet the requirements
of this section and §§ 25.1443 through
25.1453.
(b) The oxygen system must be free
from hazards in itself, in its method of
operation, and in its effect upon other
components.
(c) There must be a means to allow
the crew to readily determine, during
flight, the quantity of oxygen available
in each source of supply.
(d) The oxygen flow rate and the oxy-
gen equipment for airplanes for which
certification for operation above 40,000
feet is requested must be approved.
§ 25.1443
Minimum mass flow of sup-
plemental oxygen.
(a) If continuous flow equipment is
installed for use by flight crew-
members, the minimum mass flow of
supplemental oxygen required for each
crewmember may not be less than the
flow required to maintain, during in-
spiration, a mean tracheal oxygen par-
tial pressure of 149 mm. Hg. when
breathing 15 liters per minute, BTPS,
and with a maximum tidal volume of
700 cc. with a constant time interval
between respirations.
(b) If demand equipment is installed
for use by flight crewmembers, the
minimum mass flow of supplemental
oxygen required for each crewmember
may not be less than the flow required
to maintain, during inspiration, a
mean tracheal oxygen partial pressure
of 122 mm. Hg., up to and including 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
minute BTPS. In addition, there must
be means to allow the crew to use undi-
luted oxygen at their discretion.
(c) For passengers and cabin attend-
ants, the minimum mass flow of sup-
plemental oxygen required for each
person at various cabin pressure alti-
tudes may not be less than the flow re-
quired to maintain, during inspiration
and while using the oxygen equipment
(including masks) provided, the fol-
lowing mean tracheal oxygen partial
pressures:
(1) At cabin pressure altitudes above
10,000 feet up to and including 18,500
feet, a mean tracheal oxygen partial
pressure of 100 mm. Hg. when breathing
15 liters per minute, BTPS, and with a
tidal volume of 700 cc. with a constant
time interval between respirations.
(2) At cabin pressure altitudes above
18,500 feet up to and including 40,000
feet, a mean tracheal oxygen partial
pressure of 83.8 mm. Hg. when breath-
ing 30 liters per minute, BTPS, and
with a tidal volume of 1,100 cc. with a
constant time interval between res-
pirations.
(d) If first-aid oxygen equipment is
installed, the minimum mass flow of
oxygen to each user may not be less
than four liters per minute, STPD.
However, there may be a means to de-
crease this flow to not less than two li-
ters per minute, STPD, at any cabin al-
titude. The quantity of oxygen re-
quired is based upon an average flow
rate of three liters per minute per per-
son for whom first-aid oxygen is re-
quired.
VerDate Sep<11>2014
09:06 Jun 28, 2024
Jkt 262046
PO 00000
Frm 00370
Fmt 8010
Sfmt 8010
Y:\SGML\262046.XXX
262046
jspears on DSK121TN23PROD with CFR