[Federal Register Volume 60, Number 22 (Thursday, February 2, 1995)]
[Rules and Regulations]
[Pages 6616-6629]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-2114]
[[Page 6615]]
_______________________________________________________________________
Part V
Department of Transportation
_______________________________________________________________________
Federal Aviation Administration
_______________________________________________________________________
14 CFR Part 25 et al.
Improved Flammability Standards for Materials Used in the Interiors of
Transport Category Airplane Cabins; Final Rule
Federal Register / Vol. 60, No. 22 / Thursday, February 2, 1995 /
Rules and Regulations
[[Page 6616]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Parts 25, 121, and 135
[Docket No. 26192, Amendments Nos. 25-83, 121-247 and 135-55]
RIN 2120-AD28
Improved Flammability Standards for Materials Used in the
Interiors of Transport Category Airplane Cabins
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: These amendments clarify standards adopted in 1986 concerning
the flammability of components used in the cabins of certain transport
category airplanes. This action is being taken to preclude costly,
unintended changes to airplane interiors. The clarifications, which are
applicable to air carriers, air taxi operators and commercial
operators, as well as manufacturers of such airplanes, will result in
more appropriate, consistent application of those standards.
EFFECTIVE DATE: March 6, 1995.
FOR FURTHER INFORMATION CONTACT: Gary L. Killion, Manager, Regulations
Branch, ANM-114, Transport Airplane Directorate, Aircraft Certification
Service, FAA, 1601 Lind Avenue Southwest, Renton, Washington 98055-
4056; telephone (206) 227-2114.
SUPPLEMENTARY INFORMATION:
Background
These amendments are based on Notice of Proposed Rulemaking (NPRM)
90-12, that was published in the Federal Register on April 12, 1990 (55
FR 13886).
As discussed in the notice, Amendments 25-61 and 121-189 (51 FR
26206, July 26, 1986) were adopted to upgrade the flammability
standards for materials used in the interiors of transport category
airplanes. The improved flammability standards were developed following
a research and development program managed and conducted primarily at
the FAA Technical Center in Atlantic City, New Jersey, to study
aircraft fire characteristics and develop practical test methods. Among
the tests conducted at the Technical Center were full-scale fire tests
using the fuselage of a military C-133 configured to represent a wide-
body jet transport airplane. The test conditions simulated
representative post-crash external fuel-fed fires. Numerous laboratory
tests were also conducted to correlate possible material qualification
test methods with the full-scale tests. As a result of those tests, the
Ohio State University (OSU) radiant rate-of-heat-release apparatus was
determined to be the most suitable for material qualification. These
tests led to the adoption of Amendment 25-61.
Amendment 25-61 established flammability standards for transport
category airplanes with passenger seating capacities of 20 or more and
specified the test method and apparatus to be used in showing
compliance with those standards. It specified that interior ceiling and
wall panels (other than lighting lenses), partitions, and the outer
surfaces of galleys, large cabinets and stowage compartments (other
than underseat stowage compartments and compartments for stowing small
items such as magazines and maps) must meet the new standards. As
outlined in the amendment, an average of three or more test specimens
must not exceed 65 kilowatts per square meter peak heat release nor 65
kilowatt minutes per square meter total heat release during the first
two minutes of sample exposure time (65/65) when tested using the OSU
test apparatus. These acceptance criteria were chosen in order to
produce a significant retardation of the flashover event which controls
occupant survivability, as experienced in the full-scale testing.
(Burning cabin materials give off unburned gases that collect in the
upper portions of the cabin. After a very short time, these unburned
gases are heated to the point where they ignite and burn
instantaneously. When this occurs, the temperature in the whole cabin
becomes so hot that survival is impossible for anyone remaining in the
cabin. This phenomenon, known as flashover, also makes further survival
impossible by consuming the oxygen in the cabin.)
Because Amendment 25-61 applies explicitly only to airplanes for
which an application for type certificate is made after August 20,
1986, Amendment 121-189 to Part 121 of the FAR was also adopted to
require operators of certain other airplanes used in air carrier or
commercial service to meet the new 65/65 standards. Those airplanes
must meet the new standards if they were newly manufactured after
August 19, 1990. Airplanes type certificated on or after January 1,
1958, and manufactured prior to August 20, 1990, must also comply with
the new standards upon the first substantially complete replacement of
the specified cabin interior components on or after the latter date.
Although Part 135 was not amended at that time, air taxi and
commercial operators of large airplanes are required to comply as well
because Sec. 135.169 incorporated the newly adopted provisions of Part
121 by reference.
At the time the amendments were adopted, the FAA understood that
some persons were planning to install components which, even though
they would meet the previously existing requirements of Part 25 for
flammability, were more flammable than the components that were in
general use at that time. In order to preclude a possible degradation
in the flammability characteristics of the cabin interiors, Amendment
121-189 also established interim standards of 100 kilowatts per square
meter peak heat release and 100 kilowatt minutes per square meter total
heat release (100/100). The interim standards are applicable to
airplanes manufactured during the two-year period prior to August 20,
1990; and, unless there is a substantially complete replacement of the
specified cabin interior components after August 19, 1990, they will
remain applicable to those airplanes as long as they are operated under
the provisions of Part 121 or Part 135. (If there is a substantially
complete replacement on or after August 19, 1990, the definitive 65/65
standards would be applicable.) In addition, the interim standards are
also applicable to airplanes in which there is a substantially complete
replacement of the specified interior components during that two-year
period.
Prior to the adoption of Amendment 121-189, Sec. 121.312 required
certain airplanes to meet earlier flammability standards upon the first
substantially complete replacement of the cabin interior. (Note that
this earlier rulemaking refers to a substantially complete replacement
of all cabin interior components, while the later rulemaking refers to
a substantially complete replacement of the specified interior
components. Whether certain other interior components, e.g., seat
cushions and flooring, are replaced is not relevant to whether there is
a substantially complete replacement in the latter case. Also, the
earlier rulemaking applies to all airplanes while the later rulemaking
applies only to airplanes with 20 or more passengers.) This earlier
requirement is partially superseded if there is a substantially
complete replacement of the interior components specified in
Sec. 25.853 (a-l) after August 19, 1988. It does, however, remain
applicable insofar as interior components not specified in
Sec. 25.853(a-l) are concerned. The earlier requirement also remains
applicable to airplanes in which there has not been a substantially
complete
[[Page 6617]]
replacement of the cabin interior since August 19, 1988, and to
airplanes with 19 or fewer passengers.
The date of manufacture, as used in Sec. 121.312, is the date on
which inspection records show that an airplane is in a condition for
safe flight. This is not necessarily the date on which the airplane is
in conformity to the approved type design, or the date on which a
certificate of airworthiness is issued, since some items not relevant
to safe flight, such as passenger seats, may not be installed at that
time. It could be earlier, but would be no later than the date on which
the first flight of the airplane occurs.
For reasons discussed in the preamble to that amendment, Amendment
25-66 was adopted (53 FR 37542, September 27, 1988) to make minor
refinements in the test procedures and apparatus required to show
compliance with the standards adopted by Amendment 25-61 and to add a
requirement for smoke testing. Amendment 121-198, which was adopted at
the same time, added a provision allowing deviations to be granted for
certain components.
In the preamble to Amendment 25-61, the FAA noted that the new heat
release standards apply to all large-surface cabin interior components,
such as sidewalls, ceilings, bins and partitions, and galley
structures. It was also noted that the new standards do not apply to
smaller items because their small masses would preclude significant
contributions to the total heat release in the cabin area. The FAA has
received a number of requests for clarification as to the maximum size
a component may be without having to comply with the new heat release
standards.
The distinction between parts with large surface areas, which must
meet the new standards, and those with smaller surface areas is very
difficult because of the size of the cabin and other factors that may
vary from one airplane to another. For example, a specific component
might be insignificant when installed in a large wide-body airplane
because it would make a minor contribution to the overall flammability
of the area of the cabin in which it is installed. On the other hand,
it might represent a major contribution when installed in a smaller
transport category airplane. The proximity of the component to a
potential source of fire, such as an exit or galley, is also a
consideration. It is not possible to cite a specific size that will
apply in all installations; however, as a general rule, components with
exposed-surface areas of one square foot or less may be considered
small enough that they do not have to meet the new standards.
Components with exposed-surface areas greater than two square feet may
be considered large enough that they do have to meet the new standards.
Those with exposed-surface areas greater than one square foot, but less
than two square feet, must be considered in conjunction with the areas
of the cabin in which they are installed before a determination could
be made.
