[Federal Register Volume 83, Number 172 (Wednesday, September 5, 2018)]
[Rules and Regulations]
[Pages 45034-45037]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-19216]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2015-0309; Special Conditions No. 25-594A-SC]
Special Conditions: The Boeing Company (Boeing) Model 747-8
Airplane, Dynamic Test Requirements for Single-Occupant, Oblique (Side-
Facing) Seats, With or Without Airbag Devices or 3-Point Restraints
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Amended final special conditions; request for comments.
-----------------------------------------------------------------------
SUMMARY: These amended special conditions are issued for the Boeing
Model 747-8 airplane. This amendment states that the Boeing Model 747-8
airplane oblique (side-facing) seats may be installed at an angle of 18
to 45 degrees to the airplane centerline and may include a 3-point or
airbag restraint system, or both, for occupant restraint and injury
protection. Additionally, this amendment changes paragraphs 4 through 8
of the special conditions section. 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. These design features are oblique (side-facing) single-
occupant seats equipped with or without airbag devices or 3-point
restraints.
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: This action is effective on Boeing on September 5, 2018. Send
comments on or before October 22, 2018.
ADDRESSES: Send comments identified by Docket No. FAA-2015-0309 using
any of the following methods:
Federal eRegulations Portal: Go to http://www.regulations.gov/ and follow the online instructions for sending
your comments electronically.
Mail: Send comments to Docket Operations, M-30, U.S.
Department of Transportation (DOT), 1200 New Jersey Avenue SE, Room
W12-140, West Building Ground Floor, Washington, DC, 20590-0001.
Hand Delivery or Courier: Take comments to Docket
Operations in Room W12-140 of the West Building Ground Floor at 1200
New Jersey Avenue SE, Washington, DC, between 9 a.m. and 5 p.m., Monday
through Friday, except Federal holidays.
Fax: Fax comments to Docket Operations at 202-493-2251.
Privacy: The FAA will post all comments it receives, without
change, to http://www.regulations.gov/, including any personal
information the commenter provides. Using the search function of the
docket website, anyone can find and read the electronic form of all
comments received into any FAA docket, including the name of the
individual sending the comment (or signing the comment for an
association, business, labor union, etc.). DOT's complete Privacy Act
Statement can be found in the Federal Register published on April 11,
2000 (65 FR 19477-19478).
Docket: Background documents or comments received may be read at
http://www.regulations.gov/ at any time. Follow the online instructions
for accessing the docket or go to Docket Operations in Room W12-140 of
the West Building Ground Floor at 1200 New Jersey Avenue SE,
Washington,
[[Page 45035]]
DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays.
FOR FURTHER INFORMATION CONTACT: John Shelden, Airframe and Cabin
Safety Section, AIR-675, Transport Standards Branch, Policy and
Innovation Division, Aircraft Certification Service, Federal Aviation
Administration, 2200 South 216th Street, Des Moines, Washington 98198;
telephone and fax 206-231-3214; email [email protected].
SUPPLEMENTARY INFORMATION: The substance of these special conditions
has been published in the Federal Register for public comment in
several prior instances with no substantive comments received. The FAA
therefore finds it unnecessary to delay the effective date and finds
that good cause exists for making these special conditions effective
upon publication in the Federal Register.
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 will consider all comments we receive by the closing date for
comments. We may change these special conditions based on the comments
we receive.
Background
On February 3, 2014, Boeing applied for an amendment to Type
Certificate no. A20WE to allow installation of single-occupant, oblique
(side-facing) seats with or without airbag devices or 3-point
restraints in the Boeing Model 747-8 airplanes.
Boeing requested special conditions to allow installation of
oblique business-class passenger seats in the Boeing Model 747-8
airplane. The seating configuration Boeing proposes in Certification
Plan no. 15090, ``Installation of Business Class Zodiac Seats and
Furniture for 747-8 TRX RC076,'' consists of Zodiac Cirrus III model
oblique (side-facing), pod-style, business-class seats (with
surrounding shells and front-row furniture) installed at an angle of up
to 30 degrees to the airplane longitudinal centerline. These seats will
include inflatable restraint (airbag) systems for occupant restraint
and injury protection.
On November 22, 2017, Boeing applied for a change to Type
Certificate No. A20WE for the installation of oblique (side-facing)
passenger seats and surrounding furniture in the Boeing Model 747-8
airplane. These oblique (side-facing) seats may be installed at an
angle of 18 to 45 degrees to the airplane centerline and may include a
3-point or airbag restraint system, or both, for occupant restraint and
injury protection.
The Boeing Model 747-8 airplane is a four-engine, transport
category airplane with a maximum certified passenger capacity of 605,
and a maximum takeoff weight of 987,000 lbs.
Type Certification Basis
Under the provisions of title 14, Code of Federal Regulations (14
CFR) 21.101, Boeing must show that the Model 747-8 airplane meets the
applicable provisions of the regulations listed in Type Certificate no.
