[Federal Register Volume 72, Number 131 (Tuesday, July 10, 2007)]
[Rules and Regulations]
[Pages 37425-37430]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 07-3339]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM359; Special Conditions No. 25-358-SC]


Special Conditions: Boeing Model 737 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 737 
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 
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.

EFFECTIVE DATE: The effective date of these special conditions is 
August 9, 2007.

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 [email protected].

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 August 8, 2005, Boeing Commercial Airplanes, P.O. Box 3707, 
Seattle, Washington 98124, applied for a design change to Type 
Certificate No. A16WE for installation of seats that include non-
traditional, large, non-metallic panels in Boeing Model 737-700 series 
airplanes. The Boeing Model 737 series airplanes, currently approved 
under Type Certificate No. A16WE, are swept-wing, conventional-tail, 
twin-engine, turbofan-powered, single aisle, medium sized transport 
category airplanes.
    The applicable regulations for airplanes currently approved under 
Type Certificate No. A16WE 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 V, heat release and smoke emission 
requirements.

Type Certification Basis

    Under the provisions of 14 CFR 21.101, Boeing must show that the 
Model 737 series airplanes, as changed, continue to meet the applicable 
provisions of the regulations incorporated by reference in Type 
Certificate No. A16WE, or the applicable

[[Page 37426]]

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. A16WE are 
as follows: Title 14 CFR part 25, as amended by Amendment 25-1 through 
Amendment 25-15, for the Models 737-200, -200C, -300, -400, and -500. 
Title 14 CFR part 25, as amended by Amendment 25-1 through Amendment 
25-77, for the Models 737-600, -700, and -800, with the exceptions 
listed: Section 25.853(d)(3), Compartment interiors, at Amendment 25-
72; and equivalent safety findings, Sec.  25.853(f), Compartment 
interiors. Title 141 CFR part 25, as amended by Amendment 25-1 through 
Amendment 25-91, for the Models 737-700C and -900, with the exceptions 
listed: Section 25.853(d)(3), Compartment interiors, at Amendment 25-
72; and equivalent safety findings, Sec.  25.853(f), Compartment 
interiors. Title 14 CFR part 25, as amended by Amendment 25-1 through 
Amendment 25-108, for the models 737-900ER, with the exceptions listed: 
Section 25.853(d)(3), Compartment interiors, at Amendment 25-72; and 
equivalent safety findings, Section 25.853(f), Compartment interiors.
    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., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the Boeing Model 737 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 737 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 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 737 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 those panels directly exposed 
to the passenger cabin in the traditional sense, plus those panels 
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, April16, 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 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

[[Page 37427]]

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.

Discussion of Comments

    Notice of proposed special conditions No. 25-06-13-SC, pertaining 
to Boeing Model 737 series airplanes, was published in the Federal 
Register on November 9, 2006. Comments were received from Air Tran, 
Airbus, B/E Aerospace, Boeing, Delta Engineering, the International 
Coordinating Council of Aerospace Industries Associations (ICCAIA), 
KLM, and Weber Aircraft LP.

Special Conditions Are Not the Appropriate Means To Establish These 
Requirements

    Airbus, Boeing, Delta Engineering, ICCAIA, and Weber suggested that 
the proposed special conditions were not the appropriate way to 
establish these requirements. These commenters suggested that either 
the seat technical standard order (TSO) be revised to include the 
requirements, or that formal rulemaking activity take place to amend 
Title 14 CFR part 25.
    The commenters stated that including the requirements in either the 
seat TSO or an amendment to part 25 would ensure that the requirements 
were applied equally and consistently throughout the FAA and industry. 
Airbus stated that if the requirements were located in the seat TSO it 
would reduce the overall administrative burden by requiring a single 
showing of compliance for a given seat design that may be installed in 
different types of airplanes.
    FAA Response: We believe that including these requirements in the 
context of special conditions is appropriate. The proliferation of the 
use of large, non-metallic panels in the construction of seats has 
created a need to issue special conditions to maintain the current 
level of safety. Special conditions are the best way of introducing 
these requirements until we determine it is necessary to amend part 25 
through the rulemaking process. Also, seats are not required to follow 
guidance in a TSO to be eligible for installation on an airplane. 
Furthermore, the proposed TSO C127b includes these standards as 
optional criteria.

