Special Conditions: Boeing Model 757 Series Airplanes; Seats With Non-Traditional, Large, Non-Metallic Panels, 73585-73587 [E7-25077]
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Federal Register / Vol. 72, No. 248 / Friday, December 28, 2007 / Rules and Regulations
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remove any dispute about how to assess
the severity and likelihood of
occurrence of a threat over which the
applicant has no control.
FAA Response: We agree that a
‘‘security threat analysis process’’ (or
other acceptable means) should be
conducted to determine the threats,
vulnerabilities, and risks of each
airplane network access from an
external source to determine
appropriate security mitigation
protection and procedures for the
aircraft, its operations, and
maintenance. The aircraft and system
safety assessments (as described in AC
25.1309) should certainly consider the
impact of security vulnerabilities on
aircraft safety and the capabilities of the
aircraft’s systems to satisfy reliability
and integrity requirements. Detailed
guidelines and criteria, specific to the
787 network architecture and design,
have been developed for this aircraft
and provide some initial guidance for an
acceptable means of compliance. The
FAA also intends to participate in
industry efforts to develop additional
guidance on the scope of security
assessments and a general means of
addressing aircraft network security
concerns. We hope to endorse the
industry-developed guidance, when it
has been completed, with an advisory
circular. We have made some minor
changes to these special conditions as a
result of this comment to clarify the
scope for security threat analysis.
• AIRBUS proposed text revision:
Airbus proposed the following revised
wording for these special conditions.
The applicant shall ensure that
security threats external to the aircraft
(including those possibly caused by
maintenance activity) are assessed and
risk mitigation strategies are
implemented to protect the Aircraft
Control Domain and Airline Information
Services Domain from adverse impacts
reducing the aircraft safety.
FAA Response: Airbus’s comments
and proposal have merit but the
proposal does not address all of the
FAA concerns. We have, however,
adopted several aspects of the
commenter’s proposal into these final
special conditions. We have made these
wording changes for clarification, but
the meaning and intent of these special
conditions remain the same as originally
proposed.
Applicability
As discussed above, these special
conditions are applicable to the 787.
Should Boeing apply at a later date for
a change to the type certificate to
include another model on the same type
certificate incorporating the same novel
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or unusual design features, these special
conditions would apply to that model as
well.
Conclusion
This action affects only certain novel
or unusual design features of the 787. It
is not a rule of general applicability.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting
and recordkeeping requirements.
The authority citation for these
special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701,
44702, 44704.
The Special Conditions
Accordingly, pursuant to the
authority delegated to me by the
Administrator, the following special
conditions are issued as part of the type
certification basis for the Boeing Model
787–8 airplane.
The applicant shall ensure system security
protection for the Aircraft Control Domain
and Airline Information Domain from access
by unauthorized sources external to the
airplane, including those possibly caused by
maintenance activity. The applicant shall
ensure that security threats are identified and
assessed, and that risk mitigation strategies
are implemented to protect the airplane from
all adverse impacts on safety, functionality,
and continued airworthiness.
Issued in Renton, Washington, on
December 17, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate,
Aircraft Certification Service.
[FR Doc. E7–25075 Filed 12–27–07; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM385; Special Conditions No.
25–364–SC]
Special Conditions: Boeing Model 757
Series Airplanes; Seats With NonTraditional, Large, Non-Metallic Panels
Federal Aviation
Administration (FAA), DOT.
ACTION: Final special conditions.
AGENCY:
SUMMARY: These special conditions are
issued for Boeing Model 757 Series
Airplanes. These airplanes, as modified
by Triad International Maintenance
Company (TIMCO), will have a novel or
unusual design feature(s) associated
with seats that include non-traditional,
large, non-metallic panels that would
affect survivability during a post-crash
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73585
fire event. The applicable airworthiness
regulations do not contain adequate or
appropriate safety standards for this
design feature. These special conditions
contain the additional safety standards
that the Administrator considers
necessary to establish a level of safety
equivalent to that established by the
existing airworthiness standards.
DATES: Effective Date: The effective date
of these special conditions is December
18, 2007.
FOR FURTHER INFORMATION CONTACT: Dan
Jacquet, FAA, Airframe/Cabin Safety
Branch, ANM–115, Transport Airplane
Directorate, Aircraft Certification
Service, 1601 Lind Avenue, SW.,
Renton, Washington, 98057–3356;
telephone (425) 227–2676; facsimile
(425) 227–1232; electronic mail
daniel.jacquet@faa.gov.
