[Federal Register Volume 69, Number 184 (Thursday, September 23, 2004)]
[Proposed Rules]
[Pages 56961-56963]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-21393]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM198; Notice No. 25-04-03-SC]


Special Conditions: Boeing Model 777 Series Airplanes; Seats With 
Inflatable Lapbelts

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed amendment of special conditions.

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SUMMARY: This notice proposes amended special conditions for Boeing 
Model 777 series airplanes. These airplanes, manufactured by Boeing 
Commercial Airplanes, have novel or unusual design features associated 
with seats with inflatable lapbelts. Special Conditions No. 25-187-SC 
were issued on October 3, 2001, addressing this issue. The proposed 
amendment would add a new requirement that addresses the flammability 
of the material used to construct the inflatable lapbelt. The 
applicable airworthiness regulations do not contain adequate or 
appropriate safety standards for this design feature. The amended 
special conditions would contain the additional safety standards that 
the Administrator considers necessary to establish an appropriate level 
of safety considering the safety benefits associated with the 
inflatable lapbelt.

DATES: Comments must be received on or before October 13, 2004.

ADDRESSES: You may send comments, identified by Docket No. NM198, using 
any of the following methods:
     Mail: Federal Aviation Administration, Transport Airplane 
Directorate, ANM-113, Attn: Rules Docket, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
     Fax: 1-425-227-1232, Attn: Jayson Claar.
     Electronically: [email protected].

FOR FURTHER INFORMATION CONTACT: Jayson Claar, FAA, Airframe and Cabin 
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue, SW., Renton, Washington, 
98055-4056; telephone (425) 227-2194.

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 proposed 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. 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 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

[[Page 56962]]

filed late if it is possible to do so without incurring expense or 
delay. We may change these special conditions in light of 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.

Background

    On April 20, 2001, Boeing Commercial Airplanes, PO Box 3707, 
Seattle, Washington 98124, applied for a type certificate design change 
to install inflatable lapbelts for head injury protection on certain 
seats in Boeing Model 777 series airplanes. The Model 777 series 
airplane is a swept-wing, conventional-tail, twin-engine, turbofan-
powered transport. The inflatable lapbelt is designed to limit occupant 
forward excursion in the event of an accident. This will reduce the 
potential for head injury, as determined by the Head Injury Criteria 
(HIC) measurement. The inflatable lapbelt behaves similarly to an 
automotive airbag, but in this case the airbag is integrated into the 
lapbelt, and inflates away from the seated occupant. While airbags are 
now standard in the automotive industry, the use of an inflatable 
lapbelt is novel for commercial aviation.
    Because the existing airworthiness standards of 14 CFR part 25 do 
not address inflatable lapbelts, the FAA developed special conditions 
to address this design feature. Special Conditions No. 25-187-SC were 
issued to Boeing Commercial Airplanes on October 3, 2001, and published 
in the Federal Register on October 12, 2001 (66 FR 52017).
    On February 26, 2004, The Boeing Company requested that the FAA 
amend SC No. 25-187-SC to address flammability of the airbag material. 
During the development of the inflatable lapbelt the manufacturer was 
unable to develop a fabric that would meet the inflation requirements 
for the bag and the flammability requirements of Part I(a)(1)(i) of 
appendix F to part 25. The fabrics that were developed that meet the 
flammability requirement did not produce acceptable deployment 
characteristics. However, the manufacturer was able to develop a fabric 
the meets the less stringent flammability requirements of Part 
I(a)(1)(iv) of appendix F to part 25 and has acceptable deployment 
characteristics.

Discussion

    Part I of appendix F to part 25 specifies the flammability 
requirements for interior materials and components. There is no 
reference to inflatable restraint systems in appendix F because such 
devices did not exist at the time the flammability requirements were 
written. The existing requirements are based on both material types, as 
well as use, and have been specified in light of the state-of-the-art 
of materials available to perform a given function. In the absence of a 
specific reference, the default requirement would be for the type of 
material used to construct the inflatable restraint, which is a fabric 
in this case. However, in writing a special condition, the FAA must 
also consider the use of the material, and whether the default 
requirement is appropriate. In this case, the specialized function of 
the inflatable restraint means that highly specialized materials are 
needed. The standard normally applied to fabrics is a 12-second 
vertical ignition test. However, materials that meet this standard do 
not perform adequately as inflatable restraints. Since the safety 
benefit of the inflatable restraint is very significant, the 
flammability standard appropriate for these devices should not screen 
out suitable materials, thereby effectively eliminating use of 
inflatable restraints. The FAA will need to establish a balance between 
the safety benefit of the inflatable restraint and its flammability 
performance. At this time, the 2.5 inch per minute horizontal test is 
considered to provide that balance. As the state-of-the-art in 
materials progresses (which is expected), the FAA may change this 
standard in subsequent special conditions to account for improved 
materials.
    The additional proposed safety standard would be added as Item 14 
to existing SC 25-187-SC. Although Items 1 through 13 are standards 
already adopted in Special Conditions No. 25-187-SC and are not subject 
to further public comment, they are repeated later in this notice in 
order to place the additional standard in proper perspective.

