Document ID: FAA-2016-5909-0001
Agency: faa
Document Type: Rule
Title: Special Conditions: The Boeing Co. Model 787-9 Series Airplane; Dynamic Test Requirements for Single-Occupant Oblique (Side-Facing) Seats with Inflatable and 3-Point Restraint Systems
Posted Date: 2016-08-03T04:00Z

[Federal Register Volume 81, Number 149 (Wednesday, August 3, 2016)]
[Rules and Regulations]
[Pages 51081-51084]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-18449]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

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

Special Conditions: The Boeing Company Model 787-9 Series 
Airplane; Dynamic Test Requirements for Single-Occupant Oblique (Side-
Facing) Seats With Inflatable and 3-Point Restraint Systems

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for The Boeing Company 
(Boeing) Model 787-9 series airplane. This airplane, as modified by 
Boeing, 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 single-occupant 
oblique (side-facing) seats with inflatable and 3-point restraint 
systems requiring dynamic testing. The applicable airworthiness 
regulations do not contain adequate or appropriate safety standards for 
these design features. These 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: This action is effective on Boeing on August 3, 2016. We must 
receive your comments by September 19, 2016.

ADDRESSES: Send comments identified by docket number FAA-2016-5909 
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 Web site, 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), as well as at http://DocketsInfo.dot.gov/ gov/.
    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: Jeff Gardlin, FAA, Airframe and Cabin 
Safety branch, ANM-115, Transport

[[Page 51082]]

Airplane Directorate, Aircraft Certification Service, 1601 Lind Avenue 
SW., Renton, Washington 98057-3356; telephone 425-227-2136; facsimile 
425-227-1320.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and 
opportunity for prior public comment on, these special conditions is 
impracticable because these procedures would significantly delay 
issuance of the design approval and thus delivery of the affected 
airplane.
    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 
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 January 29, 2016, Boeing applied for a change to type 
certificate no. T00021SE to install single-occupant oblique (side-
facing) seats with inflatable and 3-point restraint systems in the 
Model 787-9 airplane.
    This airplane is a twin-engine transport-category airplane. It has 
a 420-passenger capacity and a maximum takeoff weight of 553,000 lbs.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR), 21.101, Boeing must show that the Model 787-9 airplane meets 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 Model 787-9 airplane 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 Model 787-9 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 Model 787-9 airplane will incorporate the following novel or 
unusual design features:
    Single-occupant oblique (side-facing) seats with inflatable and 3-
point restraint systems requiring dynamic testing.

Discussion

    Amendment 25-15 to part 25, dated October 24, 1967, introduced the 
subject of side-facing seats and a requirement that each occupant in a 
side-facing seat must be protected from head injury by a safety belt 
and a cushioned rest that will support the arms, shoulders, head, and 
spine.
    Subsequently, Amendment 25-20, dated April 23, 1969, clarified the 
definition of side-facing seats to require that each occupant of a seat 
that is positioned at more than an 18-degree angle to the vertical 
plane containing the airplane centerline must be protected from head 
injury by a safety belt and an energy-absorbing rest that supports the 
arms, shoulders, head, and spine; or by a safety belt and shoulder 
harness that prevents the head from contacting injurious objects. The 
FAA concluded that a maximum 18-degree angle would provide an adequate 
level of safety based on tests that were performed at the time, and 
thus adopted that standard.
    Amendment 25-64, dated June 16, 1988, revised the emergency-landing 
conditions that must be considered in the design of the airplane. It 
revised the static-load conditions in 14 CFR 25.561 and added a new 
Sec.  25.562, requiring dynamic testing for all seats approved for 
occupancy during takeoff and landing. The intent was to provide an 
improved level of safety for occupants on transport-category airplanes. 
Because most seating on transport-category airplanes is forward-facing, 
the pass/fail criteria developed in Amendment 25-64 focused primarily 
on forward-facing seats. Therefore, the testing specified in the rule 
did not provide a complete measure of occupant injury in seats that are 
not forward-facing; although Sec.  25.785 does require that occupants 
of all seats that are occupied during taxi, takeoff, and landing not 
suffer serious injury as a result of the inertia forces specified in 
Sec. Sec.  25.561 and 25.562.
    To address recent research findings and accommodate commercial 
demand, the FAA developed a methodology to address all fully side-
facing seats (i.e., seats oriented in the airplane with the occupant 
facing 90-degrees to the direction of airplane travel) and has 
documented those requirements in a set of proposed new special 
conditions. The FAA issued policy statement PS-ANM-25-03-R1 on November 
12, 2012, titled, ``Technical Criteria for Approving Side-Facing 
Seats,'' which conveys the injury criteria to be used in the special 
conditions. Some of those criteria are applicable to oblique seats but 
others are not, because the motion of an occupant in an oblique seat is 
different from the motion of an occupant in a fully side-facing seat 
during emergency landing conditions.
    For shallower installation angles, the FAA has granted equivalent 
level of safety (ELOS) findings for oblique seat installations on the 
premise that an occupant's kinematics in an oblique seat during a 
forward impact would result in the body aligning with the impact 
direction. We predicted that the occupant response would be similar to 
an occupant of a forward-facing seat, and would produce a level of 
safety equivalent to that of a forward-facing seat. These ELOS findings 
were subject to many conditions that reflected the injury-evaluation 
criteria and mitigation strategies available at the time of issuance of 
the ELOS. However, review of dynamic test results for many of these 
oblique seat installations raised concerns that the premise was not 
correct. Potential injury mechanisms exist that are unique to oblique 
seats and are not mitigated by the ELOS self-alignment approach even if 
the occupant appears to respond similarly to a forward-facing seat.
    The proposed Model 787 airplane oblique business-class seat 
installations are novel such that the current Model 787 airplane 
certification basis does not adequately address occupant protection 
expectations with regard to the occupant's neck and spine for seat 
configurations that are oriented at an angle greater than 18-degrees 
from the airplane centerline. The FAA has previously issued special 
conditions no. 25-580-SC for the 787, which reflected the best 
available criteria at the time. However, as the FAA continues research 
into the injury mechanisms associated with obliquely oriented seats and 
the means to measure those injuries, the criteria evolve. These special 
conditions

