Special Conditions: Boeing Model 757 Series Airplanes; Seats with Non-Traditional, Large, Non-Metallic Panels, 23612-23614 [E9-11723]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 74, Number 96 (Wednesday, May 20, 2009)]
[Rules and Regulations]
[Pages 23612-23614]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E9-11723]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM404; Special Conditions No. 25-382-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; request for comments.

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SUMMARY: These special conditions are issued for Boeing Model 757 
series airplanes. These airplanes, as modified by Northwest Airspace 
Technologies, Inc., will have a novel or unusual design feature 
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: The effective date of these special conditions is May 11, 2009. 
We must receive your comments by July 6, 2009.

ADDRESSES: You must mail two copies of your comments to: Federal 
Aviation Administration, Transport Airplane Directorate, Attn: Rules 
Docket (ANM-113), Docket No. NM404, 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. NM404. 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: John Shelden, FAA, Airframe/Cabin 
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue, SW., Renton, Washington 98057-
3356; telephone (425) 227-2785; facsimile (425) 227-1232.

SUPPLEMENTARY INFORMATION:

Future Requests for Installation of Seats With Non-Traditional, Large, 
Non-Metallic Panels

    The FAA has determined that notice of, and opportunity for prior 
public comment on, these special conditions are impracticable because 
these procedures would significantly delay issuance of the design 
approval and thus return to service of the affected aircraft. The FAA 
therefore finds that good cause exists for making these special 
conditions effective upon issuance.
    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 consistent ruling for 
the aviation industry.

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 
about 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 7:30 a.m. and 4 p.m., Monday through Friday, except Federal 
holidays.
    We will consider all comments we receive by the closing date for 
comments. We may change these special conditions based on the comments 
we receive.
    If you want us to acknowledge receipt of your comments on these 
special conditions, include with your comments a self-addressed, 
stamped postcard on which you have written the docket number. We will 
stamp the date on the postcard and mail it back to you.

Background

    On March 6, 2008, Northwest Airspace Technologies, Inc. (NAT), 2210 
Hewitt Avenue, Suite 300, Everett, WA 98201, 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

[[Page 23613]]

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 cushions. With the seat design being 
mostly fabric and metal, their 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, NAT 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: Sec.  
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. Sec.  11.19 
and 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 feature: 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. 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 included only small amounts of non-
metallic materials. We determined that the overall effect of these 
materials on survivability was negligible, whether or not the food 
trays met the heat-release and smoke-emission 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

[[Page 23614]]

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 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.''
    On October 17, 1997, the FAA issued Policy Memorandum 97-112-39, 
Guidance for Flammability Testing of Seat/Console Installations, 
(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 2004, we focused attention on the appropriate 
flammability standards for passenger seats that incorporated non-
traditional, large, non-metallic panels in lieu of the traditional 
fabric-covered metal. 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 issued to apply the 
standards defined in Sec.  25.853(d) to seats designed with large, non-
metallic panels.

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-emission 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-emission 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 NAT 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.

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.
    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 return-to-service date for the Boeing 
Model 757 series airplane, modified by NAT, is imminent, the FAA finds 
that good cause exists to make these special conditions effective upon 
issuance.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.


0
The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Special Conditions

0
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 NAT.
    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 (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 May 11, 2009.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E9-11723 Filed 5-19-09; 8:45 am]
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