A20WE, or the applicable regulations in effect on the date of
application for the change, except for earlier amendments as agreed
upon by the FAA. The regulations listed in the type certificate are
commonly referred to as the ``original type certification basis.'' The
regulations listed in Type Certificate no. A20WE are as follows:
14 CFR part 25, Amendments 25-1 through 25-120, with exceptions
permitted by Sec. 21.101. In addition, the certification basis
includes certain special conditions, exemptions, or later amended
sections of the applicable part that are not relevant to these 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 Boeing Model 747-8 airplanes because
of a novel or unusual design feature, special conditions are prescribed
under Sec. 21.16.
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, these special conditions would also apply to
the other model under Sec. 21.101. In addition to the applicable
airworthiness regulations and special conditions, the Boeing Model 747-
8 airplane 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 14 CFR 11.19, in
accordance with Sec. 11.38, and they become part of the type
certification basis under Sec. 21.101.
Novel or Unusual Design Features
The business-class seating configuration Boeing proposes is novel
or unusual due to the seat installation at 30 degrees to the airplane
centerline, the airbag-system installation, and the seat/occupant
interface with the surrounding furniture that introduces occupant
alignment and loading concerns. The proposed business-class seating
configuration also is beyond the limits of current acceptable
equivalent-level-of-safety findings. These oblique (side-facing) seats
may be installed at an angle of 18 to 45 degrees to the airplane
centerline and may include a 3-point or airbag restraint system, or
both, for occupant restraint and injury protection.
The existing regulations do not provide adequate or appropriate
safety standards for occupants of oblique-angled seats with airbag
systems. 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
The FAA has been conducting and sponsoring research on appropriate
injury criteria for oblique (side-facing) seat installations. However,
the FAA research program is not complete and we may update these
criteria as we obtain further research results. To reflect current
research findings, the FAA issued policy statement PS-ANM-25-03-R1 to
update injury criteria for fully side facing seats, and the policy
statement PS-AIR-25-27, to define injury criteria for oblique (side-
facing) seats.
The proposed Boeing Model 747-8 airplanes business-class seat
installation is novel such that the current Boeing Model 747-8 airplane
certification basis does not adequately address protection of the
occupant's neck and spine for seat configurations that are positioned
at an angle greater than 18 degrees from the airplane centerline. These
special conditions for oblique (side-facing) seat installations do not
adequately address oblique seats, reflecting the current research
results, with or without 3-point or airbag restraint systems.
Therefore, Boeing's proposed configuration will require amended special
conditions.
The installation of passenger seats at angles of 18 to 45 degrees
to the airplane centerline are unique due to the seat/
[[Page 45036]]
occupant interface with the surrounding furniture that introduces
occupant alignment/loading concerns with or without the installation of
a 3-point or airbag restraint system, or both. On-going research has
invalidated previously released special conditions for oblique seat
installations. These updated special conditions further address
potential injuries to the occupant's neck and spine. As a result, this
special condition replaces special condition 25-594-SC.
FAA-sponsored research has found that an un-restrained flailing of
the upper torso, even when the pelvis and torso are nearly aligned, can
produce serious spinal and torso injuries. At lower impact severities,
even with significant misalignment between the torso and pelvis, these
injuries did not occur. Tests with an FAA H-III anthropomorphic test
device (ATD) have identified a level of lumbar spinal tension
corresponding to the no-injury impact severity. This level of tension
is included as a limit in the special conditions. The spine tension
limit selected is conservative with respect to other aviation injury
criteria since it corresponds to a no-injury loading condition.
As noted in the special conditions for each airbag restraint
system, because an airbag restraint system is essentially a single use
device, there is the potential that it could deploy under crash
conditions that are not sufficiently severe as to require head injury
protection from the airbag restraint system. Since an actual crash is
frequently composed of a series of impacts before the airplane comes to
rest, this could render the airbag restraint system useless if a larger
impact follows the initial impact. This situation does not exist with
energy absorbing pads or upper torso restraints, which tend to provide
protection according to the severity of the impact. Therefore, the
installation of the airbag restraint system should be such that the
airbag restraint system will provide protection when it is required,
and will not expend its protection when it is not needed.
Because these airbag restraint systems may or may not activate
during various crash conditions, the injury criteria listed in these
special conditions and in Sec. 25.562 must be met in an event that is
slightly below the activation level of the airbag restraint system. If
an airbag restraint system is included with the oblique seats, the
system must meet the requirements in one of the airbag (inflatable
restraint) special conditions applicable to the Boeing Model 747-8
airplane.
These amended special conditions will provide head injury criteria,
neck injury criteria, spine injury criteria, and body-to-wall contact
criteria. They 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.
Applicability
As discussed above, these special conditions are applicable to the
Boeing Model 747-8 airplanes. Should Boeing apply at a later date for a
change to the type certificates to include another model incorporating
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, these special
conditions would apply to the other model as well.