SUPPLEMENTARY INFORMATION:
Future Requests for Installation of Seats
with Non-Traditional, Large, NonMetallic Panels
We anticipate that seats with nontraditional, large, non-metallic panels
will be installed in other makes and
models of airplanes. We have made the
determination to require special
conditions for all applications
requesting the installation of seats with
non-traditional, large, non-metallic
panels until the airworthiness
requirements can be revised to address
this issue. Having the same standards
across the range of airplane makes and
models will ensure a level playing field
for the aviation industry.
Background
On July 31, 2007, Triad International
Maintenance Company (TIMCO), 623
Radar Road, Greensboro, North Carolina
27410, applied for a supplemental type
certificate for installing seats that
include non-traditional, large, nonmetallic panels in a Boeing Model 757
series airplane. The Boeing Model 757
series airplanes, currently approved
under Type Certificate No. A2NM, are
swept-wing, conventional tail, twinengine, turbofan-powered, single aisle,
medium-sized transport category
airplanes.
The applicable regulations to
airplanes currently approved under
Type Certificate No. A2NM do not
require seats to meet the more stringent
flammability standards required of
large, non-metallic panels in the cabin
interior. At the time the applicable rules
were written, seats were designed with
a metal frame covered by fabric, not
with large, non-metallic panels. Seats
also met the then recently adopted
standards for flammability of seat
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cushions. With the seat design being
mostly fabric and metal, the
contribution to a fire in the cabin had
been minimized and was not considered
a threat. For these reasons, seats did not
need to be tested to heat release and
smoke emission requirements.
Seat designs have now evolved to
occasionally include non-traditional,
large, non-metallic panels. Taken in
total, the surface area of these panels is
on the same order as the sidewall and
overhead stowage bin interior panels.
To provide the level of passenger
protection intended by the
airworthiness standards, these nontraditional, large, non-metallic panels in
the cabin must meet the standards of
Title 14 Code of Federal Regulations
(CFR), part 25, Appendix F, parts IV and
V, heat release and smoke emission
requirements.
Type Certification Basis
Under the provisions of 14 CFR
21.101, TIMCO must show that the
Boeing Model 757 series airplanes, as
changed, continue to meet the
applicable provisions of the regulations
incorporated by reference in Type
Certificate No. A2NM, or the applicable
regulations in effect on the date of
application for the change. The
regulations incorporated by reference in
the type certificate are commonly
referred to as the ‘‘original type
certification basis.’’ The regulations
incorporated by reference in Type
Certificate No. A2NM are as follows:
• For Model 757–200 airplanes—part
25, as amended by Amendment 25–1
through Amendment 25–45. In addition,
an equivalent safety finding exists with
respect to § 25.853(c), Compartment
interiors.
• For Model 757–300 airplanes—part
25, as amended by Amendment 25–1
through Amendment 25–85 with the
exception listed: Section 25.853(d)(3),
Compartment interiors, at Amendment
25–72.
In addition, the certification basis
includes certain special conditions,
exemptions, or later amended sections
of the applicable part that are not
relevant to these special conditions.
If the Administrator finds that the
applicable airworthiness regulations
(i.e., part 25) do not contain adequate or
appropriate safety standards for the
Boeing Model 757 series airplanes
because of a novel or unusual design
feature, special conditions are
prescribed under the provisions of
§ 21.16.
In addition to the applicable
airworthiness regulations and special
conditions, the Boeing Model 757 series
airplanes must comply with the fuel
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Jkt 214001
vent and exhaust emission requirements
of 14 CFR part 34 and the noise
certification requirements of 14 CFR
part 36.
The FAA issues special conditions, as
defined in § 11.19, under § 11.38 and
they become part of the type
certification basis under § 21.101.
Special conditions are initially
applicable to the model for which they
are issued. Should the applicant apply
for a supplemental type certificate to
modify any other model included on the
same type certificate to incorporate the
same or similar novel or unusual design
feature, the special conditions would
also apply to the other model under
§ 21.101.
Novel or Unusual Design Features
The Boeing Model 757 series
airplanes will incorporate the following
novel or unusual design features: These
models offer interior arrangements that
include passenger seats that incorporate
non-traditional, large, non-metallic
panels in lieu of the traditional metal
frame covered by fabric. The
flammability properties of these panels
have been shown to significantly affect
the survivability of the cabin in the case
of fire. These seats are considered a
novel design for transport category
airplanes that include Amendment 25–
61 and Amendment 25–66 in the
certification basis, and were not
considered when those airworthiness
standards were established.