Discussion
Since the time Amendments 25-61 and 121-189 were adopted, the FAA
became aware of four areas in which the wording of the new rules does
not clearly reflect the intent of the agency as discussed in the
preamble to those amendments. Because the new rules do not clearly
reflect the intent in those areas and because the comments that were
received may have been based on the intent, as expressed in the
preambles, rather than the literal wording of the rules, the following
clarifications were proposed in Notice 90-12.
Cabin windows and clear vision panels in cabin partitions: The
preamble to Amendments 25-61 and 121-189 states, ``The new flammability
standards do not apply to transparent or translucent components such as
lenses used in interior lights and illuminated signs, and window anti-
scratch panels, because of the lack of materials which will meet the
flammability standards and still have the light transmissibility
characteristics which are vital in emergency situations.'' Although not
specifically mentioned in the earlier rulemaking, transparent panels
are sometimes inserted in cabin partitions to enhance cabin safety. For
example, they are sometimes used to provide seated flight attendants a
clear, unobstructed view of the cabin or to provide passengers a view
of an exit as an aid to an emergency evacuation. As in the case of
lighting lenses and windows, the need for transparent partition panels
that enhance cabin safety outweighs the increased safety provided by
components that meet the new flammability standards considering the
small area such transparencies would involve. In order to preclude
confusion concerning the applicability of the standards to such
transparent or translucent panels, Sec. 25.853(a-l) (1) and (2) were
proposed to read, ``Interior ceiling and wall panels, other than
lighting lenses and windows,'' and, ``Partitions, other than
transparent panels needed to enhance cabin safety,'' respectively. The
maximum size of a transparent panel would, of course, be limited to
that which is actually needed to enhance cabin safety.
It was noted that the FAA would consider further rulemaking to
require those components to meet the new flammability standards should
materials capable of meeting the new flammability standards and having
the necessary light transmissibility characteristics for use as
windows, etc., be developed later.
Galleys: As currently worded, Sec. 25.853(a-1) states that the new
flammability standards apply to the ``outer surfaces of galleys.'' This
phrase was intended to make an exception for the interior surfaces of
galley cabinets, etc., that would not be exposed to a cabin fire. It is
ambiguous, however, because most galleys are not isolated from the main
cabin by a door. While one might consider the surfaces of a galley
working are to be ``inner surfaces,'' they are actually outer surfaces
in most installations in the sense that they could be exposed to a
cabin fire. In addition, the inner walls of the galley cart cavity or
standard container cavity may also be exposed on some lightly loaded
flights when there is not a full complement of carts or containers on
board. In order to preclude any confusion in this regard, it was
proposed that Sec. 25.853(a-1) would be amended to clarify that any
galley surface exposed to the passenger cabin must meet the new
standards.
Isolated compartments: Unlike previously existing paragraphs (a)
and (b) of Sec. 25.853, the new flammability standards of paragraph (a-
1) were intended to apply only to the passenger cabin and not to
compartments that are isolated from the passenger cabin. Due, however,
to the organization of Sec. 25.853(a-1), if taken literally, the new
standards also pertain to each compartment occupied by crew (including
one occupied only on a temporary basis) or passengers regardless of
whether the particular compartment is isolated from the passenger
cabin.
Neither the research and development program nor the regulatory
evaluations on which the new flammability standards were based
considered that compartments isolated from the passenger cabin (or
cabins in the case of airplanes with passenger cabins located on two
different decks) would have to comply with the new standards. Unlike
most galleys located in the main cabin, remote galleys and other
compartments, such as lavatories, pilot compartments and crew rest or
sleeping areas, are generally isolated from the passenger cabin by at
least a door. In some instances, they are located on separate decks.
They would, therefore, not be exposed to a cabin fire until well after
[[Page 6618]]
flashover had occurred in the cabin and egress was no longer possible.
Should an external fire enter the airplane at one of those
compartments, the flammability of the materials used in them would not
directly affect the cabin due to their isolation. As stated in the
earlier rulemaking, the new standards address a post-crash, external
fuel-fed fire situation. With the exception of the pilot compartment,
it can be assumed that such compartments would not be occupied by
passengers or crewmembers during a post-crash situation.
Although the rulemaking was undertaken to address a post-crash
scenario, there is also the question of whether or not requiring the
lavatories to meet the new flammability standards would enhance safety
significantly in the event a fire originated in a lavatory during
flight. This question is particularly pertinent in light of the
recently adopted ban on smoking on domestic airline flights. Although
some persons might be more tempted to smoke illicitly in a lavatory
during such flights, the lavatory smoke detector required by recently
adopted Amendment 121-185 (50 FR 12726, March 29, 1985) serves as a
deterrent and provides warning of illicit smoking to the crew. In
addition, the new standards would not apply to many of the components
in a lavatory due to their small size. The doors and most sidewalls
have to meet the new standards regardless of whether the new standards
are applicable to lavatories because their outer sides also form
surfaces of the passenger cabin. Some portions of the lavatory are
generally constructed of fireproof stainless steel due to functional
considerations. Requiring the few remaining large components to meet
the new standards would have very little impact on the overall
flammability of the lavatory and would not significantly enhance safety
in the event of an inflight fire.
Pilot compartments are generally isolated from the passenger cabin
by a bulkhead and door. Although they are obviously occupied full-time,
requiring them to meet the new standards would not significantly
enhance safety in the event of an inflight fire for essentially the
same reasons. Pilot compartments are generally constructed of many
small components which would not have to meet the new standards due to
their small size. The bulkhead and entry door have to meet the new
standards regardless of whether they are applicable to the pilot
compartment because the aft sides of those components also form
surfaces of the passenger cabin. As in the case of the lavatories,
requiring the few remaining large components to meet the new standards
would have very little impact on the overall flammability of the pilot
compartment. Although there is no smoke detector required, a fire would
be detected immediately by the flight crewmembers. In addition, at
least one hand fire extinguisher must be conveniently located in the
pilot compartment in accordance with Sec. 25.851.(a)(6).
In view of these considerations, it was proposed that Sec. 25.853
would be amended to clarify that compartments that are isolated from
the cabin need not meet the standards. Sidewalls, doors etc., that
separate such compartments from the passenger cabin would, of course,
have to meet the new standards because their outer sides also form
surfaces of the passenger cabin.
Galley carts and other rotatable galley equipment: The earlier
rulemaking contained the statement, ``Service items, such as pillows or
blankets, magazines, food, and alcoholic beverages, are not part of the
certification process and would not have to meet the new flammability
standard.'' Galley carts are considered to be service items; however,
unlike the items cited in the preamble statement, they are generally
approved as part of the airplane type design. Although the new
flammability standards do not apply expressly to galley carts, it was
intended that they would apply implicitly to the extent that, when
stowed, the galley carts form exterior surfaces of the galley.
Typically, at least one end of each cart remains exposed and forms a
galley surface while the cart is stowed. In addition to galley carts,
these are galley standard containers used for various meal courses,
beverages, plates, etc., that also form galley surfaces when stowed.
Operators have pointed out that galley carts are removable items
that are rotated from one airplane to another with each flight. In this
regard, they note that their fleets will include older airplanes that
are not required to meet the new standards, as well as new airplanes
(or airplanes in which the interiors have been replaced) that will be
required to meet the new standards. They further note that the carts
are loaded before a flight by persons, usually independent caterers,
who have no way of knowing whether or not the airplane that will be
used on a particular flight is required to meet the new standards.
Unless all existing noncomplying galley carts are replaced with galley
carts that meet the new standards, there is no practical means to
ensure that galley carts meeting the new standards will be loaded on
the airplanes that are required to have them. It is estimated that
there are now approximately 125,000 galley carts in use with the U.S.
air carrier fleet. Typically, the cost per cart ranges from $800 to
$3,500; and the service life is about eight to ten years. While it is
feasible to replace the existing carts on an attrition basis, it would
be impractical to produce enough galley carts meeting the new standards
in time to meet the established deadlines. In addition, such immediate
replacement would be very costly. The operators note that they would
have commented accordingly had they not believed that, as service
items, galley carts did not have to meet the new standards.
The galley standard containers are also rotated from airplane to
airplane; and they, too, are filled prior to the flight by persons who
have no way of knowing whether the airplane that will be used on the
flight is one required to meet the new standards. While the cost of
each galley standard container would be less than that of a beverage
cart, replacing the entire inventory of containers would be very
costly.
