[Federal Register Volume 71, Number 217 (Thursday, November 9, 2006)]
[Proposed Rules]
[Pages 65759-65762]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-18906]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM359; Notice No. 25-06-13-SC]


Special Conditions: Boeing Model 737 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 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 
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 29, 2006.

ADDRESSES: You must mail two copies of your comments to: Federal 
Aviation Administration, Transport Airplane Directorate, Attn: Rules 
Docket (ANM-113), Docket No. NM359, 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. NM359. 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 A. 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; electronic 
mail [email protected].

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.

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,

[[Page 65760]]

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 to 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 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, -500, and -600. Title 14 CFR part 
25, as amended by Amendment 25-1 through Amendment 25-91, for the 
Models 737-700, -700C, -800, -900, and -900ER, 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.
    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 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 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.

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 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

[[Page 65761]]

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://www.airweb.faa.gov/Regulatory--and--Guidance--
Library/rgPolicy.nsf/0/180fc146e245add486256d49006d29bd/$FILE/
Oct1797.pdf). 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.

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 
non-traditional areas include, but are not limited to: seat backs, 
bottoms and leg/foot rests, kick panels, back shells and associated 
furniture. Examples of traditional exempted areas include: arm caps, 
armrest close-outs such as end bays and 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.

Applicability

    As discussed above, these special conditions are applicable to 
Boeing Model 737 series airplanes. Although the heat release and smoke 
testing requirements of Sec.  25.853 per Appendix F, parts IV and V, 
are not part of the part 25 certification basis for the Model 737-200, 
-200C, -300, -400, -500, and -600, these special conditions are 
applicable if the airplanes are in 14 CFR part 121 service. Part 121 
requires applicable interior panels to comply with Sec.  25.853, 
Appendix F, parts IV and V, regardless of the certification basis. It 
is not our intent 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. 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.
    Certification of the Boeing Model 737-900ER is currently scheduled 
for February 2007. Because a delay would significantly affect the 
applicant's installation of the affected seats and certification of the 
airplane, the public comment period is shortened to 20 days.

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.
    Based on the above reasoning, we find that the intent of the [heat 
release and smoke emission] standards is to include minimum panel sizes 
on the order of one to two square feet. This panel size sets the 
acceptable level of safety in the cabin. The intent of these special 
conditions is to maintain this accepted level of safety and be 
consistent with the average minimum panel size in the balance of the 
cabin interior. Therefore, we are allowing up to 1.5 square feet of 
non-traditional, non-metallic, panel material per seat place in total 
to be excluded from the heat release and smoke emission standards. 
However, this exclusion [from heat release and smoke emission] does not 
provide the excluded material additional relief from the other 
standards such as Title 14 CFR part 25, Appendix F, parts I and II. 
However, non-traditional, large, non-metallic panels covered with 
traditional fabrics or leathers will be tested without their coverings. 
These coverings 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.
    We recognize different manufacturing techniques have associated 
cost differences and therefore are allowing the applicant to designate 
which non-traditional, non-metallic panels comprise the 1.5 square foot 
exclusion. This determination will allow for flexibility in design and 
a manufacturing cost savings.

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 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 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

[[Page 65762]]

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 smoke and heat release in their 
certification basis and do not need to comply with the requirements per 
14 CFR 121.312, and
    c. Airplanes exempted from smoke and heat release requirements.

    Issued in Renton, Washington, on October 27, 2006.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-18906 Filed 11-8-06; 8:45 am]
BILLING CODE 4910-13-P