The existing regulations do not
provide adequate or appropriate safety
standards for seat designs that
incorporate non-traditional, large, nonmetallic panels in their designs. In order
to provide a level of safety that is
equivalent to that afforded to the
balance of the cabin, additional
airworthiness standards, in the form of
special conditions, are necessary. These
special conditions supplement § 25.853.
The requirements contained in these
special conditions consist of applying
the identical test conditions required of
all other large panels in the cabin, to
seats with non-traditional, large, nonmetallic panels.
A non-traditional, large, non-metallic
panel, in this case, is defined as a panel
with exposed-surface areas greater than
1.5 square feet installed per seat place.
The panel may consist of either a single
component or multiple components in a
concentrated area. Examples of parts of
the seat where these non-traditional
panels are installed include, but are not
limited to: seat backs, bottoms and leg/
foot rests, kick panels, back shells,
credenzas and associated furniture.
Examples of traditional exempted parts
of the seat include: arm caps, armrest
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Sfmt 4700
close-outs such as end bays and armreststyled center consoles, food trays, video
monitors, and shrouds.
Clarification of ‘‘Exposed’’
‘‘Exposed’’ is considered to include
panels that are directly exposed to the
passenger cabin in the traditional sense,
and panels that are enveloped, such as
by a dress cover. Traditional fabrics or
leathers currently used on seats are
excluded from these special conditions.
These materials must still comply with
§ 25.853(a) and § 25.853(c) if used as a
covering for a seat cushion, or
§ 25.853(a) if installed elsewhere on the
seat. Non-traditional, large, non-metallic
panels covered with traditional fabrics
or leathers will be tested without their
coverings or covering attachments.
Discussion
In the early 1980s the FAA conducted
extensive research on the effects of postcrash flammability in the passenger
cabin. As a result of this research and
service experience, we adopted new
standards for interior surfaces
associated with large surface area parts.
Specifically, the rules require
measurement of heat release and smoke
emission (part 25, Appendix F, parts IV
and V) for the affected parts. Heat
release has been shown to have a direct
correlation with post-crash fire survival
time. Materials that comply with the
standards (i.e., § 25.853 entitled
‘‘Compartment interiors’’ as amended by
Amendment 25–61 and Amendment
25–66) extend survival time by
approximately 2 minutes over materials
that do not comply.
At the time these standards were
written the potential application of the
requirements of heat release and smoke
emission to seats was explored. The seat
frame itself was not a concern because
it was primarily made of aluminum and
there were only small amounts of nonmetallic materials. It was determined
that the overall effect on survivability
was negligible, whether or not the food
trays met the heat release and smoke
requirements. The requirements
therefore did not address seats. The
preambles to both the Notice of
Proposed Rule Making (NPRM), Notice
No. 85–10 (50 FR 15038, April 16, 1985)
and the Final Rule at Amendment 25–
61 (51 FR 26206, July 21, 1986),
specifically note that seats were
excluded ‘‘because the recently-adopted
standards for flammability of seat
cushions will greatly inhibit
involvement of the seats.’’
Subsequently, the Final Rule at
Amendment 25–83 (60 FR 6615, March
6, 1995) clarified the definition of
minimum panel size: ‘‘It is not possible
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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.’’
In the late 1990s, the FAA issued
Policy Memorandum 97–112–39,
Guidance for Flammability Testing of
Seat/Console Installations, October 17,
1997 (https://rgl.faa.gov). That memo
was issued when it became clear that
seat designs were evolving to include
large, non-metallic panels with surface
areas that would impact survivability
during a cabin fire event, comparable to
partitions or galleys. The memo noted
that large surface area panels must
comply with heat release and smoke
emission requirements, even if they
were attached to a seat. If the FAA had
not issued such policy, seat designs
could have been viewed as a loophole
to the airworthiness standards that
would result in an unacceptable
decrease in survivability during a cabin
fire event.