Request To Add Airplane Models to the Applicability

    Air Trans, Boeing, Delta Engineering, ICCAIA, and Weber all 
suggested that the applicability of the proposed special conditions be 
expanded and not limited to only Boeing Model 737 series airplanes. The 
commenters noted that other airplane models certified under 14 CFR part 
25 include the same design features identified as ``novel or unusual'' 
on Boeing Model 737 series airplanes.
    FAA Response: We agree that many other airplane models certified 
under 14 CFR part 25 include ``novel or unusual'' design features 
similar to those on Boeing Model 737 series airplanes. We are 
developing model-specific special conditions for all transport category 
airplanes operating under part 121 regulations. We will continue to 
issue special conditions regarding this subject until part 25 is 
formally amended through the rulemaking process. If part 25 is amended, 
these requirements will have general applicability instead of model-
specific applicability. We are currently using a similar approach for 
high intensity radiated fields (HIRF) special conditions. The HIRF 
special conditions will continue to be issued on a model-specific basis 
until part 25 is amended to include regulations applicable to HIRF.

Request To Add Airplanes Operating Under Part 129 to the Applicability

    Delta Engineering questioned why the proposed special conditions 
would be applicable to airplanes operated under 14 CFR part 121 and 
would not be applicable to airplanes operated under 14 CFR part 129. 
Delta Engineering provided the example of an airplane with a foreign 
registration. Per the applicability of the proposed special conditions, 
the requirements of the proposed special conditions would not be 
applicable because the airplane would be operated in compliance with 
part 129 operating rules instead of part 121 operating rules.
    FAA Response: As discussed previously, our intent in adopting these 
special conditions is to apply them to airplanes that are already 
required to comply with the smoke and heat release requirements adopted 
in Amendment 25-61 and Amendment 25-66. Model 737 airplanes with this 
amendment in their certification basis * are subject to these special 
conditions, regardless of the operational regulatory parts under which 
they are operated. Certain other airplanes operated under part 121 are 
also subject to these requirements as a result of Sec.  121.312, as 
amended by Amendment 121-189, even if their certification basis does 
not include Amendment 25-61. However, airplanes with a certification 
basis preceding Amendment 25-61 and not subject to Sec.  121.312 are 
not required to comply either with Sec.  25.853 or with these special 
conditions.
---------------------------------------------------------------------------

    \*\ Model 737-600, -700, -700C, -800, and -900 as of the 
effective date of these special conditions.
---------------------------------------------------------------------------

Request To Clarify the Effects of the Proposed Special Conditions on 
the Existing Fleet

    Air Trans and KLM expressed concern that the requirements in the 
proposed special conditions would be retroactive and affect the 
existing airplane fleet or follow-on deliveries of airplanes with 
previously certified interiors.
    FAA Response: We have added a new special condition 4 in these 
special conditions to clarify that only airplanes associated with new 
seat certification programs 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 will not be affected.

[[Page 37428]]

Request for Justification Regarding Selection of Materials and 
Quantitative Limits

    Air Tran, B/E Aerospace, and Weber questioned how 1.5 square feet 
became the maximum area of non-metallic material per seat. B/E stated 
that the proposed special conditions need further review because the 
exclusion does not adequately address items traditionally mounted on 
seat backs. B/E specifically asked if large video monitors would have 
to comply when installed in seat backs or large, non-metallic panels.
    Weber stated that the proposed special conditions include many 
exclusions based on the size and location of material. Weber also 
stated that the quantitative limits for these exclusions do not appear 
to be based on data. Weber suggested that the proposed special 
conditions be revised to include justification for the quantitative 
limits. Furthermore, Weber stated that due to the number of passenger 
places, First Class seats are limited to a much smaller amount of non-
compliant material than Tourist Class seats, despite the fact that 
there are fewer First Class seats per area of the passenger cabin. 
Larger seats with fewer passenger places should not have lower 
quantitative limits on non-compliant material.
    Weber also stated that, based on observation of airplane cabins and 
the amount of materials in a seat design, the following statement in 
the proposed special conditions is incorrect: ``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.''
    FAA Response: In 1993, the FAA published a report (DODT/FAA/CT-
TN93-13) documenting the results of full-scale testing using panels on 
seats that did, or did not, comply with heat release and smoke 
emissions requirements. Those test results showed that limited 
quantities of material on seats that did not meet heat release and 
smoke emissions requirements did not raise a safety issue. Amendment 
25-83 states that, based on this testing, components 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 can be made regarding 
whether or not they have to meet the heat release and smoke density 
regulations. Based on that information we determined that 1.5 feet of 
non-metallic material per seat is appropriate.
    In response to B/E Aerospace's comment, video monitor installations 
are not affected by these special conditions. There are existing 
flammability regulations that cover those installations.
    In response to Weber's comment regarding the size limitations, as 
noted above, we believe that the quantitative limits are justified. 
These size limitations are consistent with full-scale test data and the 
design criteria developed at the time Amendment 25-61 was adopted. 
Also, these size limitations were considered during the rulemaking 
process for Amendment 25-61.
    In response to Weber's comment regarding our statement that the 
surface areas of some seat installations are equivalent to the amount 
of material in sidewall and overhead stowage bin interior panels, in 
our review of applicants' proposed furnishings for passenger cabin 
installations, we have noticed an increase in the use of large, non-
metallic material in proposed seating configurations. Based on those 
reviews, we believe that our statement is correct.

