spaschal on DSK3GDR082PROD with CFR

Federal Aviation Administration, DOT

Pt. 25, App. F

measured by a calibrated thermocouple pyrometer in the center of the flame must be
1550 SectionF. Suitable precautions must be taken
to avoid drafts. The flame must be applied
for 30 seconds with one-third contacting the
material at the center of the specimen and
then removed. Flame time, glow time, and
whether the flame penetrates (passes
through) the specimen must be recorded.
(7) Sixty degree test. A minimum of three
specimens of each wire specification (make
and size) must be tested. The specimen of
wire or cable (including insulation) must be
placed at an angle of 60Section with the horizontal
in the cabinet specified in subparagraph (3)
of this paragraph with the cabinet door open
during the test, or must be placed within a
chamber approximately 2 feet high by 1 foot
by 1 foot, open at the top and at one vertical
side (front), and which allows sufficient flow
of air for complete combustion, but which is
free from drafts. The specimen must be parallel to and approximately 6 inches from the
front of the chamber. The lower end of the
specimen must be held rigidly clamped. The
upper end of the specimen must pass over a
pulley or rod and must have an appropriate
weight attached to it so that the specimen is
held tautly throughout the flammability
test. The test specimen span between lower
clamp and upper pulley or rod must be 24
inches and must be marked 8 inches from the
lower end to indicate the central point for
flame application. A flame from a Bunsen or
Tirrill burner must be applied for 30 seconds
at the test mark. The burner must be mounted underneath the test mark on the specimen, perpendicular to the specimen and at
an angle of 30Section to the vertical plane of the
specimen. The burner must have a nominal
bore of 3-8-inch and be adjusted to provide a
3-inch high flame with an inner cone approximately one-third of the flame height.
The minimum temperature of the hottest
portion of the flame, as measured with a
calibrated thermocouple pyrometer, may not
be less than 1750 SectionF. The burner must be positioned so that the hottest portion of the
flame is applied to the test mark on the
wire. Flame time, burn length, and flaming
time of drippings, if any, must be recorded.
The burn length determined in accordance
with paragraph (8) of this paragraph must be
measured to the nearest tenth of an inch.
Breaking of the wire specimens is not considered a failure.
(8) Burn length. Burn length is the distance
from the original edge to the farthest evidence of damage to the test specimen due to
flame impingement, including areas of partial or complete consumption, charring, or
embrittlement, but not including areas sooted, stained, warped, or discolored, nor areas
where material has shrunk or melted away
from the heat source.

Part II - Flammability of Seat Cushions
(a) Criteria for Acceptance. Each seat cushion must meet the following criteria:
(1) At least three sets of seat bottom and
seat back cushion specimens must be tested.
(2) If the cushion is constructed with a fire
blocking material, the fire blocking material
must completely enclose the cushion foam
core material.
(3) Each specimen tested must be fabricated using the principal components (i.e.,
foam core, flotation material, fire blocking
material, if used, and dress covering) and assembly processes (representative seams and
closures) intended for use in the production
articles. If a different material combination
is used for the back cushion than for the bottom cushion, both material combinations
must be tested as complete specimen sets,
each set consisting of a back cushion specimen and a bottom cushion specimen. If a
cushion, including outer dress covering, is
demonstrated to meet the requirements of
this appendix using the oil burner test, the
dress covering of that cushion may be replaced with a similar dress covering provided
the burn length of the replacement covering,
as determined by the test specified in
Section 25.853(c), does not exceed the corresponding
burn length of the dress covering used on the
cushion subjected to the oil burner test.
(4) For at least two-thirds of the total
number of specimen sets tested, the burn
length from the burner must not reach the
side of the cushion opposite the burner. The
burn length must not exceed 17 inches. Burn
length is the perpendicular distance from the
inside edge of the seat frame closest to the
burner to the farthest evidence of damage to
the test specimen due to flame impingement,
including areas of partial or complete consumption, charring, or embrittlement, but
not including areas sooted, stained, warped,
or discolored, or areas where material has
shrunk or melted away from the heat source.
(5) The average percentage weight loss
must not exceed 10 percent. Also, at least
two-thirds of the total number of specimen
sets tested must not exceed 10 percent
weight loss. All droppings falling from the
cushions and mounting stand are to be discarded before the after-test weight is determined. The percentage weight loss for a specimen set is the weight of the specimen set
before testing less the weight of the specimen set after testing expressed as the percentage of the weight before testing.
(b) Test Conditions. Vertical air velocity
should average 25 fpmSection10 fpm at the top of
the back seat cushion. Horizontal air velocity should be below 10 fpm just above the
bottom seat cushion. Air velocities should be
measured with the ventilation hood operating and the burner motor off.

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