[Federal Register Volume 72, Number 80 (Thursday, April 26, 2007)]
[Proposed Rules]
[Pages 20774-20775]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-7840]


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Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

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Federal Register / Vol. 72, No. 80 / Thursday April 26, 2007 / 
Proposed Rules

[[Page 20774]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM373 Special Conditions No. 25-07-09-SC]


Special Conditions: Boeing Model 787-8 Airplane; Composite 
Fuselage In-Flight Fire/Flammability Resistance

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed special conditions.

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SUMMARY: This notice proposes special conditions for the Boeing Model 
787-8 airplane. This airplane will have novel or unusual design 
features when compared to the state of technology envisioned in the 
airworthiness standards for transport category airplanes. The fuselage 
of the Boeing Model 787-8 series airplane will be made of composite 
materials rather than conventional aluminum. While the regulations 
include flame propagation standards for some materials commonly found 
in inaccessible areas of the airplane, they do not yet incorporate 
standards for materials used to construct the fuselage. Therefore, 
special conditions are needed to address 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. Additional special conditions will be issued for other novel 
or unusual design features of the Boeing Model 787-8 airplanes.

DATES: Comments must be received on or before June 11, 2007.

ADDRESSES: Comments on this proposal may be mailed in duplicate to: 
Federal Aviation Administration, Transport Airplane Directorate, 
Attention: Rules Docket (ANM-113), Docket No. NM373, 1601 Lind Avenue 
SW., Renton, Washington 98057-3356; or delivered in duplicate to the 
Transport Airplane Directorate at the above address. All comments must 
be marked Docket No. NM373. Comments may be inspected in the Rules 
Docket weekdays, except Federal holidays, between 7:30 a.m. and 4 p.m.

FOR FURTHER INFORMATION CONTACT: Jeff Gardlin, FAA, Airframe/Cabin 
Safety, ANM-115, Transport Airplane Directorate, Aircraft Certification 
Service, 1601 Lind Avenue SW., Renton, Washington 98057-3356; telephone 
(425) 227-2136; facsimile (425) 227-1320.

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites interested persons to participate in this 
rulemaking by submitting 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 proposed special conditions. The docket is available 
for public inspection 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 notice between 7:30 a.m. and 4 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 the 
proposed special conditions based on 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.

Background

    On March 28, 2003, Boeing applied for an FAA type certificate for 
its new Boeing Model 787-8 passenger airplane. The Boeing Model 787-8 
airplane will be an all-new, two-engine jet transport airplane with a 
two-aisle cabin. The maximum takeoff weight will be 476,000 pounds, 
with a maximum passenger count of 381 passengers.

Type Certification Basis

    Under provisions of 14 CFR 21.17, Boeing must show that Boeing 
Model 787-8 airplanes (hereafter referred to as ``the 787'') meet the 
applicable provisions of 14 CFR part 25, as amended by Amendments 25-1 
through 25-117, except Sec. Sec.  25.809(a) and 25.812, which will 
remain at Amendment 25-115. If the Administrator finds that the 
applicable airworthiness regulations do not contain adequate or 
appropriate safety standards for the 787 because of a novel or unusual 
design feature, special conditions are prescribed under provisions of 
14 CFR 21.16.
    In addition to the applicable airworthiness regulations and special 
conditions, the 787 must comply with the fuel vent and exhaust emission 
requirements of 14 CFR part 34 and the noise certification requirements 
of part 36. In addition, the FAA must issue a finding of regulatory 
adequacy pursuant to section 611 of Public Law 92-574, the ``Noise 
Control Act of 1972.''
    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.  21.17(a)(2).
    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, the special conditions would also 
apply to the other model under provisions of Sec.  21.101.

Novel or Unusual Design Features

    In-flight fires have originated in inaccessible areas of aircraft 
where thermal/acoustic insulation located adjacent to the aluminum 
aircraft skin has been the path for flame propagation and fire growth. 
Although these insulation materials were required to comply with the 
basic ``Bunsen burner'' requirement of title 14 Code of Federal 
Regulations (CFR) sections 25.853(a) and 25.855(d), these incidents 
revealed unexpected flame spread along the insulation film covering 
material of the thermal/acoustic insulation. In all cases, the ignition 
source was relatively modest and, in most cases, was

[[Page 20775]]

electrical in origin (for example an electrical short circuit, arcing 
caused by chafed wiring, or a ruptured ballast case).
    In September 2003, in an effort to limit use of materials that 
sustain or propagate a fire in inaccessible areas, the FAA promulgated 
14 CFR 25.856(a), which requires that thermal/acoustic insulation 
material installed in the fuselage meet newly developed flame 
propagation test requirements. That rule was Amendment 25-111. These 
requirements were developed to address a realistic fire threat. We 
consider that threat generally applicable to the 787.
    Conventional aluminum fuselage material does not contribute to in-
flight fire propagation. As a result, there are no standards that 
address in-flight fire safety of the fuselage structure itself. The 787 
will make extensive use of composite materials in the fabrication of 
the majority of the
    <bullet> Wing,
    <bullet> Fuselage skin,
    <bullet> Stringers,
    <bullet> Spars, and
    <bullet> Most other structural elements of all major sub-assemblies 
of the airplane.

As a result of this extensive use of a new construction material, the 
fuselage cannot be assumed to have the fire resistance previously 
afforded by aluminum during the in-flight fire scenario mentioned 
above. These proposed special conditions would require that the 787 
provide the same level of in-flight survivability as a conventional 
aluminum fuselage airplane. This includes its thermal/acoustic 
insulation meeting requirements of Sec.  25.856(a). Resistance to flame 
propagation must be shown, and all products of combustion that may 
result must be evaluated for toxicity and found acceptable.

Applicability

    As discussed above, these proposed special conditions are 
applicable to the 787. Should Boeing apply at a later date for a change 
to the type certificate to include another model incorporating the same 
novel or unusual design features, these proposed special conditions 
would apply to that model as well under the provisions of Sec.  21.101.

Conclusion

    This action affects only certain novel or unusual design features 
of the 787. It is not a rule of general applicability, and it affects 
only the applicant that applied to the FAA for approval of these 
features on the airplane.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

    The authority citation for these Special Conditions is as follows:

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

The Proposed Special Conditions

    Accordingly, the Administrator of the Federal Aviation 
Administration (FAA) proposes the following special conditions as part 
of the type certification basis for the Boeing Model 787-8 airplane.
    In addition to the requirements of 14 CFR 25.853(a) governing 
material flammability, the following special conditions apply:

    The 787 composite fuselage structure must be shown to be 
resistant to flame propagation under the fire threat used to develop 
14 CFR 25.856(a). If products of combustion are observed beyond the 
test heat source, they must be evaluated and found acceptable.

    Issued in Renton, Washington, on April 18, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-7840 Filed 4-25-07; 8:45 am]
BILLING CODE 4910-13-P