In October of 2004, an issue was
raised regarding the appropriate
flammability standards for passenger
seats that incorporated non-traditional,
large, non-metallic panels in lieu of the
traditional metal covered by fabric. The
Seattle Aircraft Certification Office and
Transport Standards Staff reviewed this
design and determined that it
represented the kind and quantity of
material that should be required to pass
the heat release and smoke emissions
requirements. We have determined that
special conditions would be
promulgated to apply the standards
defined in § 25.853(d) to seats with
large, non-metallic panels in their
design.
Discussion of Comments
Notice of proposed special conditions
No. 25–07–17-SC, pertaining to Boeing
Model 757 series airplanes, was
published in the Federal Register on
November 27, 2007. No comments were
received and the special conditions are
adopted as proposed.
Applicability
As discussed above, these special
conditions are applicable to Boeing
Model 757 series airplanes. It is not our
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23:53 Dec 27, 2007
Jkt 214001
intent, however, to require seats with
large, non-metallic panels to meet
§ 25.853, Appendix F, parts IV and V, if
they are installed in cabins of airplanes
that otherwise are not required to meet
these standards. Because the heat
release and smoke testing requirements
of § 25.853 per Appendix F, parts IV and
V, are not part of the type certification
basis of the Model 757, these special
conditions are only applicable if the
Model 757 series airplanes are in 14
CFR part 121 operations. Section
121.312 requires compliance with the
heat release and smoke testing
requirements of § 25.853, for certain
airplanes, irrespective of the type
certification bases of those airplanes.
For Model 757 series airplanes, these
are the airplanes that would be affected
by these special conditions. Should
TIMCO apply at a later date for a
supplemental type certificate to modify
any other model included on Type
Certificate No. A2NM to incorporate the
same novel or unusual design feature,
the special conditions would apply to
that model as well.
Effective Upon Issuance
Under standard practice, the effective
date of final special conditions would
be 30 days after the date of publication
in the Federal Register; however, as the
delivery date for the Boeing Model 757
series airplane modified by TIMCO is
imminent, the FAA finds that good
cause exists to make these special
conditions effective upon issuance.
Conclusion
This action affects only certain novel
or unusual design features on one model
series of airplanes. It is not a rule of
general applicability and it affects only
the applicant who applied to the FAA
for approval of these features on the
airplane.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting
and recordkeeping requirements.
The authority citation for these
special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701,
44702, 44704.
The Special Conditions
Accordingly, pursuant to the
authority delegated to me by the
Administrator, the following special
conditions are issued as part of the type
certification basis for Boeing Model 757
series airplanes modified by TIMCO.
1. Except as provided in paragraph 3
of these special conditions, compliance
with Title 14 CFR part 25, Appendix F,
parts IV and V, heat release and smoke
emission, is required for seats that
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73587
incorporate non-traditional, large, nonmetallic panels that may either be a
single component or multiple
components in a concentrated area in
their design.
2. The applicant may designate up to
and including 1.5 square feet of nontraditional, non-metallic panel material
per seat place that does not have to
comply with special condition Number
1, above. A triple seat assembly may
have a total of 4.5 square feet excluded
on any portion of the assembly (e.g.,
outboard seat place 1 square foot,
middle 1 square foot, and inboard 2.5
square feet).
3. Seats do not have to meet the test
requirements of Title 14 CFR part 25,
Appendix F, parts IV and V, when
installed in compartments that are not
otherwise required to meet these
requirements. Examples include:
a. Airplanes with passenger capacities
of 19 or less,
b. Airplanes that do not have § 25.853,
Amendment 25–61 or later, in their
certification basis and do not need to
comply with the requirements of 14 CFR
121.312, and
c. Airplanes exempted from § 25.853,
Amendment 25–61 or later.
Issued in Renton, Washington, on
December 18, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate,
Aircraft Certification Service.
[FR Doc. E7–25077 Filed 12–27–07; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2007–28352; Directorate
Identifier 2007–NM–037–AD; Amendment
39–15309; AD 2007–26–07]
RIN 2120–AA64
Airworthiness Directives; Boeing
Model 747–200B, 747–300, 747–400,
747–400D, and 747–400F Series
Airplanes Equipped with General
Electric CF6–80C2 Engines
Federal Aviation
Administration (FAA), Department of
Transportation (DOT).
ACTION: Final rule.