Although it was intended that the exposed surfaces of stowed galley
carts and standard containers should meet the new standards, the FAA
has concluded, upon further review, that it was not clearly stated that
the galley carts and containers would be required to comply. The FAA
does, however, consider that the exposed surfaces of stowed galley
carts and standard containers must ultimately meet the new flammability
standards. It was, therefore, proposed that Sec. 25.853(a-1) would be
amended to specifically require the exposed surfaces of those
components to meet the new standards.
The FAA concurs that unless all carts and containers are replaced,
it would be extremely difficult to ensure that galley carts and
standard containers meeting the new standards are loaded on the
airplanes that are required to meet them. Furthermore, the immediate
replacement of all galley carts and standard containers would be
logistically impossible and would present an unreasonable economic
burden. If, on the other hand, galley carts and standard containers
that meet the new standards are acquired at a rate commensurate with
the rate at which new airplanes are acquired (and interiors of older
airplanes are replaced), it can be assumed that the overall level of
safety of the air carrier fleet will not be adversely affected by
intermixing carts and containers complying with the new standards with
those that do not. The small decrement of safety that would be suffered
due to
[[Page 6619]]
the use of noncomplying carts and containers in an airplane that must
meet the new standards would be compensated by an increment of safety
enjoyed due to the use of complying carts and containers in another
airplane that is not required to meet them. It was, therefore, proposed
that Sec. 121.312 would be amended to allow such intermixing of galley
carts and standard containers, provided that all carts and containers
manufactured after a specified date meet the new standards.
Other changes: Certain minor refinements in the test apparatus and
procedures were identified; and it was proposed that Appendix F of Part
25, including the associated figures, would be revised accordingly. The
proposed refinements would not preclude the use of materials previously
found to be acceptable under the new standards; nor enable the use of
materials previously found unacceptable; however, they would improve
the repeatability of test results from one test run to another and from
one laboratory to another. Other minor nonsubstantive editing changes
would be made for consistency in style. Nonsubstantive editing changes
would also be made to Sec. 25.853 for clarity.
It was also proposed that the organization and language of
Sec. 121.312(a) would be revised for clarity.
As noted above, Part 135 was not amended at the time the new
standards were adopted; however, they are equally applicable to Part
135 operators because Sec. 135.169(a) incorporates the provisions of
Sec. 121.312 by cross reference. Since that time, it has come to the
attention of the FAA that the practice of incorporating certain
provisions of Part 121 in Part 135 by cross reference may cause
confusion. In order to preclude any confusion in this regard, it was
proposed that Part 135 would be amended to include the new standards
explicitly rather than by reference. Because Part 135 operators are
already required to meet these standards due to the incorporation by
cross reference, this change would not place any additional burden on
any person.
The reference to ``November 26, 1987'' in Sec. 121.312(b) is no
longer relevant because that date has already passed. It would,
therefore, be removed for simplification. The redundant reference to
Appendix F of Part 25 would also be removed from Sec. 121.312(b) for
simplification and consistency with the editorial style used in
Sec. 121.312(a). (Appendix F, Part II, is incorporated by cross
reference in Sec. 25.853(c); and Appendix F, Part IV, is incorporated
by cross reference in Sec. 25.853(a-1).)
Since the time Notice 90-12 was issued, Amendment 25-72 was adopted
(55 FR 29756, July 20, 1990). Although no substantive changes to
Sec. 25.853 were adopted, the requirements of that section were
rearranged considerably for clarity, and the test acceptance criteria
formerly contained in that section were transferred to Part I of
Appendix F. It is, therefore, necessary to make a number of
nonsubstantive conforming changes for consistency with Sec. 25.853 in
its present format.
Among the changes made to Sec. 25.853 as a result of the adoption
of Amendment 25-72 was the transfer of the seat cushion flammability
standards from former Sec. 25.853(c) to new Sec. 25.853(b). It has been
brought to the attention of the FAA that this change is causing
considerable confusion.
Seats are frequently transferred from one airplane to another;
therefore, as a practical matter, they must be marked to show that
their cushions comply with the flammability standards. With the change
in section number, the previous markings indicating compliance with
Sec. 25.853(c) are no longer accurate. In order to eliminate further
confusion in that regard, Sec. 25.853(b) has been marked ``Reserved,''
and the seat cushion flammability standards have been transferred back
to Sec. 25.853(c).
For convenience, the proposed changes to Sec. 25.853 are discussed
below both in terms of their identity in Notice 90-12 and as rearranged
for conformity with the changes resulting from the adoption of
Amendment 25-72.
Discussion of Comments
Seven commenters responded to the request for comments contained in
Notice 90-12. These included manufacturers, a foreign airworthiness
authority, and organizations representing manufacturers, airlines, and
airline employees.
One commenter notes that the restructuring and numbering of
Sec. 25.853 may have inadvertently excluded such items as lighting
lenses, windows, transparent panels needed to enhance cabin safety,
etc., from compliance with any of the flammability standards of
Sec. 25.853. The FAA concurs that the wording proposed in Notice 90-12
could have led to an incorrect interpretation of that nature. Section
25.853 is, therefore, changed by transferring the statement ``Except as
provided * * *'' to Sec. 25.853(d), which would have been
Sec. 25.853(a-1) as proposed in Notice 90-12.
One commenter opposes the proposal to clarify that compartments
isolated from the cabin are not required to meet the heat release
standards of Sec. 25.853(a-l). The commenter states that all
compartment components should be of the same standard and that meeting
the same standard would ensure that the net amount of material
contributing to fire development and propagation is at the absolute
minimum. In that regard, the commenter cites the accident involving a
McDonnell Douglas DC-9 operated by Air Canada on June 2, 1983, at the
Greater Cincinnati Airport, Covington, Kentucky. The commenter notes
that, while the origin of the fire that destroyed the airplane could
not be identified, the lavatory compartment's interior material was the
primary source of fuel and that the fire burned undetected for almost
15 minutes before the smoke was first noticed. The commenter asserts
that requiring the compartment to meet the same low heat release
standards as the main cabin would significantly reduce the amount of
fuel available for such a fire.
Contrary to the commenter's assertion, requiring all lavatory
components to meet the new standards for heat release would not
significantly reduce the amount of fuel available for a fire
originating in the lavatory. As noted above under Background, the heat
release standards do not apply to small surface-area components. As
further noted above under Discussion, many of the components in the
lavatory are small enough that they would not have to meet the new
standards in any event. The doors and most sidewalls have to meet the
new standards regardless of whether the new standards are applicable to
lavatories because their outer sides also form surfaces of the
passenger cabin. Some portions of the lavatory are generally
constructed of stainless steel due to functional considerations.
Stainless steel is, of course, fireproof. Requiring the few remaining
large components to meet the new standards would have very little
impact on the overall flammability of the lavatory and would not
significantly enhance safety in the event of an inflight fire.
In the accident cited by the commenter, smoke was discovered coming
from the left-hand lavatory in the aft cabin while the airplane was
enroute from Dallas, Texas to Montreal, Quebec. An emergency landing
was not made until 17 minutes later. By that time, the fire and smoke
had grown in intensity to the point that only half of the 46 occupants
were able to escape. As noted in their official accident report, NTSB/
AAR-86/02, the National Transportation Safety Board determined that the
probable causes of the accident were a fire of unknown origin, an
underestimate of the fire severity, and
[[Page 6620]]
misleading fire progress information provided to the captain.
Considering the few lavatory components that would be affected and the
time that the fire had been burning prior to the emergency landing, it
is unlikely that the outcome of the accident would have been more
favorable if the lavatory of that airplane had met the new heat release
standards.
Subsequent to the accident, the FAA adopted Amendments 25-58 and
121-183 (49 FR 43182, October 26, 1984), and 25-59 and 121-184 (49 FR
43188, October 26, 1984), that require, respectively, low-level
lighting to enable occupants to locate emergency exits in smoke-filled
cabins and new flammability standards for seat cushions. Unlike the
heat release standards of Amendment 25-61, the new flammability
standards for seat cushions are designed to slow the progression of a
fire through the cabin. The standards of Amendment 25-61 are, on the
other hand, designed to reduce the overall release of heat into the
cabin during a post-crash fire situation and provide more time for
egress before flashover makes further escape impossible. Amendment 121-
185 (50 FR 12726, March 29, 1985) was also adopted to require each
lavatory to be equipped with a smoke detection system, or equivalent,
and a fire extinguisher that discharges automatically upon the
occurrence of a fire in the trash receptacle. In addition, the
amendment requires the passenger cabins of certain airplanes to be
equipped with additional hand fire extinguishers, some of which must
contain the improved agent Halon 1211.