Request To Revise the Type Certification Basis Section

    Boeing noted that the amendment levels for some of the airplanes 
were incorrectly cited in the Type Certification Basis section of the 
proposed special conditions.
    FAA Response: We have revised the Type Certification Basis section 
to incorporate Boeing's recommended changes.

Request for Clarification of the Testing Method in the ``Clarification 
of Exposed'' Paragraph

    B/E Aerospace asked if the non-traditional, large, non-metallic 
panels covered with traditional fabrics or leathers could be tested 
without the dress cover. Boeing suggested that the words ``or method of 
covering attachment'' be added in the last sentence of the 
``Clarification of Exposed'' paragraph.
    FAA Response: We agree to revise the last sentence of the 
``Clarification of Exposed'' paragraph to address B/E Aerospace's 
question and incorporate Boeing's suggestion. In these special 
conditions that sentence now states ``Non-traditional, large, non-
metallic panels covered with traditional fabrics or leathers will be 
tested without their coverings or covering attachments.''

Request for Clarification Regarding Fabric and Thermoplastic Panels

    Airbus requested that the FAA provide information regarding whether 
or not fabric covered panels are less threatening than thermoplastic 
ones. No justification was provided for this request.
    FAA Response: The standards for using fabric, thermoplastic, and 
leather have been previously established and are applied separately.

Request for a Better Description of Traditional and Non-Traditional 
Areas/Furnishings

    Airbus requested a better description of the console size in the 
``Definition of `Non-Traditional, Large, Non-Metallic Panel' '' 
paragraph of the proposed special conditions. Airbus noted that in the 
proposed special conditions ``Center Consoles'' are listed as 
``traditional exempted areas.'' Airbus stated that this may be true for 
small consoles that ``* * * do not protrude the standard seat cushion 
geometries. However, it is understood that large consoles (which do 
also divide the forward legroom) are expected to comply with HRR/SD 
[heat release and smoke density] criteria.'' Airbus suggested that this 
issue should be clarified because FAA Memorandum 97-112-39, Guidance 
for Flammability Testing of Seat/Console Installations, addresses those 
larger, separate consoles.
    B/E Aerospace stated that the definition of non-traditional areas 
was not adequate and asked about seat backs, seat bottoms, and kick 
panels. This commenter also asked if fire blocking material is 
considered a traditional fabric.
    FAA Response: We agree and have revised this paragraph to include 
``credenzas'' as an additional example of non-traditional areas and 
``armrest-styled center consoles'' as an additional example of 
traditionally exempted areas. In this final special condition the 
revised sentences appear as follows: ``Examples of nontraditional areas 
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 areas include: arm caps, armrest 
close-outs such as end bays and armrest-styled center consoles, food 
trays, video monitors and shrouds.''

Request for Additional Testing by the FAA

    Airbus, Delta Engineering, ICCAIA, and KLM commented that the FAA 
should conduct additional testing prior

[[Page 37429]]

to implementing the proposed special conditions. Airbus and KLM 
provided similar statements that tests with different amounts of non-
traditional, large, non-metallic panels on seats have never been 
performed to evaluate to what extent the increase in the flammability 
standard of those seat parts might influence fire safety. ICCAIA stated 
that the FAA should perform testing to confirm the benefit of issuing 
the proposed special conditions. ICCAIA noted that seat back shells may 
be made from parts created from a combination of different materials 
and sizes. As a result, application of the proposed special conditions 
would result in multiple tests to determine if the seat back shells 
were compliant, and the test results would be open to interpretation.
    Delta Engineering stated that the proposed special condition does 
not provide information regarding the smoke density and heat release 
aspects of traditional seat components and that, through testing, the 
FAA should establish the safety gains related to having the large 
composite panel compliant with the existing heat release and smoke 
density requirements. This commenter also stated that the smoke 
emissions from the seat cushion foam may negate any safety gain related 
to having the large composite panel compliant with smoke density 
requirements. In addition, this commenter also questioned whether the 
FAA conducted extensive testing to confirm that the regulatory 
standards now being applied to passenger seats are compatible with the 
requirements in the proposed special conditions.
    FAA Response: As stated in the proposed special conditions, the FAA 
has conducted extensive research on the effects of post-crash 
flammability in the passenger cabin. As a result of that research, 
combined with service experience, we adopted new airworthiness 
standards for interior surfaces associated with large surface area 
parts. The proliferation of the use of large, non-metallic panels in 
the construction of seats was not anticipated when those airworthiness 
standards were issued. This increased use of large, non-metallic panels 
in seating configurations has created a need to issue special 
conditions to provide the level of passenger protection intended by 
those airworthiness standards. Seat cushion standards are a separate 
consideration and were taken into account when these special conditions 
were created.
    Furthermore, testing is not required to issue special conditions. 
The basis for issuing special conditions is that the applicable 
airworthiness regulations do not contain adequate or appropriate safety 
standards for a ``novel or unusual'' design feature.