AGENCY:
SUMMARY: The FAA is adopting a new
airworthiness directive (AD) for certain
Boeing Model 747–200B, 747–300, 747–
400, 747–400D, and 747–400F series
airplanes. This AD requires repetitive
inspections of the left- and right-hand
flipper door assemblies of the engine
E:\FR\FM\28DER1.SGM
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]]>Agencies
[Federal Register Volume 72, Number 248 (Friday, December 28, 2007)]
[Rules and Regulations]
[Pages 73585-73587]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E7-25077]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM385; Special Conditions No. 25-364-SC]
Special Conditions: Boeing Model 757 Series Airplanes; Seats With
Non-Traditional, Large, Non-Metallic Panels
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions.
-----------------------------------------------------------------------
SUMMARY: These special conditions are issued for Boeing Model 757
Series Airplanes. These airplanes, as modified by Triad International
Maintenance Company (TIMCO), will have a novel or unusual design
feature(s) associated with seats that include non-traditional, large,
non-metallic panels that would affect survivability during a post-crash
fire event. The applicable airworthiness regulations do not contain
adequate or appropriate safety standards for this design feature. These
special conditions contain the additional safety standards that the
Administrator considers necessary to establish a level of safety
equivalent to that established by the existing airworthiness standards.
DATES: Effective Date: The effective date of these special conditions
is December 18, 2007.
FOR FURTHER INFORMATION CONTACT: Dan Jacquet, FAA, Airframe/Cabin
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue, SW., Renton, Washington,
98057-3356; telephone (425) 227-2676; facsimile (425) 227-1232;
electronic mail daniel.jacquet@faa.gov.
SUPPLEMENTARY INFORMATION:
Future Requests for Installation of Seats with Non-Traditional, Large,
Non-Metallic Panels
We anticipate that seats with non-traditional, large, non-metallic
panels will be installed in other makes and models of airplanes. We
have made the determination to require special conditions for all
applications requesting the installation of seats with non-traditional,
large, non-metallic panels until the airworthiness requirements can be
revised to address this issue. Having the same standards across the
range of airplane makes and models will ensure a level playing field
for the aviation industry.
Background
On July 31, 2007, Triad International Maintenance Company (TIMCO),
623 Radar Road, Greensboro, North Carolina 27410, applied for a
supplemental type certificate for installing seats that include non-
traditional, large, non-metallic panels in a Boeing Model 757 series
airplane. The Boeing Model 757 series airplanes, currently approved
under Type Certificate No. A2NM, are swept-wing, conventional tail,
twin-engine, turbofan-powered, single aisle, medium-sized transport
category airplanes.
The applicable regulations to airplanes currently approved under
Type Certificate No. A2NM do not require seats to meet the more
stringent flammability standards required of large, non-metallic panels
in the cabin interior. At the time the applicable rules were written,
seats were designed with a metal frame covered by fabric, not with
large, non-metallic panels. Seats also met the then recently adopted
standards for flammability of seat
[[Page 73586]]
cushions. With the seat design being mostly fabric and metal, the
contribution to a fire in the cabin had been minimized and was not
considered a threat. For these reasons, seats did not need to be tested
to heat release and smoke emission requirements.
Seat designs have now evolved to occasionally include non-
traditional, large, non-metallic panels. Taken in total, the surface
area of these panels is on the same order as the sidewall and overhead
stowage bin interior panels. To provide the level of passenger
protection intended by the airworthiness standards, these non-
traditional, large, non-metallic panels in the cabin must meet the
standards of Title 14 Code of Federal Regulations (CFR), part 25,
Appendix F, parts IV and V, heat release and smoke emission
requirements.
Type Certification Basis
Under the provisions of 14 CFR 21.101, TIMCO must show that the
Boeing Model 757 series airplanes, as changed, continue to meet the
applicable provisions of the regulations incorporated by reference in
Type Certificate No. A2NM, or the applicable regulations in effect on
the date of application for the change. The regulations incorporated by
reference in the type certificate are commonly referred to as the
``original type certification basis.'' The regulations incorporated by
reference in Type Certificate No. A2NM are as follows:
For Model 757-200 airplanes--part 25, as amended by
Amendment 25-1 through Amendment 25-45. In addition, an equivalent
safety finding exists with respect to Sec. 25.853(c), Compartment
interiors.
For Model 757-300 airplanes--part 25, as amended by
Amendment 25-1 through Amendment 25-85 with the exception listed:
Section 25.853(d)(3), Compartment interiors, at Amendment 25-72.
In addition, the certification basis includes certain special
conditions, exemptions, or later amended sections of the applicable
part that are not relevant to these special conditions.
