[Federal Register Volume 68, Number 165 (Tuesday, August 26, 2003)]
[Proposed Rules]
[Pages 51203-51205]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-21769]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM259; Notice No. 25-03-06-SC]


Special Conditions: Bombardier Aerospace Model BD-100-1A10; Side-
Facing Single Occupancy Seats

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed special conditions.

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SUMMARY: This notice proposes special conditions for the Bombardier 
Aerospace Model BD-100-1A10 airplane. This airplane as modified by 
Learjet Inc. (Subsidiary of Bombardier Aerospace) will have novel or 
unusual design features associated with side-facing single-occupant 
seats. The applicable airworthiness regulations do not contain adequate 
or appropriate safety standards for these design features. 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: Comments must be received on or before September 25, 2003.

ADDRESSES: Comments on this proposal may be mailed in duplicate to: 
Federal Aviation Administration, Transport Airplane Directorate, Attn: 
Rules Docket (ANM-113), Docket No. NM259, 1601 Lind Avenue SW., Renton, 
Washington, 98055-4056; or delivered in duplicate to the Transport 
Airplane Directorate at the above address. Comments must be marked: 
Docket No. NM259. 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: Michael Thompson, FAA, Airframe/Cabin 
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington, 98055-
4056; telephone (425) 227-1157; facsimile (425) 227-1149.

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 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 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 11, 2003, Learjet Inc. (subsidiary of Bombardier 
Aerospace) applied for a supplemental type certificate for installation 
of single-occupant side-facing seats on Bombardier BD-100-1A10 
airplanes. Bombardier Aerospace has requested that special conditions 
be issued for these seats and that the special conditions be listed on 
the type certificate data sheet of the BD-100-1A10 airplane. The Model 
BD-100-1A10 is a twin engine, turbofan powered, transport category 
airplane which is currently the subject of a type certification 
program.
    Section 25.785(a) at Amendment 25-64 requires that each seat ``at 
each station designated as occupiable during takeoff and landing must 
be designed so that persons occupying these seats will not suffer 
serious injury in an emergency landing as a result of the inertia 
forces specified in Sec. Sec.  25.561 and 25.562.'' Additionally, Sec.  
25.562 requires dynamic testing of all seats that are occupied during 
takeoff and landing. However, side-facing seats are considered a novel 
design for transport

[[Page 51204]]

category airplanes that include Amendment 25-64 in the certification 
basis and were not considered when those airworthiness standards were 
promulgated. Hence, the existing regulations do not provide adequate or 
appropriate safety standards for occupants of side-facing seats. In 
order to provide a level of safety that is equivalent to that afforded 
occupants of forward and aft facing seats, additional airworthiness 
standards in the form of special conditions are necessary.
    These special conditions are applicable only to single-occupant 
side-facing seats. They are not sufficient or intended to be used for 
the certification of multiple-occupant side-facing divans or sofas.

Type Certification Basis

    Under the provisions of Sec.  21.101, Learjet Inc. (subsidiary of 
Bombardier Aerospace) must show that the Model BD-100-1A10 airplane, as 
changed, continues to meet the applicable provisions of the regulations 
incorporated by reference in T00005NY 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 T00005NY are as follows:
    14 CFR part 25, effective February 1, 1965, as amended by 
Amendments 25-1 through 25-98; 14 CFR part 34, effective September 10, 
1990.
    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 Bombardier Aerospace Model BD-100-
1A10 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 Bombardier Aerospace Model BD-100-1A10 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.
    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.
    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, the special conditions would also apply to the 
other model.

Novel or Unusual Design Features

    Bombardier Aerospace has proposed to install single-occupant side-
facing seats on BD-100-1A10 airplanes. Section 25.785(b) requires that 
each seat ``at each station designated as occupiable during takeoff and 
landing must be designed so that persons occupying these seats will not 
suffer serious injury in an emergency landing as a result of the 
inertia forces specified in Sec. Sec.  25.561 and 25.562.'' 
Additionally, Sec.  25.562 requires dynamic testing of all seats that 
are occupied during takeoff and landing. However, side-facing seats are 
considered a novel design for transport category airplanes that include 
Amendment 25-64 in the certification basis, and were not considered 
when those airworthiness standards were promulgated. Hence, the 
existing regulations do not provide adequate or appropriate safety 
standards for occupants of side-facing seats. In order to provide a 
level of safety that is equivalent to that afforded occupants of 
forward and aft facing seats, additional airworthiness standards, in 
the form of special conditions, are necessary.