Conclusion
This action affects only certain novel or unusual design features
on one model airplane. It is not a rule of general applicability.
The substance of these special conditions has been subjected to the
notice and comment period in several prior instances and has been
derived without substantive change from those previously issued. It is
unlikely that prior public comment would result in a significant change
from the substance contained herein. Therefore, because a delay would
significantly affect the certification of the airplane, which is
imminent, the FAA has determined that prior public notice and comment
are unnecessary and impracticable, and good cause exists for adopting
these special conditions upon publication in the Federal Register. The
FAA is requesting comments to allow interested persons to submit views
that may not have been submitted in response to the prior opportunities
for comment described above.
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(f), 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 747-8 airplane.
Side-Facing Seats Special Conditions
In addition to the requirements of Sec. 25.562:
1. Head Injury Criteria:
Compliance with Sec. 25.562(c)(5) is required, except that, if the
ATD has no apparent contact with the seat/structure but has contact
with an airbag, a head-injury criterion (HIC) unlimited score in excess
of 1000 is acceptable, provided the HIC15 score (calculated in
accordance with 49 CFR 571.208) for that contact is less than 700.
2. Body-to-Wall/Furnishing Contact:
If a seat is installed aft of structure (e.g., an interior wall or
furnishing) that does not provide a homogenous contact surface for the
expected range of occupants and yaw angles, then additional analysis
and/or test(s) may be required to demonstrate that the injury criteria
are met for the area that an occupant could contact. For example, if
different yaw angles could result in different airbag performance, then
additional analysis or separate test(s) may be necessary to evaluate
performance.
3. Neck Injury Criteria:
The seating system must protect the occupant from experiencing
serious neck injury. The assessment of neck injury must be conducted
with the airbag device activated, unless there is reason to also
consider that the neck-injury potential would be higher for impacts
below the airbag-device deployment threshold.
a. The Nij (calculated in accordance with 49 CFR
571.208) must be below 1.0, where Nij = Fz/
Fzc + My/Myc, and Nij
critical values are:
i. Fzc = 1,530 lb for tension
ii. Fzc = 1,385 lb for compression
iii. Myc = 229 lb-ft in flexion
iv. Myc = 100 lb-ft in extension
b. In addition, peak Fz must be below 937 lb in tension
and 899 lb in compression.
c. Rotation of the head about its vertical axis, relative to the
torso, is limited to 105 degrees in either direction from forward-
facing.
d. The neck must not impact any surface that would produce
concentrated loading on the neck.
4. Spine and Torso Injury Criteria:
a. The lumbar spine tension (Fz) cannot exceed 1200 lb.
b. Significant concentrated loading on the occupant's spine, in the
area between the pelvis and shoulders during impact, including rebound,
is not acceptable. During this type of contact, the interval for any
rearward (X direction) acceleration exceeding 20g must be less than 3
milliseconds as measured by the thoracic
[[Page 45037]]
instrumentation specified in 49 CFR part 572, subpart E filtered in
accordance with SAE International (SAE) recommended practice J211/1,
``Instrumentation for Impact Test--Part 1--Electronic
Instrumentation.''
c. The occupant must not interact with the armrest or other seat
components in any manner significantly different than would be expected
for a forward-facing seat installation.
5. Pelvis Criteria:
Any part of the load-bearing portion of the bottom of the ATD
pelvis must not translate beyond the edges of the seat bottom seat-
cushion supporting structure.
6. Femur Criteria:
Axial rotation of the upper leg (about the z-axis of the femur per
SAE Recommended Practice J211/1) must be limited to 35 degrees from the
nominal seated position. Evaluation during rebound does not need to be
considered.
7. ATD and Test Conditions:
Longitudinal tests conducted to measure the injury criteria above
must be performed with the FAA Hybrid III ATD, as described in SAE
1999-01-1609, ``A Lumbar Spine Modification to the Hybrid III ATD for
Aircraft Seat Tests.'' The tests must be conducted with an undeformed
floor, at the most-critical yaw cases for injury and with all lateral
structural supports (e.g. armrests or walls) installed.
Note: Boeing must demonstrate that the installation of seats via
plinths or pallets meets all applicable requirements. Compliance with
the guidance contained in policy memorandum PS-ANM-100-2000-00123,
``Guidance for Demonstrating Compliance with Seat Dynamic Testing for
Plinths and Pallets,'' dated February 2, 2000, is acceptable to the
FAA.
8. Inflatable Airbag Restraint Systems Special Conditions:
If inflatable airbag restraint systems are installed, the airbag
systems must meet the requirements in one of the airbag (inflatable
restraint) special conditions applicable to the Boeing Model 747-8
airplane.
Issued in Des Moines, Washington, on August 22, 2018.
Victor Wicklund,
Manager, Transport Standards Branch, Policy and Innovation Division,
Aircraft Certification Service.
[FR Doc. 2018-19216 Filed 9-4-18; 8:45 am]
BILLING CODE 4910-13-P