[Federal Register: August 23, 2005 (Volume 70, Number 162)]
[Rules and Regulations]
[Page 49153-49155]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr23au05-1]
========================================================================
Rules and Regulations
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains regulatory documents
having general applicability and legal effect, most of which are keyed
to and codified in the Code of Federal Regulations, which is published
under 50 titles pursuant to 44 U.S.C. 1510.
The Code of Federal Regulations is sold by the Superintendent of Documents.
Prices of new books are listed in the first FEDERAL REGISTER issue of each
week.
========================================================================
[[Page 49153]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. NM326; Special Conditions No. 25-295-SC]
Special Conditions: Boeing Model 777 Series Airplanes; Side-
Facing Single-Occupant Seats Equipped With Inflatable Lapbelts
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
-----------------------------------------------------------------------
SUMMARY: These special conditions are issued for the Boeing Model 777
series airplanes. This airplane will have a novel or unusual design
feature associated with side-facing single-occupant seats equipped with
inflatable lapbelts. The applicable airworthiness regulations do not
contain adequate or appropriate safety standards for these design
features. These special conditions contain the additional safety
standards the Administrator considers necessary to establish a level of
safety equivalent to that established by the existing airworthiness
standards.
DATES: The effective date of these special conditions is August 9,
2005. Send your comments on or before October 7, 2005.
ADDRESSES: Comments on these special conditions may be mailed in
duplicate to: Federal Aviation Administration, Transport Airplane
Directorate, Attn: Rules Docket (ANM-113), Docket No. NM326, 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. NM326. 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: Alan Sinclair, FAA, Airframe/Cabin
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 227-2195, facsimile (425) 227-1232.
SUPPLEMENTARY INFORMATION: The FAA has determined that notice and
opportunity for prior public comment hereon are impracticable because
these procedures would significantly delay issuance of the approval
design and thus delivery of the affected aircraft. In addition, the
substance of these special conditions has been subject to the public
comment process in several prior instances with no substantive comments
received. The FAA therefore finds that good cause exists for making
these special conditions effective upon issuance.
Comments Invited
We invite 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 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
these special conditions in light of the comments we receive.
If you want the FAA to acknowledge receipt of your comments on
these special conditions, 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 July 26, 2004, Boeing Commercial Airplanes, P.O. Box 3707,
Seattle, Washington 98124, applied for a type certificate design change
to install single-occupant side-facing seats equipped with inflatable
lapbelts in Boeing Model 777 series airplanes. The Model 777 series
airplane is a swept-wing, conventional-tail, twin-engine, turbofan-
powered transport category airplane.
Type Certification Basis
Under the provisions of 14 CFR 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: 14 CFR part 25, 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 Sec. Sec. 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 14 CFR part 34 and the noise
certification requirements of 14 CFR part 36.
Special conditions, as appropriate, are issued in accordance with
14 CFR 11.19 after public notice, as required by Sec. 11.38, and
become part of the type certification basis in accordance with Sec.
21.101(b)(2).
[[Page 49154]]
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 novel or
unusual design feature, the special conditions would also apply to the
other model under the provisions of Sec. 21.101(a)(1).
Novel or Unusual Design Features
The Boeing Model 777 offers interior arrangements which include
single-occupant side-facing seat installations. These arrangements
include a unique ``pod'' style of side-facing seats that use inflatable
lapbelts instead of standard belts for occupant restraint. 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 established.
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 supplement part 25 and, more specifically, supplement
Sec. Sec. 25.562 and 25.785. The requirements contained in these
special conditions consist of both test conditions and injury pass/fail
criteria.
Discussion
Section 25.785(b), ``Seats, berths, safety belts, and harnesses,''
requires that ``each seat * * * at each station designated as
occupiable during takeoff and landing must be designed so that a person
making proper use of these facilities 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, ``Emergency
landing dynamic conditions,'' requires dynamic testing of all seats
occupied during takeoff and landing. The relative forces and injury
mechanisms affecting the occupants of side-facing seats during an
emergency landing are different from those of standard forward- or aft-
facing seats, or seats equipped with conventional restraint systems.