[[Page 51083]]

therefore reflect refinements beyond special conditions no. 25-580-SC, 
and that incorporate the knowledge gained from research. The intent of 
the special conditions is unchanged. These 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.
    Boeing proposes to install on Model 787-9 airplanes 3-point 
restraint systems and airbag devices as a means to protect each 
occupant from serious injury in the event of an emergency landing, as 
required by Sec.  25.562(c)(5). Shoulder harnesses have been widely 
used on attendant seats, flight-deck seats, business jets, and general-
aviation airplanes to reduce occupant head injury in the unlikely event 
of an emergency landing. A passenger-seat 3-point restraint system is 
defined as a safety belt (pelvic restraint), a single-belt shoulder 
harness, and the seat structure associated with the harness attachment 
points. The 3-point restraint system is intended to protect the 
occupant from serious injury, and the means of protection must take 
into consideration a range of occupant stature, ranging from a 2-year 
old child to a 95th percentile male, in addition to the oblique seat 
orientation. The use of 3- point restraint systems on transport-
category airplane passenger seats is rare; however, existing 
regulations provide an adequate safety standard for these 
installations. The FAA has issued advisory material on acceptable means 
of compliance for combined shoulder-harness and safety-belt restraint 
systems, such as the 3-point restraint system.
    Inflatable airbag devices are designed to limit occupant forward 
excursion in the event of an accident. This will reduce the potential 
for head injury, thereby reducing the head injury criteria (HIC) 
measurement. While inflatable airbags are now standard in the 
automotive industry, the use of an inflatable airbag device is novel 
for commercial aviation. Special conditions exist for airbags installed 
on seat belts, known as inflatable lapbelts, which have been installed 
on Boeing passenger seats. The FAA has also issued special conditions 
for structure-mounted airbags on the Model 787-9 that are similar to 
those for inflatable lapbelts, but that account for the differences 
between the two types of airbag installations.

Applicability

    These special conditions are applicable to the following Boeing 
Model 787-9 airplanes: AAL ZB 446 (Project PS15-0762), AMX ZB 676 
(Project PS15-0588), XIA ZB 812 (Project PS16-0060), and JAL ZB 424 
(Project PS15-0723).

Conclusion

    This action affects only certain novel or unusual design features 
on one model of airplanes. It is not a rule of general applicability.
    The substance of these special conditions has been subject to the 
public-comment process in several prior instances with no substantive 
comments received. Therefore, because a delay would significantly 
affect the certification of the airplane, 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.

    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 Boeing Model 787-9 airplanes.
    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 
anthropomorphic test device (ATD) has no apparent contact with the 
seat/structure but has contact with an airbag, a 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. interior wall or 
furnishings) that does not provide a homogenous contact surface for the 
expected range of occupants and yaw angles, then additional analysis 
and/or tests may be required to demonstrate that the injury criteria 
are met for the area which an occupant could contact. For example, if 
an airbag device is present, different yaw angles could result in 
different airbag-device performance, and additional analysis or 
separate tests may be necessary to evaluate performance.

3. Neck Injury Criteria

    The seating system must protect the occupant from experiencing 
serious neck injury. If an airbag device is present, 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 = 1530 lb for tension
ii. Fzc = 1385 lb for compression
iii. Myc = 229 lb-ft in flexion
iv. Myc = 100 lb-ft in extension

    b. In addition, peak upper-neck Fz must be below 937 lb 
of tension and 899 lb of 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 instrumentation specified in 
49 CFR part 572, subpart E, filtered in accordance with SAE 
International (SAE) J211-1.
    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

[[Page 51084]]

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. 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.

Structure-Mounted Airbag and Inflatable Lapbelt Special Conditions

    When present, the structure-mounted airbag device must meet special 
conditions no. 25-605-SC, ``Boeing Model 787-9 Airplane; Structure-
Mounted Airbags.'' When present, the inflatable lapbelt(s) must meet 
special conditions no. 25-431-SC, ``Boeing Model 787 Series Airplanes; 
Seats with Inflatable Lapbelts.''

    Note:  As indicated in the special conditions above, airbags and 
inflatable lapbelts must be shown to not affect emergency-egress 
capabilities in the main aisle, cross-aisle, and passageway.

    Issued in Renton, Washington, on July 27, 2016.
Victor Wicklund,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-18449 Filed 8-2-16; 8:45 am]
 BILLING CODE 4910-13-P