[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