Side-facing Seats: Amendment 25-64, which adopted Sec. 25.562,
enhances occupant protection during emergency landing conditions.
Although the rule was written with forward- and aft-facing seats in
mind, the orientation of the seat does not change the relevant test
conditions, and the rule applies to all seats regardless of
orientation.
The dynamic test conditions included in Sec. 25.562 are directly
applicable to side-facing seats. However, for injury pass/fail
criteria, the orientation of the seat may be significant. For forward-,
aft-, and side-facing seats the injury criteria are currently limited
to head, spine, and femur loads. The head and lumbar loads are critical
but the femur load is not critical. For a side-facing seat, additional
injury parameters may be identified and evaluation of those parameters
would be necessary to provide an acceptable level of safety.
When evaluating side-facing seats the following should be taken
into consideration:
1. The isolation of one occupant from another. Occupants should not
rely on impact with other occupants to provide energy absorption; body-
to-body impacts are unacceptable.
2. The restraint system and the retention of occupants in the seat.
Addressing this concern may necessitate providing a means of restraint
for the lower limbs as well as the torso. Failure to limit the forward
(in the airplane's coordinate system) travel of the lower limbs may
cause the occupant to come out of the restraint system or produce
severe injuries due to the resulting position of the restraint system
and/or twisting (torsional load) of the lower lumber spinal column.
3. The load limit in the torso in the lateral direction. Human
tolerance for side-facing seats differs from that for forward- or aft-
facing seats.
The automotive industry has developed test procedures and occupant
injury criteria appropriate for side impact conditions. The criteria
includes limiting lateral pelvic accelerations and using the ``Thoracic
Trauma Index,'' which is defined in 49 CFR 571.214. Use of the Side
Impact Dummy (SID) identified in 49 CFR part 572, subpart F, rather
than the Hybrid II dummy identified in 49 CFR part 572, subpart B, is
required to evaluate these parameters. The Hybrid II dummy is used in
the current Sec. 25.562 test. Testing with a SID is the best means
available to assess the injury potential of a sideward impact
condition. Such an evaluation is considered necessary to provide an
acceptable level of safety for side-facing seats.
The side-facing seat special conditions have been determined to
result in a level of safety equivalent to that provided by the injury
pass/fail criteria in Sec. 25.562 for forward- or aft-facing seats.
Inflatable Lapbelts: From the standpoint of a passenger safety
system, the inflatable lapbelt is unique because it is both an active
and entirely autonomous device. While the automotive industry has good
experience with airbags, which are similar to inflatable lapbelts, the
conditions of use and reliance on the inflatable lapbelt as the sole
means of injury protection in an airplane are quite different. In
automobile installations, the airbag is a supplemental system that
works in conjunction with an upper torso restraint. In addition, an
automobile crash is more definable and is typically shorter in
duration, which can simplify the activation logic of the airbag. The
airplane operating environment is also quite different from automobiles
and includes the potential for greater wear and tear and unanticipated
abuse conditions (due to galley loading, passenger baggage, etc.).
Airplanes also operate where exposure to high intensity electromagnetic
fields could affect the inflatable lapbelt activation system.
The lapbelt special conditions can be characterized as addressing
either the safety performance of the inflatable lapbelt activation
system, or the system's integrity against inadvertent activation.
Because a crash requiring the use of inflatable lapbelts is a
relatively rare event, and the consequences of an inadvertent
activation are potentially quite severe, these latter requirements are
more rigorous from a design standpoint.
Applicability
As discussed above, these special conditions are applicable to the
Boeing Model 777. Should the Boeing Company 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 under the provisions of Sec. 21.101.
Conclusion
This action affects only certain novel or unusual design features
on the Boeing Model 777 airplane. 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.
Under standard practice, the effective date of final special
conditions would be 30 days after the date of publication in the
Federal Register; however, as the certification date for the Boeing
Model 777 series airplanes is imminent, the
[[Page 49155]]
FAA finds that good cause exists to make these special conditions
effective upon issuance.
