[Federal Register: October 29, 2007 (Volume 72, Number 208)]
[Proposed Rules]
[Page 61085-61087]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr29oc07-18]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM383; Notice No. 25-07-15-SC]
Special Conditions: Boeing Model 777 Series Airplanes; Seats With
Non-Traditional, Large, Non-Metallic Panels
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed special conditions.
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SUMMARY: This action proposes special conditions for Boeing Model 777
series airplanes. These airplanes 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
proposed 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: We must receive your comments by November 28, 2007.
ADDRESSES: You must mail two copies of your comments to: Federal
Aviation Administration, Transport Airplane Directorate, Attn: Rules
Docket (ANM-113), Docket No. NM383, 1601 Lind Avenue, SW., Renton,
Washington 98057-3356. You may deliver two copies to the Transport
Airplane Directorate at the above address. You must mark your comments:
Docket No. NM383. You can inspect comments in the Rules Docket
weekdays, except Federal holidays, between 7:30 a.m. and 4 p.m.
FOR FURTHER INFORMATION CONTACT: Alan Sinclair, FAA, Airframe/Cabin
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 227-2195; facsimile (425) 227-1232; electronic
mail alan.sinclair@faa.gov.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite interested people to take part in this rulemaking by
sending written comments, data, or views. The most helpful comments
reference a specific portion of the special conditions, explain the
reason for any recommended change, and include supporting data. We ask
that you send us two copies of written comments.
We will file in the docket all comments we receive, as well as a
report summarizing each substantive public contact with FAA personnel
concerning these special conditions. You can inspect the docket before
and after the comment closing date. If you wish to review the docket in
person, go to the address in the ADDRESSES section of this preamble
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays.
We will consider all comments we receive on or before the closing
date for comments. We will consider comments filed late if it is
possible to do so without incurring expense or delay. We may change
these special conditions based on the comments we receive.
If you want the FAA to acknowledge receipt of your comments on this
proposal, include with your comments a pre-addressed, stamped postcard
on which the docket number appears. We will stamp the date on the
postcard and mail it back to you.
Proposed Change to Special Condition Number 4
The FAA previously notified the public of our intent to issue
special conditions for seats with non-traditional, large, non-metallic
panels on various airplane makes and models. Notice of Proposed Special
Conditions No. 25-06-13-SC, applicable to Boeing Model 737 series
airplanes, was published in the Federal Register on November 9, 2006
(71 FR 65761). The special conditions were issued on June 29, 2007
(Docket No. NM 359, Special Conditions No. 25-358-SC), published in the
Federal Register on July 10, 2007 (72 FR 37425), and became effective
on August 9, 2007. Both the Notice and the Final Special Conditions
contained these words:
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.
Special condition number 4 in the 737 special conditions limits the
applicability of the special conditions to new seat certification
programs applied for after the effective date of the special
conditions. In these proposed special conditions the FAA proposes to
change the applicability to make the special conditions applicable to
new seat certification programs that are approved after the effective
date of the special conditions. This change could affect pending as
well as future project applications. The rationale behind this proposed
change is that these seat installations affect survivability during a
post-crash fire event and should be implemented as soon as possible.
Additionally, the public has been previously notified of the FAA's
intent to issue similar special conditions on other airplane makes and
models.
Background
On August 8, 2005, Boeing Commercial Airplanes, P.O. Box 3707,
Seattle, Washington 98124, applied for a design change to Type
Certificate No. T00001SE for installation of seats that include non-
traditional, large, non-metallic panels in Boeing Model 777 series
airplanes. The Boeing Model 777 series airplanes, currently approved
under Type Certificate No. T00001SE, are swept-wing, conventional tail,
twin-engine, turbofan-powered, dual aisle, large-sized transport
category airplanes.
The applicable regulations to airplanes currently approved under
Type Certificate No. T00001SE 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 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
[[Page 61086]]
V, heat release and smoke emission requirements.
Type Certification Basis
Under the provisions of 14 CFR 21.101, Boeing must show that the
Model 777 series airplanes, as changed, continue to meet the applicable
provisions of the regulations incorporated by reference in Type
Certificate No. T00001SE, 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. T00001SE are as follows:
For Model 777-200 airplanes--Title 14 CFR part 25, as
amended by Amendment 25-1 through Amendment 25-82.
For Model 777-200LR airplanes--Title 14 CFR part 25, as
amended by Amendment 25-1 through Amendment 25-100 with the exceptions
listed: Sec. Sec. 25.831(a) and 25.831(g) at Amendment 25-86; Sec.
25.841(a) at Amendment 25-86; and Sec. 25.853(d)(3) at Amendment 25-
82.
For Model 777-300 airplanes--Title 14 CFR part 25, as
amended by Amendment 25-1 through Amendment 25-86 with the exception
listed: Sec. 25.853(d)(3), Compartment interiors, at Amendment 25-82.
For Model 777-300ER airplanes--Title 14 CFR part 25, as
amended by Amendment 25-1 through Amendment 25-98 with the exception
listed: Sec. 25.853(d)(3), Compartment interiors, at Amendment 25-82.
In addition, the certification basis includes certain special
conditions, exemptions, or later amended sections of the applicable
part that are not relevant to these proposed special conditions.
If the Administrator finds that the applicable airworthiness
regulations (i.e., 14 CFR part 25) do not contain adequate or
appropriate safety standards for the Boeing Model 777 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 777 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.
Special conditions, as defined in Sec. 11.19, are issued in
accordance with Sec. 11.38 and become part of the type certification
basis in accordance with Sec. 21.101.
Special conditions are initially applicable to the model for which
they are issued. Should the type certificate for that model be amended
later to include any other model that incorporates the same or similar
novel or unusual design feature, or should any other model already
included on the same type certificate be modified 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 777 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.
Definition of ``Non-Traditional, Large, Non-Metallic Panel''
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 61087]]
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 (http://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 14 CFR 25.853(d) to seats with large, non-metallic
panels in their design.
Applicability
As discussed above, these special conditions are applicable to
Boeing Model 777 series airplanes. Because the heat release and smoke
testing requirements of Sec. 25.853 are part of the type certification
basis for the Model 777, these special conditions are applicable to all
new seat certification programs for Model 777 series airplanes. The
existing (i.e., with unchanged interiors) Model 777 fleet and follow-on
deliveries of Model 777 series airplanes with previously certificated
interiors are not affected. Should Boeing apply at a later date for a
change to the type certificate to include another model incorporating
the same novel or unusual design feature, the special conditions would
apply to that model as well.
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.
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 Proposed Special Conditions
Accordingly, the Federal Aviation Administration (FAA) proposes the
following special conditions as part of the type certification basis
for Boeing Model 777 series airplanes.
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.
4. Only airplanes associated with new seat certification programs
approved after the effective date of these special conditions will be
affected by the requirements in these special conditions. Previously
certificated interiors on the existing airplane fleet and follow-on
deliveries of airplanes with previously certificated interiors are not
affected.
Issued in Renton, Washington, on October 19, 2007.
Ali Bahrami
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E7-21248 Filed 10-26-07; 8:45 am]
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