[Federal Register Volume 83, Number 177 (Wednesday, September 12, 2018)]
[Rules and Regulations]
[Pages 46098-46101]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-19753]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2016-5909; Special Conditions No. 25-626A-SC]


Special Conditions: The Boeing Company (Boeing), Model 787-8, 
787-9, and 787-10 Series Airplanes; 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.

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SUMMARY: These amended special conditions are issued for the Boeing 
Model 787-8, 787-9, and 787-10 series airplanes. This amendment states 
that the Boeing Model 787-8, 787-9, and 787-10 series airplanes 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. 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 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 12, 2018. Send 
comments on or before October 29, 2018.

ADDRESSES: Send comments identified by Docket No. FAA-2016-5909 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

[[Page 46099]]

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, 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#4e04212620601d262b222a2b200e282f2f60292138"><span class="__cf_email__" data-cfemail="1e54717670304d767b727a7b705e787f7f30797168">[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 November 22, 2017, Boeing applied for a change to Type 
Certificate No. T00021SE for the installation of oblique (side-facing) 
passenger seats with or without airbag devices or 3-point restraints in 
the Boeing Model 787-8, 787-9, and 787-10 series airplanes. The Boeing 
Model 787-8, 787-9, and 787-10 series airplanes are twin-engine, 
transport category airplanes with a maximum certified passenger 
capacity of up to 440, and a maximum takeoff weight of approximately 
476,000 lbs.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.101, Boeing must show that the Model 787-8, 787-9, and 787-10 
series airplanes, as changed, continue to meet the applicable 
provisions of the regulations listed in Type Certificate No. T00021SE 
or the applicable regulations in effect on the date of application for 
the change, except for earlier amendments as agreed upon by the FAA.
    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 Boeing Model 787-8, 787-9, and 
787-10 series airplanes because of novel or unusual design features, 
special conditions are prescribed under the provisions of 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 787-8, 787-9, and 787-10 series airplanes 
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 is also 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 policy 
statement PS-AIR-25-27, to define injury criteria for oblique (side-
facing) seats.
    The proposed Boeing Model 787-8, 787-9, and 787-10 series airplanes 
business-class seat installation is novel such that the current Boeing 
Model 787-8, 787-9, and 787-10 series airplanes 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. The FAA issued special conditions 
No. 25-580-SC for Model 787-9 airplanes on April 14, 2015, and special 
conditions No. 25-626-SC for certain Model 787-9 airplanes on July 27, 
2016. These special conditions contained injury criteria for oblique 
seats based on the best knowledge the FAA had at the time. These 
special conditions for oblique 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/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 (side-
facing) seat installations. These updated special conditions further 
address potential injuries to the occupant's neck and spine. As a 
result, these special conditions replace special conditions 25-580-SC 
and 25-626-SC.
    FAA-sponsored research has found that an un-restrained flailing of 
the upper torso, even when the pelvis and

[[Page 46100]]

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 787-8, 
787-9, and 787-10 series airplanes.
    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 787-8, 787-9, and 787-10 series airplanes. Should Boeing 
apply at a later date for a change to the type certificate to include 
another model incorporating the same novel or unusual design feature, 
these special conditions would apply to that 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 Boeing Boeing Model 787-8, 787-9, and 
787-10 series airplanes.

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 1,200 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 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.

[[Page 46101]]

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 787-8, 
787-9 and 787-10 series airplanes.

    Issued in Des Moines, Washington, on September 5, 2018.
Victor Wicklund,
Manager, Transport Standards Branch, Policy and Innovation Division, 
Aircraft Certification Service.
[FR Doc. 2018-19753 Filed 9-11-18; 8:45 am]
 BILLING CODE 4910-13-P


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