Special Conditions: The Boeing Model 737-8 Airplane; Dynamic Test Requirements for Single-Occupant Oblique Seats With 3-Point Seat Belt With Pretensioner

<RULE> DEPARTMENT OF TRANSPORTATION <SUBAGY>Federal Aviation Administration</SUBAGY> <CFR>14 CFR Part 25</CFR> <DEPDOC>[Docket No. FAA-2024-0566; Special Conditions No. 25-861-SC]</DEPDOC> <SUBJECT>Special Conditions: The Boeing Model 737-8 Airplane; Dynamic Test Requirements for Single-Occupant Oblique Seats With 3-Point Seat Belt With Pretensioner</SUBJECT> <HD SOURCE="HED">AGENCY:</HD> Federal Aviation Administration (FAA), DOT. <HD SOURCE="HED">ACTION:</HD> Final special conditions; request for comments. <SUM> <HD SOURCE="HED">SUMMARY:</HD> These special conditions are issued for The Boeing Company (Boeing) Model 737-8 series airplane. This airplane, as modified by HAECO Cabin Solutions, LLC. (HAECO), will have a novel or unusual design feature 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 equipped with a 3-point seat belt with pretensioner. 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. </SUM> <EFFDATE> <HD SOURCE="HED">DATES:</HD> This action is effective on HAECO on May 9, 2024. Send comments on or before June 24, 2024. </EFFDATE> <HD SOURCE="HED">ADDRESSES:</HD> Send comments identified by Docket No. FAA-2024-0566 using any of the following methods: • <E T="03">Federal eRegulations Portal:</E> Go to <E T="03">www.regulations.gov</E> and follow the online instructions for sending your comments electronically. • <E T="03">Mail:</E> Send comments to Docket Operations, M-30, U.S. Department of Transportation, 1200 New Jersey Avenue SE, Room W12-140, West Building Ground Floor, Washington, DC 20590-0001. • <E T="03">Hand Delivery or Courier:</E> 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. • <E T="03">Fax:</E> Fax comments to Docket Operations at 202-493-2251. <E T="03">Docket:</E> Background documents or comments received may be read at <E T="03">www.regulations.gov</E> 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. <FURINF> <HD SOURCE="HED">FOR FURTHER INFORMATION CONTACT:</HD> John Shelden, Cabin Safety Section, AIR-624, Technical Policy Branch, Policy and Standards Division, Aircraft Certification Service, Federal Aviation Administration, 2200 South 216th Street, Des Moines, Washington 98198; telephone and fax (206) 231-3214; email <E T="03">john.shelden@faa.gov.</E> </FURINF> <SUPLINF> <HD SOURCE="HED">SUPPLEMENTARY INFORMATION:</HD> The substance of these special conditions has been published in the <E T="04"> Federal Register </E> for public comment in several prior instances with no substantive comments received. Therefore, the FAA finds, pursuant to 14 CFR 11.38(b), that new comments are unlikely, and notice and comment prior to this publication are unnecessary. <HD SOURCE="HD1">Privacy</HD> Except for Confidential Business Information (CBI) as described in the following paragraph, and other information as described in title 14, Code of Federal Regulations (14 CFR) 11.35, the FAA will post all comments received without change to <E T="03">www.regulations.gov,</E> including any personal information you provide. The FAA will also post a report summarizing each substantive verbal contact received about these special conditions. <HD SOURCE="HD1">Confidential Business Information</HD> Confidential Business Information (CBI) is commercial or financial information that is both customarily and actually treated as private by its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments responsive to this notice contain commercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this notice, it is important that you clearly designate the submitted comments as CBI. Please mark each page of your submission containing CBI as “PROPIN.” The FAA will treat such marked submissions as confidential under the FOIA, and the indicated comments will not be placed in the public docket of these proposed special conditions. Send submissions containing CBI to the individual listed in the For Further Information Contact section below. Comments the FAA receives, which are not specifically designated as CBI, will be placed in the public docket for these proposed special conditions. <HD SOURCE="HD1">Comments Invited</HD> 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. <HD SOURCE="HD1">Background</HD> On December 20, 2022, HAECO applied for a supplemental type certificate for the installation of oblique (side-facing) passenger seats that incorporate a 3-point restraint with pretensioner system in Boeing Model 737-8 series airplanes. The Boeing Model 737-8 series airplane is a twin-engine, transport category airplane with a maximum passenger capacity of 189, and a maximum takeoff weight of approximately 182,200 pounds. <HD SOURCE="HD1">Type Certification Basis</HD> Under the provisions of title 14, Code of Federal Regulations (14 CFR) 21.101, HAECO must show that the Model 737-8 series airplane, as changed, continue to meet the applicable provisions of the regulations listed in Type Certificate No. A16WE, 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 ( <E T="03">e.g.,</E> 14 CFR part 25) do not contain adequate or appropriate safety standards for the Boeing Model 737-8 series airplane because of a novel or unusual design feature, 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, the 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 737-8 series airplane must comply with the 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. <HD SOURCE="HD1">Novel or Unusual Design Features</HD> The Boeing Model 737-8 series airplane, as modified by HAECO, will incorporate a novel or unusual design feature which is the installation of oblique (side-facing) passenger seats, which may include a 3-point restraint system with pretensioner. These oblique seats may be installed at an angle of 18 to 45 degrees to the aircraft centerline and have surrounding furniture that introduces occupant alignment and loading concerns. <HD SOURCE="HD1">Discussion</HD> Title 14, Code of Federal Regulations (14 CFR) 25.785(d) requires that each occupant of a seat that makes more than an 18 degree angle with the vertical plane containing the airplane centerline must be protected from head injury by a safety belt and an energy absorbing rest that will support the arms, shoulders, head, and spine, or by a safety belt and shoulder harness that will prevent the head from contacting any injurious object. The proposed Boeing Model 737-8 airplane seat installation is novel in that the current requirements do not adequately address protection of the occupant's neck and spine for seating configurations that are positioned at angles greater than 18 degrees up to and including 45 degrees from the airplane centerline. The installation of passenger seats at angles of 18 to 45 degrees to the airplane centerline is 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 restraint system. In order to provide a level of safety that is equivalent to that afforded to occupants of forward and aft facing seating, additional airworthiness standards, in the form of new special conditions, are necessary. The FAA has been conducting and sponsoring research on appropriate injury criteria for oblique (side-facing) seat installations. To reflect current research findings, the FAA issued Policy Statement PS-AIR-25-27, “Technical Criteria for Approving Side-Facing Seats,” dated July 11, 2018, which defines injury criteria for oblique seats. 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 severitie ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Preview showing 10k of 23k characters. Full document text is stored and available for version comparison. ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━