Request for a Cost-Benefit Analysis

    Airbus, B/E Aerospace, ICCAIA, and Weber noted that the proposed 
special conditions did not include a cost-benefit analysis to support 
the proposed requirements. Airbus suggested that a cost-benefit 
analysis should be done through the traditional rulemaking process. 
ICCAIA stated that the cost-benefit analysis should be conducted 
because the requirements in the proposed special conditions would be 
applied to other airplane makes and models. B/E Aerospace and Weber 
provided similar statements regarding the cost impact to seat 
manufacturers. Those commenters stated that compliant material is 
limited and expensive. Weber also stated that significant time and 
costs would be involved in modifying current designs and developing new 
materials to comply with the proposed special conditions.
    FAA Response: When Amendment 25-61 went through the formal 
rulemaking process a formal economic regulatory analysis was provided. 
These special conditions effectively serve to maintain the benefits 
achieved in that amendment by providing an equivalent level of safety 
for the novel or unusual design feature described earlier. Under 
Executive Order 12866, these analyses are required only for rules of 
general applicability. A cost-benefit analysis is not part of the 
process for proposing special conditions, which apply only to a 
specified type certificate and are not rules of general applicability.

Request To Clarify the Effective Date of the Proposed Special 
Conditions

    Air Trans and Boeing both commented on the effective date of the 
proposed special conditions. Air Trans stated that the proposed special 
conditions did not include an effective date. Boeing commented that 
these proposed special conditions should not be applicable upon 
publication and should not be applicable to the first delivered Model 
737-900ER airplane. Boeing noted that it typically takes at least one 
year for seat manufacturers to incorporate major design changes, such 
as those required in the proposed special conditions.
    FAA Response: In response to Air Trans' statement, under standard 
practice, the effective date of final special conditions is 30 days 
after the date of publication in the Federal Register. These special 
conditions follow this practice and will be applicable to all type 
design changes that include new seat approvals applied for after the 
effective date of these special conditions.
    In response to Boeing's comment, as stated previously, the issue 
regarding large, non-metallic seats is a long standing one and has 
generated many discussions between the FAA and the aviation industry. 
Through the Seattle Aircraft Certification Office the FAA has made 
Boeing aware of the requirements in these special conditions. Since the 
time the proposed special conditions were published for public comment, 
the first Boeing Model 737-900ER airplane was delivered; therefore, 
these special conditions are not applicable to the approved arrangement 
on that airplane.

Request To Extend the Public Comment Period

    Boeing requested that the public comment period for the proposed 
special conditions be extended from 20 days to 60 days. Boeing stated 
that the proposed special conditions would require significant design 
changes to seat components. Airframe and seat manufacturers would need 
to assess the economic impact of the proposed special conditions and 
communicate that information to the FAA.
    FAA Response: The subject of large, non-metallic seat panels is a 
long standing issue between the FAA and the aviation industry. We have 
had ongoing discussions with industry representatives in an effort to 
work out a solution, and the results of these discussions are reflected 
in these special conditions. We do not agree that an extension to the 
public comment period is needed or would result in further changes to 
these special conditions.
    Except as noted above, these special conditions are adopted as 
proposed.

Applicability

    As discussed above, these special conditions are applicable to 
Boeing Model 737 series airplanes. 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 or unusual design 
feature, the special conditions would apply to that model as well.
    Seats do not have to meet these special conditions when installed 
in compartments that are not otherwise required to meet the test 
requirements of Title 14 CFR part 25, Appendix F, parts IV and V. For 
example, airplanes that do not have Sec.  25.853, Amendment 25-61 or 
later, in their certification basis and those airplanes that do not 
need to comply with the requirements of 14 CFR 121.312.

[[Page 37430]]

    Only airplanes associated with new certification programs applied 
for after the effective date of these special conditions will be 
affected by the requirements in these special conditions. The existing 
airplane fleet and follow-on deliveries of airplanes with previously 
certified interiors are not affected.

Conclusion

    This action affects only certain novel or unusual design features 
on Boeing Model 737 series airplanes. It is not a rule of general 
applicability.

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 737 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 corporate 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 are not subject to 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 
applied for 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 June 29, 2007.
Stephen P. Boyd,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 07-3339 Filed 7-9-07; 8:45 am]
BILLING CODE 4910-13-M