The commenter also notes that all compartments with essential
systems adjacent to their surfaces should be required to meet the heat
release standards of Sec. 25.853(a-1) in order to protect the essential
conductors of those systems from the high heat releases of burning
interior materials.
The commenter appears to be confusing the standards for heat
release with other standards for flame resistance. As noted above, the
heat release standards are designed to reduce the overall release of
heat into an area and thereby delay the time until flashover occurs. It
is assumed, on the other hand, that the insulation of electrical wiring
and cables could be enveloped by flame. They must, therefore, be tested
by actual application of flame to the insulation surface.
The same commenter recommends that, if an isolated compartment does
not have to meet the heat release standards, the doors separating the
compartment from the main cabin should be able to contain the heat and
smoke in the isolated compartment for at least five minutes. (Such
doors would be `fire-resistant' as defined in Part 1 of the FAR.)
The commenter's recommendation is apparently based on the
assumption that there will be an uncontrollable fire originating from
an isolated compartment. In view of the fire protection measures that
have been adopted for lavatories since the above noted accident, there
is no evident need for fire-resistant lavatory doors. Furthermore,
service history does not support a need for such doors to other
isolated compartments. The exception proposed as Sec. 25.853(a-2) is,
therefore, adopted as Sec. 25.853(e).
One commenter recommends that Sec. 25.853(a-1)(1) be amended to
read, ``other than lighting lenses, illuminated signs and windows,''
since illuminated signs are discussed in the preamble to Notice 90-12
as examples of excluded items. While it is true that the illuminated
portions of passenger information signs are not required to meet the
heat release standards of that section, it is not necessary to refer to
them specifically in Sec. 25.853(a-1)(1) because they are ``lighting
lenses.'' Proposed Sec. 25.853(a-1)(1) is adopted as Sec. 25.853(d)(1).
The same commenter and one other recommend that Sec. 25.853(a-2) be
clarified by adding ``lavatories'' to the list of compartments whose
interiors are excluded. Unlike the illuminated signs discussed above,
it may not be as clear that lavatories are considered isolated
compartments and, as such, are already excluded. Proposed
Sec. 25.853(a-2) is, therefore, changed to read, ``* * * such as pilot
compartments, galleys, lavatories, crew rest quarters, cabinets and
stowage compartments, * * *,'' and adopted as Sec. 25.853(e).
One commenter suggests that Sec. 25.853(a-2) should stipulate ``20
or more passengers.'' Since the only purpose of this paragraph, adopted
as paragraph (e), is to make an exception to paragraph (a-1), adopted
as paragraph (d), which is already so limited, there is no need to
repeat this limitation of applicability.
Because the flammability standards of Sec. 25.853(d), formerly
Sec. 25.853(a-1), are applicable only to airplanes with 20 or more
passengers, some persons have mistakenly assumed that the seat cushion
standards of Sec. 25.853(c) are also applicable only to airplanes with
20 or more passengers. To preclude any confusion in this regard, the
phrase, ``regardless of the passenger capacity of the airplane,'' has
been added to Sec. 25.853 (a) and (c).
Another commenter suggests that Part IV of Appendix F should be
amended to permit the use of the optional 14-hole upper pilot burner
that has been found satisfactory. Actually, the use of this optional
burner has already been accepted by the FAA under the equivalent safety
provisions of Sec. 21.21(b)(1). The FAA notes that test data obtained
during testing with the three-hole burner are sometimes invalidated
because the pilot burner would not remain lighted for the entire 5-
minute duration of the test. With the optional 14-hole burner, there is
a greater probability of reigniting any flamelets that might extinguish
during a test. Because the 14-hole burner may be preferable in some
instances, Part IV is amended to describe the optional use of that
burner, as suggested by the commenter. Testing with this optional
burner is already permitted under the equivalent safety provisions of
Sec. 21.21(b)(1); therefore, this is a minor nonsubstantive change that
places no additional burden on any person.
Paragraph (b)(8) states that the pilot burners must remain lighted
for the entire duration of the test. In regard to the difficulties
experienced in keeping the three-hole upper pilot burner lighted for
the entire duration of the test, the FAA proposed to add the statement,
``Intermittent pilot flame extinguishment for more than 3 seconds would
invalidate the test results.'' The same commenter notes that further
clarification is required. According to the commenter, it is normal for
some of the upper pilot-burner flamelets to be extinguished for periods
that can exceed three seconds when samples containing flame retardants
are tested. The commenter notes that the results of such tests have
been considered acceptable provided some of the flamelets have remained
lighted.
The FAA concurs that it is not necessary for each flamelet of the
three-hole upper pilot burner to remain lighted for the entire 5-minute
duration of the test; however, test results may be invalidated if two
flamelets are unlighted for more than 3 seconds. In order to preclude,
such intermittent flamelet extinguishment, the FAA has permitted
applicants to install an igniter. Intermittent flame extinguishment has
not posed a problem with the optional 14-hole upper pilot burner since
it was developed to preclude flame extinguishment. Paragraph (b)(8) is,
therefore, changed to read, ``Since intermittent pilot flame
extinguishment for more than 3 seconds would invalidate the test
results, a spark igniter may be installed to ensure that the burners
remain lighted.'' Paragraph
[[Page 6621]]
(e)(8), which is considered a more appropriate location than paragraph
(b)(8), is amended to clarify the requirements for burners and
flamelets to remain lighted.
Part IV, paragraph (e)(3) states that the proper air flow may be
set and monitored by either an orifice meter or a rotometer. Because of
difficulties experienced in setting and monitoring the air flow with a
rotometer, the FAA proposed in Notice 90-12 to amend that paragraph to
refer only to an orifice meter. The same commenter cited the successful
use of a rotometer by the National Research Council of Canada and
recommended that the reference to a rotormeter be retained in that
paragraph. While the use of a rotometer may be successful in some
instances, the FAA does not have sufficient information at this time to
conclude that a rotometer is acceptable on a general basis. It is,
therefore, not considered appropriate to specifically cite the
rotormeter in that paragraph as an acceptable alternative means of
setting and monitoring air flow. The FAA does recognize, however, that
rotometers, or any other devices for that matter, may be improved to
the point that their use is acceptable. In that event, those devices
could be used under the equivalent safety provisions of
Sec. 21.21(b)(1).
The same commenter notes that the area of .02323 m2 specified
in the heat release equation of paragraph (f)(2) is based on a test
specimen size of 6 x 6 inches. Since the actual size of the sample is
150 x 150 mm, the commenter believes that an area factor of .0225
m2 should actually be used in the heat release equation.
Although the commenter is technically correct, the definitive 65/65
and the interim 100/100 standards were established based on the use of
a factor of .02323 m2. Furthermore all testing completed to date
has been based on the use of the .02323 factor. Changing the factor to
.0225 at this late date would mean that the 65/65 and 100/100 standards
would have to be changed to 67/67 and 103/103, respectively, in order
to preclude a degradation of the components approved for use in
airplane cabins. This would no doubt cause considerable confusion,
particularly when test results obtained with the .0225 factor are
compared with earlier test results obtained with the original .02323
factor.
The same commenter notes that considerable confusion is created by
the fact that dimensions of the the test apparatus are specified in
U.S. units in some instances and in metric units in others. The FAA
concurs. For clarity, part IV is revised to show dimensions in both
U.S. units and their metric equivalents. Other minor, nonsubstantive
changes are also made to Part IV for clarity.
Section 121.312(a) incorporates the heat release standards of
Sec. 25.853(a-1) by cross reference. Since the latter section applies
only to airplanes with passenger capacities of 20 or more,
Sec. 121.312(a) requires compliance with these heat release standards
only for airplanes with passenger capacities of 20 or more. As one
commenter notes, Sec. 121.312(a) can be misinterpreted to require
compliance for all transport category airplanes regardless of their
passenger capacity. In order to preclude possible confusion in this
regard, both Sec. 121.312(a) and newly adopted Sec. 135.170(b)(1) state
specifically that compliance is required only for airplanes with
passenger capacities of 20 or more.
Another commenter notes that Sec. 121.312(a) (1) through (6) and
the corresponding Sec. 135.170(b)(1) (i) through (vi) are complex and
difficult to understand. The FAA acknowledges that these sections are
very complex. This is due primarily to the fact that there are
differing requirements dependent on such factors as when the airplane
was type certificated, when it was manufactured, when there was a
substantially complete replacement of the cabin interior components,
etc. There is even a distinction between complete replacement of all
cabin interior components in one case and just those components
identified in Sec. 25.853(a-1) in another. The only way in which the
provisions of these sections could be significantly simplified would be
to require compliance for all airplanes at one time. While that would
simplify the regulatory language considerably, it would impose costly
additional burdens on some operators with no commensurate improvement
in safety. Nevertheless, minor nonsubstantive changes have been made
wherever possible to clarify these requirements.
