Document ID: FAA-2016-6136-0001
Agency: faa
Document Type: Rule
Title: Special Conditions: American Airlines, Boeing 777-200 Series Airplanes; Dynamic Test Requirements for Single-Occupant Oblique (Side-Facing) Seats Equipped with Inflatable Lapbelts
Posted Date: 2016-07-14T04:00Z

[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]

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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.

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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