[Federal Register Volume 81, Number 135 (Thursday, July 14, 2016)]
[Rules and Regulations]
[Pages 45405-45407]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2016-16639]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 25
[Docket No. FAA-2016-6136; Special Conditions No. 25-620-SC]
Special Conditions: American Airlines, Boeing 777-200 Series
Airplanes; Dynamic Test Requirements for Single-Occupant Oblique (Side-
Facing) Seats Equipped With Inflatable Lapbelts
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions; request for comments.
-----------------------------------------------------------------------
SUMMARY: These special conditions are issued for the Boeing 777-200
series airplane. This airplane, as modified by American Airlines, will
have novel or unusual design features when compared to the state of
technology envisioned in the airworthiness standards for transport-
category airplanes. These airplanes will include single-occupant
oblique seats with inflatable lapbelts 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 American Airlines on July 14, 2016.
We must receive your comments by August 29, 2016.
ADDRESSES: Send comments identified by docket number FAA-2016-6136
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: John Shelden, FAA, Airframe and Cabin
Safety Branch, ANM-115, Transport Airplane Directorate, Aircraft
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone 425-227-2785; 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
airplanes.
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 November 3, 2015, American Airlines applied for a supplemental
type certificate for installation of TSO-C39c-approved B/E Aerospace
Super Diamond model oblique business-class passenger seats in Boeing
Model 777-200 series airplanes. The Model 777-200 airplane, approved
under type certificate no. T00001SE, is a transport-category, twin-
engine jet airplane with a maximum capacity of 440 passengers and a
maximum takeoff weight of 535,000 lbs.
Type Certification Basis
Under the provisions of Title 14, Code of Federal Regulations (14
CFR) 21.101, American Airlines must show that the Boeing Model 777-200
series airplane, as changed, continues to meet the applicable
provisions of the regulations listed in type certificate no. T00001SE,
or the applicable regulations in effect on
[[Page 45406]]
the date of application for the change, except for earlier amendments
as agreed upon by the FAA.
In addition, the certification basis includes certain special
conditions, exemptions, or later amended sections of the applicable
part that are not relevant to these special conditions.
If the Administrator finds that the applicable airworthiness
regulations (i.e., 14 CFR part 25) do not contain adequate or
appropriate safety standards for the Boeing Model 777-200 series
airplane because of a novel or unusual design feature, 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 applicant apply for a supplemental type
certificate to modify any other model included on the same type
certificate 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 777-200 series 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 Boeing Model 777-200 series airplane will incorporate the
following novel or unusual design features: Single-occupant oblique
(side-facing) seats with inflatable lapbelts.
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 Sec. 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. However, 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.
These seats will be installed at a maximum angle of 30 degrees to
the aircraft centerline and will include an inflatable lapbelt
restraint system for occupant restraint and injury protection.
The airbag in the inflatable lapbelt is designed to limit occupant
forward excursion in the event of an emergency landing condition. This
reduces the potential for head injury, thereby reducing the Head Injury
Criteria (HIC) measurement. The use of an inflatable airbag in this
fashion is novel for commercial aviation.
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.
Applicability
As discussed above, these special conditions are applicable to the
Boeing Model 777-200 series airplane. Should American Airlines apply at
a later date for a supplemental type certificate to modify any other
model included on type certificate no. T00001SE, to incorporate 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 airplane. It is not a rule of general
applicability and affects only the applicant who applied to the FAA for
approval of these features on the airplane.
The substance of these special conditions has been subject to the
public-comment process with no substantive comments received. 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, 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.
[[Page 45407]]
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 777-200 series airplanes
modified by American Airlines.
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
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 (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) 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,'' V. Gowdy, et al. (1999). 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: In addition to these special conditions, the inflatable
lapbelts must meet the criteria of special conditions no. 25-187A-SC,
titled, ``Boeing Model 777 Series Airplanes; Seats with Inflatable
Lapbelts.''
Issued in Renton, Washington, on July 7, 2016.
Michael Kaszycki,
Assistant Manager, Transport Airplane Directorate, Aircraft
Certification Service.
[FR Doc. 2016-16639 Filed 7-13-16; 8:45 am]
BILLING CODE 4910-13-P