Special Conditions: The Boeing Model 737-8 Airplane; Dynamic Test Requirements for Single-Occupant Oblique Seats With 3-Point Seat Belt With Pretensioner, 39566-39569 [2024-10075]

Download as PDF ddrumheller on DSK120RN23PROD with RULES1 39566 Federal Register / Vol. 89, No. 91 / Thursday, May 9, 2024 / Rules and Regulations to the farm of origin without change in ownership. (4) They are moved directly from one State through another State and back to the original State. (5) They are moved as a commuter herd with a copy of the commuter herd agreement or other document, as agreed to by the States or Tribes involved in the movement. (6) Additionally, cattle and bison may be moved between shipping and receiving States or Tribes with documentation other than an ICVI, e.g., a brand inspection certificate, as agreed upon by animal health officials in the shipping and receiving States or Tribes. (7) The official identification number of cattle or bison must be recorded on the ICVI or alternate documentation unless: (i) The cattle or bison are moved from an approved livestock facility directly to a recognized slaughtering establishment; or (ii) The cattle and bison are sexually intact cattle or bison under 18 months of age or steers or spayed heifers; except that this paragraph (c)(7)(ii) does not apply to dairy cattle of any age or to cattle or bison used for rodeo, exhibition, or recreational purposes. (d) Horses and other equine species. Horses and other equine species moved interstate must be accompanied by an ICVI unless: (1) They are used as the mode of transportation (horseback, horse and buggy) for travel to another location and then return direct to the original location; or (2) They are moved from the farm or stable for veterinary medical examination or treatment and returned to the same location without change in ownership; or (3) They are moved directly from a location in one State through another State to a second location in the original State. (4) Additionally, equids may be moved between shipping and receiving States or Tribes with documentation other than an ICVI, e.g., an equine infectious anemia test chart, as agreed to by the shipping and receiving States or Tribes involved in the movement. (5) Equids moving commercially to slaughter must be accompanied by documentation in accordance with part 88 of this subchapter. Equine infectious anemia reactors moving interstate must be accompanied by documentation as required by part 75 of this subchapter. (e) Poultry. Poultry moved interstate must be accompanied by an ICVI unless: (1) They are from a flock participating in the National Poultry Improvement Plan (NPIP) and are accompanied by the VerDate Sep<11>2014 15:06 May 08, 2024 Jkt 262001 documentation required under the NPIP regulations (parts 145 through 147 of this chapter) for participation in that program; or (2) They are moved directly to a recognized slaughtering or rendering establishment; or (3) They are moved from the farm of origin for veterinary medical examination, treatment, or diagnostic purposes and either returned to the farm of origin without change in ownership or euthanized and disposed of at the veterinary facility; or (4) They are moved directly from one State through another State and back to the original State; or (5) They are moved between shipping and receiving States or Tribes with a VS Form 9–3 or documentation other than an ICVI, as agreed upon by animal health officials in the shipping and receiving States or Tribes; or (6) They are moved under permit in accordance with part 82 of this subchapter. (f) Sheep and goats. Sheep and goats moved interstate must be accompanied by documentation as required by part 79 of this subchapter. (g) Swine. Swine moved interstate must be accompanied by documentation in accordance with § 71.19 of this subchapter or, if applicable, with part 85 of this subchapter. (h) Captive cervids. Captive cervids moved interstate must be accompanied by documentation as required by part 77 of this subchapter. (Approved by the Office of Management and Budget under control number 0579–0327) Done in Washington, DC, this 26th day of April 2024. Jennifer Moffitt, Under Secretary for Marketing and Regulatory Programs. [FR Doc. 2024–09717 Filed 5–8–24; 8:45 am] BILLING CODE 3410–34–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 25 [Docket No. FAA–2024–0566; Special Conditions No. 25–861–SC] Special Conditions: The Boeing Model 737–8 Airplane; Dynamic Test Requirements for Single-Occupant Oblique Seats With 3-Point Seat Belt With Pretensioner Federal Aviation Administration (FAA), DOT. ACTION: Final special conditions; request for comments. AGENCY: PO 00000 Frm 00028 Fmt 4700 Sfmt 4700 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 transportcategory 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. DATES: This action is effective on HAECO on May 9, 2024. Send comments on or before June 24, 2024. ADDRESSES: Send comments identified by Docket No. FAA–2024–0566 using any of the following methods: • Federal eRegulations Portal: Go to 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, 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. Docket: Background documents or comments received may be read at 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, 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 john.shelden@faa.gov. SUPPLEMENTARY INFORMATION: The substance of these special conditions has been published in the Federal SUMMARY: E:\FR\FM\09MYR1.SGM 09MYR1 Federal Register / Vol. 89, No. 91 / Thursday, May 9, 2024 / Rules and Regulations Register 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. Privacy 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 www.regulations.gov, including any personal information you provide. The FAA will also post a report summarizing each substantive verbal contact received about these special conditions. Confidential Business Information 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. ddrumheller on DSK120RN23PROD with RULES1 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. VerDate Sep<11>2014 15:06 May 08, 2024 Jkt 262001 Background 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 twinengine, transport category airplane with a maximum passenger capacity of 189, and a maximum takeoff weight