[Federal Register Volume 84, Number 239 (Thursday, December 12, 2019)]
[Rules and Regulations]
[Pages 67828-67830]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-26722]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2019-0851; Special Conditions No. 25-763-SC]


Special Conditions: VT DRB Aviation Consultants, Airbus Model 
A330-300 Airplanes; Dynamic Test Requirements for Single-Occupant, 
Oblique (Side-Facing) Seats With or Without Airbag Devices or 3-Point 
Restraints

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 Airbus Model A330-
300 airplane. This airplane, as modified by VT DRB Aviation Consultants 
(VT DRB), will have novel or unusual design features when compared to 
the state of technology envisioned in the airworthiness standards for 
transport-category airplanes. This design feature is single-occupant, 
oblique (side-facing) seats with 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 VT DRB on December 12, 2019. Send 
comments on or before January 27, 2020.

ADDRESSES: Send comments identified by Docket No. FAA-2019-0851 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 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 
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: Alan Sinclair, 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 206-231-3215; email [email protected].

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 
published in the Federal Register for public comment in several prior 
instances with no substantive comments received. Therefore, the FAA has 
determined that prior public notice and comment are unnecessary, and 
finds that, for the same reason, good cause exists for adopting these 
special conditions upon publication in the Federal Register.

Comments Invited

    The FAA invites 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.
    The FAA will consider all comments received by the closing date for 
comments. The FAA may change these special conditions based on the 
comments received.

Background

    On October 12, 2018, VT DRB applied for a supplemental type 
certificate for oblique (side-facing) single-occupant seats equipped 
with airbag devices or 3-point restraints in Airbus Model A330-300 
airplanes. The Airbus Model A330-300 airplane is a twin-engine, 
transport-category airplane with a maximum takeoff weight of 533,518 
pounds and seating for 297 passengers.

Type Certification Basis

    Under the provisions of title 14, Code of Federal Regulations (14 
CFR) 21.101, VT DRB must show that the Airbus Model A330-300 airplane, 
as changed, continues to meet the applicable provisions of the 
regulations listed in Type Certificate No. A46NM or the applicable 
regulations in effect on the

[[Page 67829]]

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 (e.g., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the Airbus Model A330-300 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 Airbus Model A330-300 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 Airbus Model A330-300 airplane will incorporate the following 
novel or unusual design features:
    Single-occupant, oblique (side-facing) seats with airbag devices or 
3-point restraints.

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 the FAA may update these 
criteria as the FAA obtains further research results. To reflect 
current research findings, the FAA issued policy statement PS-ANM-25-
03-R1, ``Technical Criteria for Approving Side-Facing Seats,'' November 
12, 2012 to update injury criteria for fully side-facing seats, and 
policy statement PS-AIR-25-27, ``Technical Criteria for Approving 
Oblique Seats,'' July 11, 2018 to define injury criteria for oblique 
(side-facing) seats. Refer to these policy statements for definitions 
of variables used in the formulae shown in the conditions of this 
document.
    The installation of these single occupant, oblique (side-facing) 
seats is novel given that the Airbus Model A330-300 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 installation of passenger seats at angles of 18 to 45 degrees 
to the airplane centerline is unusual in transport category airplanes 
due to the seat and occupant interface with the surrounding furniture 
that introduces occupant alignment and loading concerns with or without 
the installation of a 3-point or airbag restraint system, or both. 
These special conditions are necessary to further address these 
potential injuries to the occupant's neck and spine that were not 
contemplated in 14 CFR 25.785.
    The FAA-sponsored research mentioned earlier has found that an 
unrestrained 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 because it 
corresponds to a no-injury loading condition.
    As noted in the special conditions for the airbag restraint system, 
because an airbag restraint system is essentially a single-use device, 
the airbag potentially could deploy under crash conditions that are not 
sufficiently so severe as to require head-injury protection from the 
airbag restraint system. Because 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 the 
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.
    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 
Airbus Model A330-300 airplane as modified by VT DRB. Should VT DRB 
apply at a later date for a supplemental type certificate to modify any 
other model included on Type Certificate No. A46NM to incorporate the 
same novel or unusual design feature, these special conditions would 
apply to that model as well.

Conclusion

    This action affects only a certain novel or unusual design feature 
on one model 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.

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 Airbus Model A330-300 airplanes as 
modified by VT DRB.
    In addition to the requirements of Sec.  25.562, passenger seats 
installed at an angle between 18 degrees and 45 degrees from the 
airplane longitudinal centerline must meet the following:
    Side-Facing Seats Special Conditions:
    1. Head Injury Criteria:
    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 head-injury criterion (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., an interior wall or 
furnishing) that does not provide a homogenous contact surface for the 
expected range of occupants and yaw angles, then

[[Page 67830]]

additional analysis and tests may be required to demonstrate that the 
injury criteria are met for the area that an occupant could contact. 
For example, if different yaw angles could result in different airbag 
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 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 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.'' 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: The applicant 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.

    Inflatable Airbag Restraint Systems Special Conditions:
    If inflatable airbag restraint systems are installed, the airbag 
systems must meet the requirements of Airbus Model A330 special 
conditions no. 25-395-SC, ``Seats with Inflatable Lapbelts.''

    Issued in Des Moines, Washington, on December 6, 2019.
James E. Wilborn,
Acting Manager, Transport Standards Branch, Policy and Innovation 
Division, Aircraft Certification Service.
[FR Doc. 2019-26722 Filed 12-11-19; 8:45 am]
 BILLING CODE 4910-13-P