Proposed Sec. 121.312(a)(8) states, in part, that ``* * * galley
carts and galley standard containers that do not meet the heat release
rate testing requirements * * * may be used * * * provided the galley
carts or standard containers were manufactured prior to August 20,
1990.'' One commenter believes that this section should refer to galley
carts and standard containers manufactured prior to a date two years
after the effective date of this amendment.
The FAA concurs that it is inappropriate to specify a date earlier
than the date on which this final rule becomes effective. The FAA does
not, however, agree that an additional two-year compliance time is
necessary. The amendment does not require galley carts and standard
containers manufactured after the specified date to comply. Instead, it
relieves operators of the burden of ensuring that only complying galley
carts and standard containers are loaded on airplanes that are required
to meet the new flammability standards provided the galley carts and
standard containers are manufactured prior to that date. Section
121.312(a)(8) and the corresponding Sec. 135.170(b)(viii) are,
therefore, changed to read, ``* * * provided the galley carts or
standard containers were manufactured prior to March 6, 1995.
One commenter believes that there should be a specific definition
of what constitutes ``substantially complete replacement'' as stated in
Sec. 121.312. The commenter expresses concern that the definition
should allow for the individual replacement of cabin interior
components without the mandatory replacement of all components at the
same time.
``Complete replacement,'' as used in Sec. 121.312 and newly adopted
Sec. 135.170(b), means that all of the affected components in the cabin
are replaced. (As noted above under Background, whether the other
components that are not affected, e.g. seat cushions and flooring, are
replaced is not relevant.) The qualifying word ``substantially'' was
added simply to prevent operators from avoiding compliance by not
replacing a minor, inconsequential cabin component and claiming that
there had not been a ``complete replacement.'' Section 212.312 does,
therefore, permit individual replacement of cabin interior components
without the mandatory replacement of all components at the same time.
This, of course, assumes that the cabin components did not already have
to meet the heat release standards because of the date of manufacture
of the airplane or because they had been completely replaced
previously. It should also be noted that removing components for
refinishing and reinstalling them in the same airplane is considered
``refurbishment,'' not ``replacement.''
Proposed Sec. 135.170(b) states, ``No person may operate a large
airplane unless * * *'' Several commenters note that Part 23 commuter
category airplanes are ``large airplanes,'' as defined by Part 1 of the
FAR, and, as such, would be required to meet the new flammability
standards contained in that section. Another commenter has a similar
concern that proposed
[[Page 6622]]
Sec. 135.170(b) would appear to add substantial requirements for
airplanes type certificated under the provisions of Part 23 and Special
Federal Aviation Regulations (SFAR) No. 41.
Although commuter category airplanes may be large enough to be
``large airplanes'' as defined by Part 1, they are not permitted to
carry more than 19 passengers. Since the flammability standards of
Sec. 135.170(b) apply only to airplanes with more than 19 passengers,
commuter category airplanes would not be required to comply even though
they may be ``large airplanes.'' SFAR No. 41 provides that, contrary
provisions of Part 1 notwithstanding, airplanes certificated under the
provisions of that SFAR are considered to be ``small airplanes'' in
regard to compliance with Part 135. Furthermore they, like commuter
category airplanes, are not permitted to carry more than 19 passengers.
Since neither commuter category airplanes nor those type
certificated under the provisions of SFAR No. 41 are permitted to carry
more than 19 passengers, there is no need to amend Sec. 135.170(b) of
specifically exclude those airplanes. Specifically stating in
Secs. 121.312(a) and 135.170(b)(1) that only airplanes with 20 or more
passengers seats are required to comply, as discussed above, will
preclude confusion in this regard.
One commenter reiterates a belief that the seat cushion
flammability standards of Sec. 25.853(c) are an unnecessary burden for
operators of small transport category airplanes with passenger seating
capacities of fewer than 19 passengers. The commenter is referring in
this regard to the provisions of Sec. 121.312 which were previously
incorporated by cross reference in Sec. 135.169 and now are stated
explicitly as new Sec. 135.170(b)(2). Section 121.312(b) and the new
Sec. 135.170(b)(2), in turn specify that the operator must have seat
cushions that meet the flammability standards of Sec. 25.853(c). That
issue has already been addressed by FAA in earlier rulemaking and is
not related, in any substantive manner, to the present rulemaking.
Another commenter notes an inadvertent error in proposed
Sec. 135.169(a) in that it would incorporate Sec. 121.311 by cross
reference. The intent was to move the no longer needed reference to
Sec. 121.312, not to replace it with Sec. 121.311. Section 135.169(a)
is corrected accordingly.
Regulatory Evaluation
Regulatory Evaluation
Exeuctive Order 12291, dated February 17, 1981, directs Federal
agencies to promulgate new regulations or modify existing regulations
only if potential benefits to society for each regulatory change
outweigh potential costs. This section summarizes the full regulatory
evaluation prepared by the FAA that provides more detailed estimates of
the economic consequences of this regulatory action.
The evaluations prepared for Amendments 25-61 and 121-189, and
Amendments 25-66 and 121-198 remain unchanged by this rule with respect
to costs and benefits, regulatory flexibility determinations, and trade
impact assessment.
None of the amendments in this rule will generate significant costs
or benefits. In part, the rule clarifies the original intent of the
earlier amendments. The changes to the test apparatus and procedures
for determining heat release rate are minor refinements that will
result only in negligible costs and benefits. The amendment to Part 135
is a nonsubstantive change that incorporates existing requirements
explicitly rather than by cross reference. The remaining changes are
editorial or conforming in nature.
Regulatory Flexibility Determination
The Regulatory Flexibility Act of 1989 (RFA) was enacted by
Congress to ensure that small entities are not unnecessarily or
disproportionately burdened by Government regulations. The RFA requires
a Regulatory Flexibility Analysis if a rule has a significant economic
impact, either detrimental or beneficial, on a substantial number of
small entities. FAA Order 2100.14A, Regulatory Flexibility Criteria and
Guidance, established threshold cost values and small entity size
standards for complying with RFA review requirements in FAA rulemaking
actions. The FAA has determined that this rule will not have a
significant economic impact on a substantial number of small entities.
International Trade Impact Analysis
This rule will not have an adverse impact either on the trade
opportunities of U.S. operators or manufacturers of transport category
airplanes doing business abroad, or on foreign operators or aircraft
manufacturers doing business in the United States.
Federalism Implications
The regulations adopted herein will not have substantial direct
effects on the States, on the relationship between the national
government and the States, or on the distribution of power and
responsibilities among the various levels of government. Therefore, in
accordance with Executive Order 12612, it is determined that this final
rule will not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
Conclusion: Because the regulations adopted herein are expected to
result only in negligible costs, the FAA has determined that this final
rule is not major as defined in Executive Order 12291. Because this is
an issue that has not prompted a great deal of public concern, this
final rule is not considered to be significant as defined in Department
of Transportation Regulatory Policies and Procedures (44 FR 11034,
February 26, 1979). In addition, since there are no small entities
affected by this rulemaking, it is certified, under the criteria of the
Regulatory Flexibility Act, that this final rule, at promulgation, will
not have a significant economic impact, positive or negative, on a
substantial number of small entities. The regulatory evaluation
prepared for Amendments 25-66 and 121-198 remains applicable and has
been placed on the docket. A copy of this evaluation may be obtained by
contacting the person identified under the caption FOR FURTHER
INFORMATION CONTACT.
List of Subjects
14 CFR Part 25
Aircraft, Air transportation, Aviation safety, Safety.
14 CFR Part 121
Air carriers, Aircraft, Airplanes, Air transportation, Aviation
safety, Common carriers, Flammable materials, Safety, Transportation.
14 CFR Part 135
Air carriers, Aircraft, Airplanes, Air transportation, Aviation
safety, Cargo, Hazardous materials, Mail, Safety, Transportation.
Adption of the Amendment
Accordingly, 14 CFR Parts 25, 121 and 135 of the Federal Aviation
Regulations (FAR) are amended as follows:
PART 25--AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES
1. The authority citation for Part 25 is revised to read as
follows:
Authority: 49 U.S.C. 106(g), 1344, 1354(a), 1355, 1421, 1423,
1424, 1425, 1428, 1429, 1430.