of approximately 182,200 pounds. Type Certification Basis 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.g., 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. Novel or Unusual Design Features 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 PO 00000 Frm 00029 Fmt 4700 Sfmt 4700 39567 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. Discussion 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 3point 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 SideFacing 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 severities, even with significant misalignment between the torso and pelvis, these injuries did not occur. Tests with an FAA H–III anthropomorphic test dummy (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 E:\FR\FM\09MYR1.SGM 09MYR1 ddrumheller on DSK120RN23PROD with RULES1 39568 Federal Register / Vol. 89, No. 91 / Thursday, May 9, 2024 / Rules and Regulations corresponds to a no-injury loading condition. Other restraint systems have been used to comply with the occupant injury criteria of § 25.562(c)(5). For instance, shoulder harnesses have been widely used on flight-attendant seats, flight-deck seats, in business jets, and in general-aviation airplanes to reduce occupant head injury in the event of an emergency landing. Special conditions, pertinent regulations, and published guidance relate to other restraint systems. However, the use of pretensioners in the restraint system on transport-airplane seats is a novel design. Pretensioner technology involves a step-change in loading experienced by the occupant for impacts below and above that at which the device deploys, because activation of the shoulder harness, at the point at which the pretensioner engages, interrupts uppertorso excursion. Such excursion could result in the head-injury criteria (HIC) being higher at an intermediate impact condition than that resulting from the maximum impact condition corresponding to the test conditions specified in § 25.562. See condition 7 in these special conditions. The ideal triangular maximumseverity pulse is defined in Advisory Circular (AC) 25.562–1B, ‘‘Dynamic Evaluation of Seat Restraint Systems and Occupant Protection on Transport Airplanes’’. For the evaluation and testing of less-severe pulses for purposes of assessing the effectiveness of the pretensioner setting, a similar triangular pulse should be used with acceleration, rise time, and velocity change scaled accordingly. The magnitude of the required pulse should not deviate below the ideal pulse by more than 0.5g until 1.33 t1 is reached, where t1 represents the time interval between 0 and t1 on the referenced pulse shape, as shown in AC 25.562–1B. This is an acceptable method of compliance to the test requirements of the special conditions. Additionally, the pretensioner might not provide protection, after actuation, during secondary impacts. Therefore, the case where a small impact is followed by a large impact should be addressed. If the minimum deceleration severity at which the pretensioner is set to deploy is unnecessarily low, the protection offered by the pretensioner may be lost by the time a second, larger impact occurs. The existing special conditions for Boeing Model 737–8 series airplane oblique seat installations do not address oblique seats with 3-point restraint systems equipped with pretensioners. VerDate Sep<11>2014 15:06 May 08, 2024 Jkt 262001 Therefore, the proposed configuration requires special conditions. Conditions 1 through 7 address occupant protection in consideration of the oblique-facing seats. Conditions 8 through 10 ensure that the pretensioner system activates when intended and protects a range of occupants under various accident conditions. Conditions 11 through 16 address maintenance and reliability of the pretensioner system, including any outside influences on the mechanism, to ensure it functions as intended. 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 737–8 series airplane, modified by HAECO. Should HAECO apply at a later date for a supplemental type certificate to modify any other model included on Type Certificate No. A16WE 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 series of airplanes. 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, and 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 Company Model 737–8 series airplanes, modified by HAECO. In addition to the requirements of § 25.562, passenger seats installed at an angle between 18 degrees and 45 degrees from the aircraft centerline must meet the following conditions: PO 00000 Frm 00030 Fmt 4700 Sfmt 4700 1. Body-to-Wall/Furnishing Contact If a seat is installed aft of a 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 that an occupant could contact. For example, if, in addition to a pretensioner restraint system, an airbag device is present, different yaw angles could result in different airbag device performance, then additional analysis or separate tests may be necessary to evaluate performance. 2. Neck Injury Criteria The seating system must protect the occupant from experiencing serious neck injury. In addition to a pretensioner restraint system, if an airbag device also 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: (1) Fzc = 1530 lbs. for tension (2) Fzc = 1385 lbs. for compression (3) Myc = 229 lb-ft in flexion (4) Myc = 100 lb-ft in extension (b) In addition, peak 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. 3. Spine and Torso Injury Criteria (a) The lumbar spine tension (Fz) cannot exceed 1200 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 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.’’ E:\FR\FM\09MYR1.SGM 09MYR1 Federal Register / Vol. 89, No. 91 / Thursday, May 9, 2024 / Rules and Regulations (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. 4. 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. 5. 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. 6. 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: HAECO 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. 7. Head Injury Criteria (HIC) The HIC value must not exceed 1000 at any condition at which the pretensioner does or does not deploy, up to the maximum severity pulse that corresponds to the test conditions specified in § 25.562. Tests must be performed to demonstrate this, taking into account any necessary tolerances for deployment. 