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 Special Conditions
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 the Boeing Model 777 airplane.
In addition to the airworthiness standards of Sec. Sec. 25.562 and
25.785, the minimum acceptable standards for dynamic certification of
Boeing Model 777 single-occupant side-facing seats are as follows:
Additional 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 only required for
head contact with the seat and/or adjacent structures.
(b) Body-to-Wall/Furnishing Contact: Under the load condition
defined in Sec. 25.562(b)(2), the seat must be installed immediately
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: Under the load condition defined in Sec.
25.562(b)(2), Thoracic Trauma Index (TTI) injury criterion must be
substantiated by dynamic test or by rational analysis based on previous
test(s) of a similar seat installation. Testing must be conducted with
a Side Impact Dummy (SID), as defined by Title 49 Code of Federal
Regulations (CFR) part 572, Subpart F, or its equivalent. The TTI must
be less than 85, as defined in 49 CFR part 572, Subpart F. The SID TTI
data must be processed as defined in Federal Motor Vehicle Safety
Standard (FMVSS) part 571.214, section S6.13.5.
(d) Pelvis: Under the load condition defined in Sec. 25.562(b)(2),
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 strap tension loads must not exceed 2,000
pounds.
(f) Neck Injury Criteria: The seating system must protect the
occupant from experiencing serious neck injury.
Inflatable Lapbelt Conditions
(a) If inflatable lapbelts are used as the means of occupant
restraint on single place side-facing seats, the requirements of
existing Special Conditions 25-04-03-SC (1-14), ``Boeing Model 777
Series Airplanes; Seats with Inflatable Lapbelts'' are incorporated by
reference except for special conditions 1 and 3, which are replaced by
(b) and (c) below.
(b) 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, neck,
thoracic, and pelvic lateral acceleration injury from body-to-wall/
furnishing contact. The means of protection must take into
consideration a range of stature from two-year-old child to ninety-
fifth percentile male. The inflatable lapbelt must provide a consistent
approach to energy absorption throughout the range. In addition, the
following situations must be considered:
1. The seat occupant is holding an infant.
2. The seat occupant is a child in a child restraint device.
3. The seat occupant is a child not using a child restraint device.
4. The seat occupant is a pregnant woman.
(c) 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 injury protection.
Note: The existing means of controlling HIC, TTI and pelvic
lateral acceleration result in a progressive reduction of injury
severity for impact conditions less than the maximum specified by
the requirements. However, airbag technology involves a step change
in protection for impacts below and above that at which the airbag
deploys. This could result in one or more of the injury criteria
being higher at an intermediate impact condition than that resulting
from the maximum. The step change in injury protection is
acceptable, provided that the injury criteria values for any
intermediate impact (whether or not the inflatable lapbelt delays)
do not exceed the maximum allowed by the requirements.
Additional Test Requirements
(a) One longitudinal test with the SID Anthropomorphic Test Dummy
(ATD), undeformed floor, no yaw, and with all lateral structural
supports (armrests/walls).
Pass/fail injury assessments: The TTI and pelvic acceleration.
(b) One longitudinal test with the Hybrid II ATD, deformed floor,
with 10 degrees yaw, and with all lateral structural supports
(armrests/walls).
Pass/fail injury assessments: The HIC; upper torso restraint load,
restraint system retention, and pelvic acceleration.
(c) Vertical (14 G's) test is to be conducted with modified Hybrid
II ATDs with existing pass/fail criteria.
Note: It must be demonstrated that seats installed on plinths or
pallets meet all applicable requirements. Compliance with the
guidance contained in FAA Policy Memorandum PS-ANM-100-2000-00123,
dated February 2, 2000, titled ``Guidance for Demonstrating
Compliance with Seat Dynamic Testing for Plinths and Pallets'' will
be acceptable to the FAA.
Issued in Renton, Washington, on August 9, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 05-16745 Filed 8-22-05; 8:45 am]
BILLING CODE 4910-13-P