Special Conditions: The Boeing Company (Boeing), Model 777 Series Airplanes; Dynamic Test Requirements for Single Occupant Oblique Seats, With or Without Airbag Devices or 3-Point Restraints, 46101-46103 [2018-19752]
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Federal Register / Vol. 83, No. 177 / Wednesday, September 12, 2018 / Rules and Regulations
5. Pelvis Criteria
DEPARTMENT OF TRANSPORTATION
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.
Federal Aviation Administration
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 mostcritical 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]
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BILLING CODE 4910–13–P
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14 CFR Part 25
[Docket No. FAA–2016–4136; Special
Conditions No. 25–621A–SC]
Special Conditions: The Boeing
Company (Boeing), Model 777 Series
Airplanes; Dynamic Test Requirements
for Single Occupant Oblique Seats,
With or Without Airbag Devices or 3Point Restraints
Federal Aviation
Administration (FAA), DOT.
ACTION: Amended final special
conditions; request for comments.
AGENCY:
These amended special
conditions are issued for the Boeing
Model 777 series airplanes. This
amendment states that the Boeing
Model 777 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 passenger seats
equipped with or without airbag devices
or 3-point restraints. The applicable
airworthiness regulations do not contain
adequate or appropriate safety standards
for this design feature. 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 The
Boeing Company on September 12,
2018. Send comments on or before
October 29, 2018.
ADDRESSES: Send comments identified
by Docket No. FAA–2016–4136 using
any of the following methods:
• Federal eRegulations Portal: Go to
https://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
SUMMARY:
PO 00000
Frm 00033
Fmt 4700
Sfmt 4700
46101
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 https://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
https://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 John.Shelden@faa.gov.
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 an amendment to Type
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46102
Federal Register / Vol. 83, No. 177 / Wednesday, September 12, 2018 / Rules and Regulations
Certificate No. T00001SE for the
installation of oblique (side-facing)
passenger seats with or without airbag
devices or 3-point restraints in the
Boeing Model 777 series airplanes. The
Boeing Model 777 series airplanes are
twin-engine, transport category
airplanes with a maximum certified
passenger capacity of up to 550 and a
maximum takeoff weight of
approximately 775,000 lbs.
daltland on DSKBBV9HB2PROD with RULES
Type Certification Basis
Under the provisions of title 14, Code
of Federal Regulations (14 CFR) 21.101,
Boeing must show that the Model 777
series airplanes meet the applicable
provisions of the regulations listed in
Type Certificate No. T00001SE, 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 777 series
airplanes because of novel or unusual
design features, special conditions are
prescribed under the provisions of
§ 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 § 21.101.
In addition to the applicable
airworthiness regulations and special
conditions, the Boeing Model 777 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 § 11.38, and they become part of
the type certification basis under
§ 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
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16:01 Sep 11, 2018
Jkt 244001
seating configuration is also beyond the
limits of current acceptable equivalentlevel-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 obliqueangled 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
§§ 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 777
series airplanes business-class seat
installation is novel such that the
current Boeing Model 777 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. 25–569–SC for
Model 777–300ER airplanes on
September 25, 2014, and special
conditions No. 25–621–SC for certain
Model 777–300ER airplanes on August
3rd, 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
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furniture that introduces occupant
alignment/loading concerns with or
without the installation of a 3-point or
airbag restraint system, or both. Ongoing 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
25–569–SC and 25–621–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
§ 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 777
series airplanes.
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Federal Register / Vol. 83, No. 177 / Wednesday, September 12, 2018 / Rules and Regulations
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 777 series airplane. 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
series of airplanes. It is not a rule of
general applicability.
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
777 series airplanes.
Side-Facing Seats Special Conditions
In addition to the requirements of
§ 25.562:
1. Head Injury Criteria (HIC)
Compliance with § 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 HIC
unlimited score in excess of 1,000 is
acceptable, provided the HIC15 score for
that contact (calculated in accordance
with 49 CFR 571.208) is less than 700.
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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 tests may be
required to demonstrate that the injury
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16:01 Sep 11, 2018
Jkt 244001
criteria are met for the area which an
occupant could contact. For example,
different yaw angles could result in
different airbag device performance,
then additional analysis or separate tests
may be necessary to evaluate
performance.
6. Femur Criteria
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
a reason to also consider that the neckinjury 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:
7. ATD and Test Conditions
i. Fzc = 1,530 lbs for tension
ii. Fzc = 1,385 lbs 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 lbs. in tension and
899 lbs. 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 1,200 lbs.