If the Administrator finds that the applicable airworthiness
regulations (i.e., part 25) do not contain adequate or appropriate
safety standards for the Boeing Model 757 series airplanes because of a
novel or unusual design feature, special conditions are prescribed
under the provisions of Sec. 21.16.
In addition to the applicable airworthiness regulations and special
conditions, the Boeing Model 757 series airplanes must comply with the
fuel vent and exhaust emission requirements of 14 CFR part 34 and the
noise certification requirements of 14 CFR part 36.
The FAA issues special conditions, as defined in Sec. 11.19, under
Sec. 11.38 and they become part of the type certification basis under
Sec. 21.101.
Special conditions are initially applicable to the model for which
they are issued. Should the applicant apply for a supplemental type
certificate to modify any other model included on the same type
certificate to incorporate the same or similar novel or unusual design
feature, the special conditions would also apply to the other model
under Sec. 21.101.
Novel or Unusual Design Features
The Boeing Model 757 series airplanes will incorporate the
following novel or unusual design features: These models offer interior
arrangements that include passenger seats that incorporate non-
traditional, large, non-metallic panels in lieu of the traditional
metal frame covered by fabric. The flammability properties of these
panels have been shown to significantly affect the survivability of the
cabin in the case of fire. These seats are considered a novel design
for transport category airplanes that include Amendment 25-61 and
Amendment 25-66 in the certification basis, and were not considered
when those airworthiness standards were established.
The existing regulations do not provide adequate or appropriate
safety standards for seat designs that incorporate non-traditional,
large, non-metallic panels in their designs. In order to provide a
level of safety that is equivalent to that afforded to the balance of
the cabin, additional airworthiness standards, in the form of special
conditions, are necessary. These special conditions supplement Sec.
25.853. The requirements contained in these special conditions consist
of applying the identical test conditions required of all other large
panels in the cabin, to seats with non-traditional, large, non-metallic
panels.
A non-traditional, large, non-metallic panel, in this case, is
defined as a panel with exposed-surface areas greater than 1.5 square
feet installed per seat place. The panel may consist of either a single
component or multiple components in a concentrated area. Examples of
parts of the seat where these non-traditional panels are installed
include, but are not limited to: seat backs, bottoms and leg/foot
rests, kick panels, back shells, credenzas and associated furniture.
Examples of traditional exempted parts of the seat include: arm caps,
armrest close-outs such as end bays and armrest-styled center consoles,
food trays, video monitors, and shrouds.
Clarification of ``Exposed''
``Exposed'' is considered to include panels that are directly
exposed to the passenger cabin in the traditional sense, and panels
that are enveloped, such as by a dress cover. Traditional fabrics or
leathers currently used on seats are excluded from these special
conditions. These materials must still comply with Sec. 25.853(a) and
Sec. 25.853(c) if used as a covering for a seat cushion, or Sec.
25.853(a) if installed elsewhere on the seat. Non-traditional, large,
non-metallic panels covered with traditional fabrics or leathers will
be tested without their coverings or covering attachments.
Discussion
In the early 1980s the FAA conducted extensive research on the
effects of post-crash flammability in the passenger cabin. As a result
of this research and service experience, we adopted new standards for
interior surfaces associated with large surface area parts.
Specifically, the rules require measurement of heat release and smoke
emission (part 25, Appendix F, parts IV and V) for the affected parts.
Heat release has been shown to have a direct correlation with post-
crash fire survival time. Materials that comply with the standards
(i.e., Sec. 25.853 entitled ``Compartment interiors'' as amended by
Amendment 25-61 and Amendment 25-66) extend survival time by
approximately 2 minutes over materials that do not comply.
At the time these standards were written the potential application
of the requirements of heat release and smoke emission to seats was
explored. The seat frame itself was not a concern because it was
primarily made of aluminum and there were only small amounts of non-
metallic materials. It was determined that the overall effect on
survivability was negligible, whether or not the food trays met the
heat release and smoke requirements. The requirements therefore did not
address seats. The preambles to both the Notice of Proposed Rule Making
(NPRM), Notice No. 85-10 (50 FR 15038, April 16, 1985) and the Final
Rule at Amendment 25-61 (51 FR 26206, July 21, 1986), specifically note
that seats were excluded ``because the recently-adopted standards for
flammability of seat cushions will greatly inhibit involvement of the
seats.''