2. By revising Sec. 25.853 to read as follows:
[[Page 6623]]
Sec. 25.853 Compartment interiors.
For each compartment occupied by the crew or passengers, the
following apply:
(a) Materials (including finishes or decorative surfaces applied to
the materials) must meet the applicable test criteria prescribed in
Part I of Appendix F of this Part, or other approved equivalent
methods, regardless of the passenger capacity of the airplane.
(b) [Reserved]
(c) In addition to meeting the requirements of paragraph (a) of
this section, seat cushions, except those on flight crewmember seats,
must meet the test requirements of part II of Appendix F of this Part,
or other equivalent methods, regardless of the passenger capacity of
the airplane.
(d) Except as provided in paragraph (e) of this section, the
following interior components of airplanes with passenger capacities of
20 or more must also meet the test requirements of parts IV and V of
Appendix F of this Part, or other approved equivalent method, in
addition to the flammability requirements prescribed in paragraph (a)
of this section:
(1) Interior ceiling and wall panels, other than lighting lenses
and windows;
(2) Partitions, other than transparent panels needed to enhance
cabin safety;
(3) Galley structure, including exposed surfaces of stowed carts
and standard containers and the cavity walls that are exposed when a
full complement of such carts or containers is not carried; and
(4) Large cabinets and cabin stowage compartments, other than
underseat stowage compartments for stowing small items such as
magazines and maps.
(e) The interiors of compartments, such as pilot compartments,
galleys, lavatories, crew rest quarters, cabinets and stowage
compartments, need not meet the standards of paragraph (d) of this
section, provided the interiors of such compartments are isolated from
the main passenger cabin by doors or equivalent means that would
normally be closed during an emergency landing condition.
(f) Smoking is not to be allowed in lavatories. If smoking is to be
allowed in any other compartment occupied by the crew or passengers, an
adequate number of self-contained, removable ashtrays must be provided
for all seated occupants.
(g) Regardless of whether smoking is allowed in any other part of
the airplane, lavatories must have self-contained, removable ashtrays
located conspicuously on or near the entry side of each lavatory door,
except that one ashtray may serve more than one lavatory door if the
ashtray can be seen readily from the cabin side of each lavatory
served.
(h) Each receptacle used for the disposal of flammable waste
material must be fully enclosed, constructed of at least fire resistant
materials, and must contain fires likely to occur in it under normal
use. The capability of the receptacle to contain those fires under all
probable conditions of wear, misalignment, and ventilation expected in
service must be demonstrated by test.
3. By amending part IV of Appendix F to Part 25 by revising
paragraphs (a), (b)(1) through (6), (b)(8), (c)(1), (d) heading and
(d)(1), (d)(3), (e)(1) through (5), (e)(8), (f)(2), and by adding
paragraph (c)(3); transferring Figures 1 through 5 at the end of
Appendix F to the end of part IV of Appendix F and adding a heading
preceding the figures, and by removing Figure 1 of part IV and adding
Figures 1A and 1B in its place to read as follows:
Appendix F to Part 25
* * * * *
Part IV--Test Method to Determine the Heat Release Rate from Cabin
Materials Exposed to Radiant Heat.
(a) Summary of Method. Three or more specimens representing the
completed aircraft component are tested. Each test specimen is injected
into an environmental chamber through which a constant flow of air
passes. The specimen's exposure is determined by a radiant heat source
adjusted to produce, on the specimen, the desired total heat flux of
3.5 W/cm2. The specimen is tested with the exposed surface
vertical. Combustion is initiated by piloted ignition. The combustion
products leaving the chamber are monitored in order to calculate the
release rate of heat.
(b) * * *
(1) This apparatus is shown in Figures 1A and 1B of this part IV.
All exterior surfaces of the apparatus, except the holding chamber,
must be insulated with 1 inch (25 mm) thick, low density, high
temperature, fiberglass board insulation. A gasketed door, through
which the sample injection rod slides, must be used to form an airtight
closure on the specimen hold chamber.
(2) Thermopile. The temperature difference between the air entering
the environmental chamber and that leaving must be monitored by a
thermopile having five hot, and five cold, 24-guage Chromel-Alumel
junctions. The hot junctions must be spaced across the top of the
exhaust stack, .38 inches (10 mm) below the top of the chimney. The
thermocouples must have a .050 .010 inch (1.3
.3mm) diameter, ball-type, welded tip. One thermocouple must be located
in the geometric center, with the other four located 1.18 inch (30 mm)
from the center along the diagonal toward each of the corners (Figure 5
of this part IV). The cold junctions must be located in the pan below
the lower air distribution plate (see paragraph (b)(4) of this part
IV). Thermopile hot junctions must be cleared of soot deposits as
needed to maintain the calibrated sensitivity.
(3) Radiation Source. A radiant heat source incorporating four Type
LL silicon carbide elements, 20 inches (508 mm) long by .63 inch (16
mm) O.D., must be used, as shown in Figures 2A and 2B of this part IV.
The heat source must have a nominal resistance of 1.4 ohms and be
capable of generating a flux up to 100 kW/m\2\. The silicone carbide
elements must be mounted in the stainless steel panel box by inserting
them through .63 inch (16 mm) holes in .03 inch (1 mm) thick ceramic
fiber or calcium-silicate millboard. Locations of the holes in the pads
and stainless steel cover plates are shown in Figure 2B of this part
IV. The truncated diamond-shaped mask of .042.002 inch
(1.07.05mm) stainless steel must be added to provide
uniform heat flux density over the area occupied by the vertical
sample.
(4) Air Distribution System. The air entering the environmental
chamber must be distributed by a .25 inch (6.3 mm) thick aluminum plate
having eight No. 4 drill-holes, located 2 inches (51 mm) from sides on
4 inch (102 mm) centers, mounted at the base of the environmental
chamber. A second plate of 18 guage stainless steel having 120, evenly
spaced, No. 28 drill holes must be mounted 6 inches (152 mm) above the
aluminum plate. A well-regulated air supply is required. The air-supply
manifold at the base of the pyramidal section must have 48, evenly
spaced, No. 26 drill holes located .38 inch (10 mm) from the inner edge
of the manifold, resulting in an airflow split of approximately three
to one within the apparatus.
(5) Exhaust Stack. An exhaust stack, 5.25 x 2.75 inches (133 x 70
mm) in cross section, and 10 inches (254 mm) long, fabricated from 28
guage stainless steel must be mounted on the outlet of the pyramidal
section. A. 1.0 x 3.0 inch (25 x 76 mm) baffle plate of
0.18.002 inch (.50.05 mm) stainless steel must
be centered inside the stack, perpendicular to the air flow, 3 inches
(76 mm) above the base of the stack.
(6) Specimen Holders. (i) The specimen must be tested in a vertical
[[Page 6624]]
orientation. The specimen holder (Figure 3 of this part IV) must
incorporate a frame that touches the specimen (which is wrapped with
aluminum foil as required by paragraph (d)(3) of this Part) along only
the .25 inch (6 mm) perimeter. A ``V'' shaped spring is used to hold
the assembly together. A detachable .50 x .50 x 5.91 inch
(12 x 12 x 150 mm) drip pan and two .020 inch (.5 mm) stainless steel
wires (as shown in Figure 3 of this part IV) must be used for testing
materials prone to melting and dripping. The positioning of the spring
and frame may be changed to accommodate different specimen thicknesses
by inserting the retaining rod in different holes on the specimen
holder.
(ii) Since the radiation shield described in ASTM E-906 is not
used, a guide pin must be added to the injection mechanism. This fits
into a slotted metal plate on the injection mechanism outside of the
holding chamber. It can be used to provide accurate positioning of the
specimen face after injection. The front surface of the specimen must
be 3.9 inches (100 mm) from the closed radiation doors after injection.
(iii) The specimen holder clips onto the mounted bracket (Figure 3
of this part IV). The mounting bracket must be attached to the
injection rod by three screws that pass through a wide-area washer
welded onto a \1/2\-inch (13 mm) nut. The end of the injection rod must
be threaded to screw into the nut, and a .020 inch (5.1 mm) thick wide
area washer must be held between two \1/2\-inch (13 mm) nuts that are
adjusted to tightly cover the hole in the radiation doors through which
the injection rod or calibration calorimeter pass.
(7) * * *
(8) Pilot-Flame Positions. Pilot ignition of the specimen must be
accomplished by simultaneously exposing the specimen to a lower pilot
burner and an upper pilot burner, as described in paragraph (b)(8)(i)
and (b)(8)(ii) or (b)(8)(iii) of this part IV, respectively. Since
intermittent pilot flame extinguishment for more than 3 seconds would
invalidate the test results, a spark ignitor may be installed to ensure
that the lower pilot burner remains lighted.