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 20 g
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 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.
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46103
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.
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 mostcritical yaw cases for injury, and with
all lateral structural supports (e.g.,
armrests or walls) installed.
Issued in Des Moines, Washington, on
September 5, 2018.
Victor Wicklund,
Manager, Transport Standards Branch, Policy
and Innovation Division, Aircraft
Certification Service.
[FR Doc. 2018–19752 Filed 9–11–18; 8:45 am]
BILLING CODE 4910–13–P
DEPARTMENT OF COMMERCE
Bureau of Industry and Security
15 CFR Part 744
[Docket No. 180718671–8671–01]
RIN 0694–AH57
Addition of Certain Entities to the
Entity List, Revision of Entries on the
Entity List and Removal of Certain
Entities From the Entity List
Correction
In rule document 2018–18766
beginning on page 44821 in the issue of
Tuesday, September 4, 2018, make the
following correction:
1. On page 44824, in the third
column, amendatory instruction number
2e is corrected to read as follows:
‘‘2. * * *
e. Under Russia,
i. By removing the entity ‘‘Joint Stock
Company Mikron’’;
ii. By adding in alphabetical order
two entities ‘‘Joint Stock Company (JSC)
NIIME’’ and ‘‘PJSC Mikron’’;
2. On page 44825, in the table, under
the country heading for Hong Kong, the
Joinus Freight Systems entry should
read as follows:
*
*
*
*
*
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]]>Agencies
[Federal Register Volume 83, Number 177 (Wednesday, September 12, 2018)]
[Rules and Regulations]
[Pages 46101-46103]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-19752]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2016-4136; Special Conditions No. 25-621A-SC]
Special Conditions: The Boeing Company (Boeing), Model 777 Series
Airplanes; Dynamic Test Requirements for Single Occupant Oblique 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 777 series airplanes. This amendment states that the Boeing Model
777 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 passenger seats
equipped with or without airbag devices or 3-point restraints. The
applicable airworthiness regulations do not contain adequate or
appropriate safety standards for this design feature. 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 The Boeing Company on September 12,
2018. Send comments on or before October 29, 2018.
ADDRESSES: Send comments identified by Docket No. FAA-2016-4136 using
any of the following methods:
Federal eRegulations Portal: Go to https://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 https://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
https://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 [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 November 22, 2017, Boeing applied for an amendment to Type
[[Page 46102]]
Certificate No. T00001SE for the installation of oblique (side-facing)
passenger seats with or without airbag devices or 3-point restraints in
the Boeing Model 777 series airplanes. The Boeing Model 777 series
airplanes are twin-engine, transport category airplanes with a maximum
certified passenger capacity of up to 550 and a maximum takeoff weight
of approximately 775,000 lbs.
Type Certification Basis
Under the provisions of title 14, Code of Federal Regulations (14
CFR) 21.101, Boeing must show that the Model 777 series airplanes meet
the applicable provisions of the regulations listed in Type Certificate
No. T00001SE, 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 777 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 777 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 777 series airplanes business-class seat
installation is novel such that the current Boeing Model 777 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. 25-569-SC for Model
777-300ER airplanes on September 25, 2014, and special conditions No.
25-621-SC for certain Model 777-300ER airplanes on August 3rd, 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 25-569-SC
and 25-621-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 777 series
airplanes.
[[Page 46103]]
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 777 series airplane. 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 series of airplanes. It is not a rule of general
applicability.
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 777 series airplanes.
Side-Facing Seats Special Conditions
In addition to the requirements of Sec. 25.562:
1. Head Injury Criteria (HIC)
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 HIC unlimited score in excess of 1,000 is acceptable,
provided the HIC15 score for that contact (calculated in accordance
with 49 CFR 571.208) 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 tests may be required to demonstrate that the injury criteria are
met for the area which an occupant could contact. For example,
different yaw angles could result in different airbag device
performance, then 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. The assessment of neck injury must be conducted
with the airbag device activated, unless there is a 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 lbs for tension
ii. Fzc = 1,385 lbs 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
lbs. in tension and 899 lbs. 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 1,200
lbs.
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 20 g 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 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.
Issued in Des Moines, Washington, on September 5, 2018.
Victor Wicklund,
Manager, Transport Standards Branch, Policy and Innovation Division,
Aircraft Certification Service.
[FR Doc. 2018-19752 Filed 9-11-18; 8:45 am]
BILLING CODE 4910-13-P