Subsequently, the Final Rule at Amendment 25-83 (60 FR 6615, March
6, 1995) clarified the definition of minimum panel size: ``It is not
possible
[[Page 73587]]
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.''
In the late 1990s, the FAA issued Policy Memorandum 97-112-39,
Guidance for Flammability Testing of Seat/Console Installations,
October 17, 1997 (https://rgl.faa.gov). That memo was issued when it
became clear that seat designs were evolving to include large, non-
metallic panels with surface areas that would impact survivability
during a cabin fire event, comparable to partitions or galleys. The
memo noted that large surface area panels must comply with heat release
and smoke emission requirements, even if they were attached to a seat.
If the FAA had not issued such policy, seat designs could have been
viewed as a loophole to the airworthiness standards that would result
in an unacceptable decrease in survivability during a cabin fire event.
In October of 2004, an issue was raised regarding the appropriate
flammability standards for passenger seats that incorporated non-
traditional, large, non-metallic panels in lieu of the traditional
metal covered by fabric. The Seattle Aircraft Certification Office and
Transport Standards Staff reviewed this design and determined that it
represented the kind and quantity of material that should be required
to pass the heat release and smoke emissions requirements. We have
determined that special conditions would be promulgated to apply the
standards defined in Sec. 25.853(d) to seats with large, non-metallic
panels in their design.
Discussion of Comments
Notice of proposed special conditions No. 25-07-17-SC, pertaining
to Boeing Model 757 series airplanes, was published in the Federal
Register on November 27, 2007. No comments were received and the
special conditions are adopted as proposed.
Applicability
As discussed above, these special conditions are applicable to
Boeing Model 757 series airplanes. It is not our intent, however, to
require seats with large, non-metallic panels to meet Sec. 25.853,
Appendix F, parts IV and V, if they are installed in cabins of
airplanes that otherwise are not required to meet these standards.
Because the heat release and smoke testing requirements of Sec. 25.853
per Appendix F, parts IV and V, are not part of the type certification
basis of the Model 757, these special conditions are only applicable if
the Model 757 series airplanes are in 14 CFR part 121 operations.
Section 121.312 requires compliance with the heat release and smoke
testing requirements of Sec. 25.853, for certain airplanes,
irrespective of the type certification bases of those airplanes. For
Model 757 series airplanes, these are the airplanes that would be
affected by these special conditions. Should TIMCO apply at a later
date for a supplemental type certificate to modify any other model
included on Type Certificate No. A2NM to incorporate the same novel or
unusual design feature, the special conditions would apply to that
model as well.
Effective Upon Issuance
Under standard practice, the effective date of final special
conditions would be 30 days after the date of publication in the
Federal Register; however, as the delivery date for the Boeing Model
757 series airplane modified by TIMCO is imminent, the FAA finds that
good cause exists to make these special conditions effective upon
issuance.
Conclusion
This action affects only certain novel or unusual design features
on one model series of airplanes. It is not a rule of general
applicability and it affects only the applicant who applied to the FAA
for approval of these features on the airplane.
List of Subjects in 14 CFR Part 25
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.
The Special Conditions
Accordingly, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the type certification basis for Boeing Model 757 series airplanes
modified by TIMCO.
1. Except as provided in paragraph 3 of these special conditions,
compliance with Title 14 CFR part 25, Appendix F, parts IV and V, heat
release and smoke emission, is required for seats that incorporate non-
traditional, large, non-metallic panels that may either be a single
component or multiple components in a concentrated area in their
design.
2. The applicant may designate up to and including 1.5 square feet
of non-traditional, non-metallic panel material per seat place that
does not have to comply with special condition Number 1, above. A
triple seat assembly may have a total of 4.5 square feet excluded on
any portion of the assembly (e.g., outboard seat place 1 square foot,
middle 1 square foot, and inboard 2.5 square feet).
3. Seats do not have to meet the test requirements of Title 14 CFR
part 25, Appendix F, parts IV and V, when installed in compartments
that are not otherwise required to meet these requirements. Examples
include:
a. Airplanes with passenger capacities of 19 or less,
b. Airplanes that do not have Sec. 25.853, Amendment 25-61 or
later, in their certification basis and do not need to comply with the
requirements of 14 CFR 121.312, and
c. Airplanes exempted from Sec. 25.853, Amendment 25-61 or later.
Issued in Renton, Washington, on December 18, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-25077 Filed 12-27-07; 8:45 am]
BILLING CODE 4910-13-P