(i) Lower Pilot Burner. The pilot-flame tubing must be .25 inch
(6.3 mm) O.D., .03 inch (0.8mm) wall, stainless steel tubing. A mixture
of 120 cm3/min. of methane and 850 cm3/min. of air must be
fed to the lower pilot flame burner. The normal position of the end of
the pilot burner tubing is .40 inch (10 mm) from and perpendicular to
the exposed vertical surface of the specimen. The centerline at the
outlet of the burner tubing must intersect the vertical centerline of
the sample at a point .20 inch (5 mm) above the lower exposed edge of
the specimen.
(ii) Standard Three-Hole Upper Burner. The pilot burner must be a
straight length of .25 inch (6.3 mm) O.D., .03 inch (0.8 mm) wall,
stainless steel tubing that is 14 inches (360 mm) long. One end of the
tubing must be closed, and three No. 40 drill holes must be drilled
into the tubing, 2.38 inch (60 mm) apart, for gas ports, all radiating
in the same direction. The first hole must be .19 inch (5 mm) from the
closed end of the tubing. The tube must be positioned .75 inch (19 mm)
above and .75 inch (19 mm) behind the exposed upper edge of the
specimen. The middle hole must be in the vertical plane perpendicular
to the exposed surface of the specimen which passes through its
vertical centerline and must be pointed toward the radiation source.
The gas supplied to the burner must be methane and must be adjusted to
produce flame lengths of 1 inch (25 mm).
(iii) Optional Fourteen-Hole Upper Pilot Burner. This burner may be
used in lieu of the standard three-hole burner described in paragraph
(b)(8)(ii) of this part IV. The pilot burner must be a straight length
of .25 inch (6.3 mm) O.D., .03 inch (0.8 mm) wall, stainless steel
tubing that is 15.75 inches (400 mm) long. One end of the tubing must
be closed, and 14 No. 59 drill holes must be drilled into the tubing,
.50 inch (13 mm) apart, for gas ports, all radiating in the same
direction. The first hole must be .50 inch (13 mm) from the closed end
of the tubing. The tube must be positioned above the specimen holder so
that the holes are placed above the specimen as shown in Figure 1B of
this part IV. The fuel supplied to the burner must be methane mixed
with air in a ratio of approximately 50/50 by volume. The total gas
flow must be adjusted to produce flame lengths of 1 inch (25 mm). When
the gas/air ratio and the flow rate are properly adjusted,
approximately .25 inch (6 mm) of the flame length appears yellow in
color.
(c) * * * (1) Heat Release Rate. A calibration burner, as shown in
Figure 4, must be placed over the end of the lower pilot flame tubing
using a gas tight connection. The flow of gas to the pilot flame must
be at least 99 percent methane and must be accurately metered. Prior to
usage, the wet test meter must be properly leveled and filled with
distilled water to the tip of the internal pointer while no gas is
flowing. Ambient temperature and pressure of the water are based on the
internal wet test meter temperature. A baseline flow rate of
approximately 1 liter/min. must be set and increased to higher preset
flows of 4, 6, 8, 6 and 4 liters/min. Immediately prior to recording
methane flow rates, a flow rate of 8 liters/min. must be used for 2
minutes to precondition the chamber. This is not recorded as part of
calibration. The rate must be determined by using a stopwatch to time a
complete revolution of the wet test meter for both the baseline and
higher flow, with the flow returned to baseline before changing to the
next higher flow. The thermopile baseline voltage must be measured. The
gas flow to the burner must be increased to the higher preset flow and
allowed to burn for 2.0 minutes, and the thermopile voltage must be
measured. The sequence must be repeated until all five values have been
determined. The average of the five values must be used as the
calibration factor. The procedure must be repeated if the percent
relative standard deviation is greater than 5 percent. Calculations are
shown in paragraph (f) of this part IV.
(2) * * *
(3) As noted in paragraph (b)(2) of this part IV, thermopile hot
junctions must be cleared of soot deposits as needed to maintain the
calibrated sensitivity.
(d) Preparation of Test Specimens. (1) The test specimens must be
representative of the aircraft component in regard to materials and
construction methods. The standard size for the test specimens is 5.91
.03 x 5.91 .03 inches (149 1
x 149 1 mm). The thickness of the specimen must be the
same as that of the aircraft component it represents up to a maximum
thickness of 1.75 inches (45 mm). Test specimens representing thicker
components must be 1.75 inches (45 mm).
(2) * * *
(3) Mounting. Each test specimen must be wrapped tightly on all
sides of the specimen, except for the one surface that is exposed with
a single layer of .001 inch (.025 mm) aluminum foil.
(e) Procedure. (1) The power supply to the radiant panel must be
set to produce a radiant flux of 3.5 .05 W/cm2, as
measured at the point the center of the specimen surface will occupy
when positioned for the test. The radiant flux must be measured after
the air flow through the equipment is adjusted to the desired rate.
(2) After the pilot flames are lighted, their position must be
checked as described in paragraph (b)(8) of this part IV.
(3) Air flow through the apparatus must be controlled by a circular
plate orifice located in a 1.5 inch (38.1 mm) I.D. pipe with two
pressure measuring
[[Page 6625]]
points, located 1.5 inches (38 mm) upstream and .75 inches (19 mm)
downstream of the orifice plate. The pipe must be connected to a
manometer set at a pressure differential of 7.87 inches (200 mm) of Hg.
(See Figure 1B of this part IV.) The total air flow to the equipment is
approximately .04 m3/seconds. The stop on the vertical specimen
holder rod must be adjusted so that the exposed surface of the specimen
is positioned 3.9 inches (100 mm) from the entrance when injected into
the environmental chamber.
(4) The specimen must be placed in the hold chamber with the
radiation doors closed. The airtight outer door must be secured, and
the recording devices must be started. The specimen must be retained in
the hold chamber for 60 seconds, plus or minus 10 seconds, before
injection. The thermopile ``zero'' value must be determined during the
last 20 seconds of the hold period. The sample must not be injected
before completion of the ``Zero'' value determination.
(5) When the specimen is to be injected, the radiation doors must
be opened. After the specimen is injected into the environmental
chamber, the radiation doors must be closed behind the specimen.
(6) * * *
(7) * * *
(8) The test duration is five minutes. The lower pilot burner and
the upper pilot burner must remain lighted for the entire duration of
the test, except that there may be intermittent flame extinguishment
for periods that do not exceed 3 seconds. Furthermore, if the optional
three-hole upper burner is used, at least two flamelets must remain
lighted for the entire duration of the test, except that there may be
intermittent flame extinguishment of all three flamelets for periods
that do not exceed 3 seconds.
(9) * * *
(f) * * *
(2) Heat release rates may be calculated from the reading of the
thermopile output voltage at any instant of time as:
[GRAPHIC][TIFF OMITTED]TR02FE95.006
HRR=heat release rate (kw/m\2\)
Vb=baseline voltage (mv)
Vm=measured thermopile voltage (mv)
Kh=calibration factor (kw/mv)
* * * * *
Figures to Part IV of Appendix F
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[[Page 6626]]
[GRAPHIC][TIFF OMITTED]TR02FE95.004
[[Page 6627]]
[GRAPHIC][TIFF OMITTED]TR02FE95.005
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[[Page 6628]]
* * * * *
PART 121--CERTIFICATION AND OPERATIONS: DOMESTIC, FLAG, AND
SUPPLEMENTAL AIR CARRIERS AND COMMERCIAL OPERATORS OF LARGE
AIRCRAFT
4. The authority citation for Part 121 continues to read as
follows:
Authority: 49 U.S.C. 1354(a), 1355, 1356, 1357, 1401, 1421-1430,
1472, 1485, and 1502; 49 U.S.C. 106(g); 49 CFR 1.47(a).
5. By amending Sec. 121.312 by revising paragraphs (a)(1) through
(a)(6), adding a new paragraph (a)(8), and revising paragraph (b) to
read as follows:
Sec. 121.312 Materials for compartment interiors.
(a) * * *
(1) Except as provided in paragraph (a)(6) of this section, each
airplane with a passenger capacity of 20 or more and manufactured after
August 19, 1988, but prior to August 20, 1990, must comply with the
heat release rate testing provisions of Sec. 25.853(d) in effect March
6, 1995 (formerly Sec. 25.853(a-1) in effect on August 20, 1986),
except that the total heat release over the first 2 minutes of sample
exposure must not exceed 100 kilowatt minutes per square meter and the
peak heat release rate must not exceed 100 kilowatts per square meter.
