[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:
    <bullet> Federal eRegulations Portal: Go to http://www.regulations.gov/ and follow the online instructions for sending 
your comments electronically.
    <bullet> 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.
    <bullet> 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.
    <bullet> 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 <a href="/cdn-cgi/l/email-protection#6f25000701413c070a030b0a012f090e0e41080019"><span class="__cf_email__" data-cfemail="4f05202721611c272a232b2a210f292e2e61282039">[email protected]</span></a>.

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 N<INF>ij</INF> (calculated in accordance with 49 CFR 
571.208) must be below 1.0, where N<INF>ij</INF> = F<INF>z</INF>/
F<INF>zc</INF> + M<INF>y</INF>/M<INF>yc</INF>, and N<INF>ij</INF> 
critical values are:

    i. F<INF>zc</INF> = 1,530 lb for tension
    ii. F<INF>zc</INF> = 1,385 lb for compression
    iii. M<INF>yc</INF> = 229 lb-ft in flexion
    iv. M<INF>yc</INF> = 100 lb-ft in extension

    b. In addition, peak F<INF>z</INF> 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 (F<INF>z</INF>) 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


</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>