Type Certification Basis

    Under the provisions of Sec. 21.101, Boeing Commercial Airplanes 
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: Amendments 25-1 through 25-82 for the Model 777-200, 
and amendments 25-1 through 25-86 with exceptions for the Model 777-
300. The U.S. type certification basis for the Model 777 is established 
in accordance with Secs. 21.29 and 21.17 and the type certification 
application date. The U.S. type certification basis is listed in Type 
Certificate Data Sheet No. T00001SE.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., part 25 as amended) do not contain adequate or 
appropriate safety standards for 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 must comply with the fuel vent and 
exhaust emission requirements of part 34 and the noise certification 
requirements of 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.

Applicability

    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 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 the provisions of Sec. 21.101.

Public Comment Period

    Delivery of Model 777 airplanes with the additional flammability 
standard is currently scheduled for January 2006. Because a delay would 
significantly affect the applicant's installation and type 
certification of the airbag material, the public comment period is 20 
days.

Conclusion

    This action affects only certain novel or unusual design features 
on the Boeing Model 777 series airplanes. It is not a rule of general 
applicability, and it affects only Model 777 series airplanes listed on 
Type Certificate Data Sheet T00001SE.

[[Page 56963]]

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

Authority Citation

    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 proposes the 
following additional special condition (Item No. 14) as part of the 
type certification basis for the Boeing Model 777 series airplanes with 
inflatable lapbelts installed. (Existing special condition Items 1-13 
are repeated below for clarity only.).
    1. Seats With Inflatable Lapbelts. It must be shown that the 
inflatable lapbelt will deploy and provide protection under crash 
conditions where it is necessary to prevent serious head injury. The 
means of protection must take into consideration a range of stature 
from a two-year-old child to a ninety-fifth percentile male. The 
inflatable lapbelt must provide a consistent approach to energy 
absorption throughout that range. In addition, the following situations 
must be considered:
    a. The seat occupant is holding an infant.
    b. The seat occupant is a child in a child restraint device.
    c. The seat occupant is a child not using a child restraint device.
    d. The seat occupant is a pregnant woman.
    2. The inflatable lapbelt must provide adequate protection for each 
occupant regardless of the number of occupants of the seat assembly, 
considering that unoccupied seats may have active seatbelts.
    3. The design must prevent the inflatable lapbelt from being either 
incorrectly buckled or incorrectly installed such that the inflatable 
lapbelt would not properly deploy. Alternatively, it must be shown that 
such deployment is not hazardous to the occupant and will provide the 
required head injury protection.
    4. It must be shown that the inflatable lapbelt system is not 
susceptible to inadvertent deployment as a result of wear and tear, or 
inertial loads resulting from in-flight or ground maneuvers (including 
gusts and hard landings), likely to be experienced in service.
    5. Deployment of the inflatable lapbelt must not introduce injury 
mechanisms to the seated occupant, or result in injuries that could 
impede rapid egress. This assessment should include an occupant who is 
in the brace position when it deploys and an occupant whose belt is 
loosely fastened.
    6. It must be shown that an inadvertent deployment that could cause 
injury to a standing or sitting person is improbable.
    7. It must be shown that inadvertent deployment of the inflatable 
lapbelt during the most critical part of the flight will either not 
cause a hazard to the airplane or is extremely improbable.
    8. It must be shown that the inflatable lapbelt will not impede 
rapid egress of occupants 10 seconds after its deployment.
    9. The system must be protected from lightning and HIRF. The 
threats specified in Special Condition No. 25-ANM-78 are incorporated 
by reference for the purpose of measuring lightning and HIRF 
protection. For the purposes of complying with HIRF requirements, the 
inflatable lapbelt system is considered a ``critical system'' if its 
deployment could have a hazardous effect on the airplane; otherwise it 
is considered an ``essential'' system.
    10. The inflatable lapbelt must function properly after loss of 
normal aircraft electrical power, and after a transverse separation of 
the fuselage at the most critical location. A separation at the 
location of the lapbelt does not have to be considered.
    11. It must be shown that the inflatable lapbelt will not release 
hazardous quantities of gas or particulate matter into the cabin.
    12. The inflatable lapbelt installation must be protected from the 
effects of fire such that no hazard to occupants will result.
    13. There must be a means for a crewmember to verify the integrity 
of the inflatable lapbelt activation system prior to each flight or it 
must be demonstrated to reliably operate between inspection intervals.
    14. The inflatable material may not have an average burn rate of 
greater than 2.5 inches/minute when tested using the horizontal 
flammability test as defined in 14 CFR part 25, appendix F, part I, 
paragraph (b)(5). As the state-of-the-art in materials progresses 
(which is expected), the FAA may change this standard in subsequent 
special conditions to account for improved materials.

    Issued in Renton, Washington, on September 17, 2004.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-21393 Filed 9-22-04; 8:45 am]
BILLING CODE 4910-13-P