(2) Each airplane with a passenger capacity of 20 or more and
manufactured after August 19, 1990, must comply with the heat release
rate and smoke testing provisions of Sec. 25.853(d) in effect March 6,
1995 (formerly Sec. 25.853(a-1) in effect on September 26, 1988).
(3) Except as provided in paragraph (a)(5) or (a)(6) of this
section, each airplane for which the application for type certificate
was filed prior to May 1, 1972, must comply with the provisions of
Sec. 25.853 in effect on April 30, 1972, regardless of the passenger
capacity if there is a substantially complete replacement of the cabin
interior after April 30, 1972.
(4) Except as provided in paragraph (a)(5) or (a)(6) of this
section, each airplane for which the application for type certificate
was filed after May 1, 1972, must comply with the material requirements
under which the airplane was type certificated regardless of the
passenger capacity if there is a substantially complete replacement of
the cabin interior after that date.
(5) Except as provided in paragraph (a)(6) of this section, each
airplane that was type certificated after January 1, 1958, and has a
passenger capacity of 20 or more, must comply with the heat release
rate testing provisions of Sec. 25.853(d) in effect March 6, 1995
(formerly Sec. 25.853(a-1) in effect on August 20, 1986), if there is
substantially complete replacement of the cabin interior components
identified in Sec. 25.853(d) on or after that date, except that the
total heat release over the first 2 minutes of sample exposure shall
not exceed 100 killowatt-minutes per square meter and the peak heat
release rate shall not exceed 100 kilowatts per square meter.
(6) Each airplane that was type certificated after January 1, 1958,
and has a passenger capacity of 20 or more, must comply with the heat
release rate and smoke testing provisions of Sec. 25.853(d) in effect
March 6, 1995 (formerly Sec. 25.853(a-1) in effect on September 26,
1988), if there is a substantially complete replacement of the cabin
interior components identified in Sec. 25.853(d) on or after August 20,
1990.
* * * * *
(8) Contrary provisions of this section notwithstanding, galley
carts and galley standard containers that do not meet the flammability
and smoke emission requirements of Sec. 25.853(d) in effect March 6,
1995 (formerly Sec. 25.853(a-1)) may be used in airplanes that must
meet the requirements of paragraph (a-1), (a)(2), (a)(5) or (a)(6) of
this section, provided the galley carts or standard containers were
manufactured prior to March 6, 1995.
(b) For airplanes type certificated after January 1, 1958, seat
cushions, except those on flight crewmember seats, in any compartment
occupied by crew or passengers must comply with the requirements
pertaining to fire protection of seat cushions in Sec. 25.853(c)
effective on November 26, 1984.
PART 135--AIR TAXI OPERATORS AND COMMERCIAL OPERATORS
6. The authority citation for Part 135 continues to read as
follows:
Authority: 49 U.S.C. 1354(a), 1355(a), 1421-1431, and 1502; 49
U.S.C. 106(g); 49 CFR 1.47(a).
7. By amending Sec. 135.169 by revising paragraph (a) to read as
follows:
Sec. 135.169 Additional airworthiness requirements.
(a) Except for commuter category airplanes, no person may operate a
large airplane unless it meets the additional airworthiness
requirements of Secs. 121.213 through 121.283 and 121.307 of this
chapter.
* * * * *
8. By revising Sec. 135.170 to read as follows:
Sec. 135.170 Materials for compartment interiors.
(a) No person may operate an airplane that conforms to an amended
or supplemental type certificate issued in accordance with SFAR No. 41
for a maximum certificated takeoff weight in excess of 12,500 pounds
unless within one year after issuance of the initial airworthiness
certificate under that SFAR, the airplane meets the compartment
interior requirements set forth in Sec. 25.853(a) in effect March 6,
1995 (formerly Sec. 25.853 (a), (b), (b-1), (b-2), and (b-3) of this
chapter in effect on September 26, 1978).
(b) No person may operate a large airplane unless it meets the
following additional airworthiness requirements:
(1) Except for those materials covered by paragraph (b)(2) of this
section, all materials in each compartment used by the crewmembers or
passengers must meet the requirements of Sec. 25.853 of this chapter in
effect as follows or later amendment thereto:
(i) Except as provided in paragraph (b)(1)(iv) of this section,
each airplane with a passenger capacity of 20 or more and manufactured
after August 19, 1988, but prior to August 20, 1990, must comply with
the heat release rate testing provisions of Sec. 25.853(d) in effect
March 6, 1995 (formerly Sec. 25.853(a-1) in effect on August 20, 1986),
except that the total heat release over the first 2 minutes of sample
exposure rate must not exceed 100 kilowatt minutes per square meter and
the peak heat release rate must not exceed 100 kilowatts per square
meter.
(ii) Each airplane with a passenger capacity of 20 or more and
manufactured after August 19, 1990, must comply with the heat release
rate and smoke testing provisions of Sec. 25.853(d) in effect March 6,
1995 (formerly Sec. 25.83(a-1) in effect on September 26, 1988).
(iii) Except as provided in paragraph (b)(1) (v) or (vi) of this
section, each airplane for which the application for type certificate
was filed prior to May 1, 1972, must comply with the provisions of
Sec. 25.853 in effect on April 30, 1972, regardless of the passenger
capacity, if there is a substantially complete replacement of the cabin
interior after April 30, 1972.
(iv) Except as provided in paragraph (b)(1) (v) or (vi) of this
section, each airplane for which the application for type certificate
was filed after May 1, 1972, must comply with the material requirements
under which the airplane was type certificated regardless of the
passenger capacity if there is a substantially complete replacement of
the cabin interior after that date.
[[Page 6629]]
(v) Except as provided in paragraph (b)(1)(vi) of this section,
each airplane that was type certificated after January 1, 1958, must
comply with the heat release testing provisions of Sec. 25.853(d) in
effect March 6, 1995 (formerly Sec. 25.853(a-1) in effect on August 20,
1986), if there is a substantially complete replacement of the cabin
interior components identified in that paragraph on or after that date,
except that the total heat release over the first 2 minutes of sample
exposure shall not exceed 100 kilowatt-minutes per square meter and the
peak heat release rate shall not exceed 100 kilowatts per square meter.
(vi) Each airplane that was type certificated after January 1,
1958, must comply with the heat release rate and smoke testing
provisions of Sec. 25.853(d) in effect March 6, 1995 (formerly
Sec. 25.853(a-1) in effect on August 20, 1986), if there is a
substantially complete replacement of the cabin interior components
identified in that paragraph after August 19, 1990.
(vii) Contrary provisions of this section notwithstanding, the
Manager of the Transport Airplane Directorate, Aircraft Certification
Service, Federal Aviation Administration, may authorize deviation from
the requirements of paragraph (b)(1)(i), (b)(1)(ii), (b)(1)(v), or
(b)(1)(vi) of this section for specific components of the cabin
interior that do not meet applicable flammability and smoke emission
requirements, if the determination is made that special circumstances
exist that make compliance impractical. Such grants of deviation will
be limited to those airplanes manufactured within 1 year after the
applicable date specified in this section and those airplanes in which
the interior is replaced within 1 year of that date. A request for such
grant of deviation must include a thorough and accurate analysis of
each component subject to Sec. 25.853(d) in effect March 6, 1995
(formerly Sec. 25.853(a-1) in effect on August 20, 1986), the steps
being taken to achieve compliance, and for the few components for which
timely compliance will not be achieved, credible reasons for such
noncompliance.
(viii) Contrary provisions of this section notwithstanding, galley
carts and standard galley containers that do not meet the flammability
and smoke emission requirements of Sec. 25.853(d) in effect March 6,
1995 (formerly Sec. 25.853(a-1) in effect on August 20, 1986), may be
used in airplanes that must meet the requirements of paragraph
(b)(1)(i), (b)(1)(ii), (b)(1)(iv) or (b)(1)(vi) of this section
provided the galley carts or standard containers were manufactured
prior to March 6, 1995.
(2) For airplanes type certificated after January 1, 1958, seat
cushions, except those on flight crewmember seats, in any compartment
occupied by crew or passengers must comply with the requirements
pertaining to fire protection of seat cushions in Sec. 25.853(c)
effective November 26, 1984.
Issued in Washington, D.C., on January 24, 1995.
David R. Hinson,
Administrator.
[FR Doc. 95-2114 Filed 2-1-95; 8:45 am]
BILLING CODE 4910-13-M