Discussion

    The following special conditions are considered to provide 
occupants of single-occupancy side-facing seats a level of safety that 
is equivalent to that afforded occupants of forward and aft facing 
seats. These special conditions supplement 14 CFR part 25 and, more 
specifically, they supplement Sec. Sec.  25.785 and 25.562.

Applicability

    As discussed above, these special conditions are applicable to the 
Bombardier Aerospace Model BD-100-1A10. Should Bombardier Aerospace 
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.

Conclusion

    This action affects only certain novel or unusual design features 
on one model 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.

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 Bombardier Aerospace Model BD-100-1A10 airplanes. In addition to 
the airworthiness standards of Sec. Sec.  25.562 and 25.785, the 
minimum acceptable standards for dynamic certification of Model BD-100-
1A10 single-occupant side-facing seats are proposed as follows:

Injury Criteria

    (a) Existing Criteria: All injury protection criteria of Sec.  
25.562(c)(1) through (c)(6) apply to the occupant of a side-facing 
seat. Head Injury Criterion (HIC) assessments are required only for 
head contact with the seat and/or adjacent structures.
    (b) Body-to-Wall/Furnishing Contact: The seat must be installed aft 
of a structure, such as an interior wall or furnishing, that will 
support the pelvis, upper arm, chest, and head of an occupant seated 
next to the structure. A conservative representation of the structure 
and its stiffness must be included in the tests. It is recommended, but 
not required, that the contact surface of this structure be covered 
with at least two inches of energy absorbing protective padding (foam 
or equivalent), such as Ensolite.
    (c) Thoracic Trauma: The Thoracic Trauma Index (TTI) injury 
criterion must be substantiated by dynamic test or by rational 
analysis, based on a previous test or tests of a similar seat 
installation. Testing must be conducted with a Side Impact Dummy (SID), 
as defined by 49 CFR Part 572, Subpart F, or its equivalent. TTI must 
be less than 85, as defined in 49 CFR Part 572, Subpart F. TTI data 
must be processed as defined in Federal Motor Vehicle Safety Standard 
(FMVSS) Part 571.214, section S6.13.5.
    (d) Pelvis: Pelvic lateral acceleration must be shown by dynamic 
test or by rational analysis based on previous test(s) of a similar 
seat installation to not exceed 130g. Pelvic acceleration data must be 
processed as defined in FMVSS Part 571.214, section S6.13.5.
    (e) Shoulder Strap Loads: Where upper torso straps (shoulder 
straps) are used for occupants, tension loads in individual straps must 
not exceed 1,750 pounds. If dual straps are used for restraining the 
upper torso, the total

[[Page 51205]]

strap tension loads must not exceed 2,000 pounds.

Test Requirements

    The above performance measures must not be exceeded during the 
following dynamic tests:
    (a) Conduct a longitudinal test per Sec.  25.562(b)(2) with a SID, 
undeformed floor, no yaw, and with all lateral structural supports 
(armrests/walls).
    Pass/fail injury assessments: TTI and pelvic acceleration.
    (b) Conduct a longitudinal test per Sec.  25.562(b)(2) with the 
Hybrid II ATD, deformed floor, 10 degrees yaw, and with all lateral 
structural supports (armrests/walls).
    Pass/fail injury assessments: HIC, upper torso restraint load, 
restraint system retention and pelvic acceleration.
    (c) Conduct a downward vertical test per Sec.  25.562(b)(1) with a 
modified Hybrid II ATD with existing pass/fail criteria.

    Issued in Renton, Washington, on August 18, 2003.
Kyle Olsen,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-21769 Filed 8-25-03; 8:45 am]
BILLING CODE 4910-13-P