8. Protection During Secondary Impacts ddrumheller on DSK120RN23PROD with RULES1 The pretensioner activation setting must be demonstrated to maximize the probability of the protection being available when needed, considering secondary impacts. 9. Protection of Occupants Other Than 50th Percentile Protection of occupants for a range of stature from a 2-year-old child to a 95th percentile male must be shown. For shoulder harnesses that include pretensioners, protection of occupants other than a 50th percentile male may VerDate Sep<11>2014 15:06 May 08, 2024 Jkt 262001 be shown by test or analysis. In addition, the pretensioner must not introduce a hazard to passengers due to the following seat configurations: (a) The seat occupant is holding an infant. (b) The seat occupant is a child in a child-restraint device. (c) The seat occupant is a pregnant woman. 10. Occupants Adopting the Brace Position Occupants in the traditional brace position when the pretensioner activates must not experience adverse effects from the pretensioner activation. 11. Inadvertent Pretensioner Actuation (a) The probability of inadvertent pretensioner actuation must be shown to be extremely remote (i.e., average probability per flight hour of less than 10–7). (b) The system must be shown not susceptible to inadvertent pretensioner actuation because of wear and tear, or inertia loads resulting from in-flight or ground maneuvers likely to be experienced in service. (c) The seated occupant must not be seriously injured because of inadvertent pretensioner actuation. (d) Inadvertent pretensioner activation must not cause a hazard to the airplane, nor cause serious injury to anyone who may be positioned close to the retractor or belt (e.g., seated in an adjacent seat or standing adjacent to the seat). 12. Availability of the Pretensioner Function Prior to Flight The design must provide means for a crewmember to verify the availability of the pretensioner function prior to each flight, or the probability of failure of the pretensioner function must be demonstrated to be extremely remote (i.e., average probability per flight hour of less than 10–7), between inspection intervals. 13. Incorrect Seat Belt Orientation The system design must ensure that any incorrect orientation (twisting) of the seat belt does not compromise the pretensioner protection function. 14. Contamination Protection The pretensioner mechanisms and controls must be protected from external contamination associated with that which could occur on or around passenger seating. 15. Prevention of Hazards The pretensioner system must not induce a hazard to passengers in case of fire, nor create a fire hazard, if activated. PO 00000 Frm 00031 Fmt 4700 Sfmt 4700 39569 16. Functionality After Loss of Power The system must function properly after loss of normal airplane electrical power, and after a transverse separation in the fuselage at the most critical location. A separation at the location of the system does not have to be considered. Issued in Kansas City, Missouri, on May 3, 2024. Patrick R. Mullen, Manager, Technical Policy Branch, Policy and Standards Division, Aircraft Certification Service. [FR Doc. 2024–10075 Filed 5–8–24; 8:45 am] BILLING CODE 4910–13–P FEDERAL MARITIME COMMISSION 46 CFR Part 541 [Docket No. FMC–2022–0066] RIN 3072–AC90 Demurrage and Detention Billing Requirements; Correction Federal Maritime Commission. Final rule; correction. AGENCY: ACTION: This document corrects the preamble to a final rule published in the Federal Register on February 26, 2024, concerning demurrage and detention billing requirements. This correction provides information regarding situations in which vessel-operating common carriers (VOCCs) enter into written contracts with motor carriers that use containers in the transportation of goods. DATES: This action is effective on May 9, 2024. ADDRESSES: To view background documents or comments received, you may use the Federal eRulemaking Portal at www.regulations.gov under Docket No. FMC–2022–0066. FOR FURTHER INFORMATION CONTACT: David Eng, Secretary; Phone: (202) 523– 5725; Email: secretary@fmc.gov. SUPPLEMENTARY INFORMATION: The Commission notes that it has received several inquiries concerning a possible discrepancy between the rule text and one paragraph in the preamble, found at page 14336.1 The Commission SUMMARY: 1 ‘‘In regard to the second comment, there seems to be a misunderstanding on the commenter’s part about the rule’s applicability. As discussed in the NPRM, a primary purpose of this rule is to stop demurrage and detention invoices from being sent to parties who did not negotiate contract terms with the billing party. That concern is not present where a motor carrier has directly contracted with a VOCC. Nothing in this rule, either in the proposed E:\FR\FM\09MYR1.SGM Continued 09MYR1

Agencies

[Federal Register Volume 89, Number 91 (Thursday, May 9, 2024)]
[Rules and Regulations]
[Pages 39566-39569]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-10075]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2024-0566; Special Conditions No. 25-861-SC]


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

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 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.

DATES: This action is effective on HAECO on May 9, 2024. Send comments 
on or before June 24, 2024.

ADDRESSES: Send comments identified by Docket No. FAA-2024-0566 using 
any of the following methods:
     Federal eRegulations Portal: Go to 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, 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.
    Docket: Background documents or comments received may be read at 
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, 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 [email protected].

SUPPLEMENTARY INFORMATION: The substance of these special conditions 
has been published in the Federal

[[Page 39567]]

Register 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.

Privacy

    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 www.regulations.gov, including any 
personal information you provide. The FAA will also post a report 
summarizing each substantive verbal contact received about these 
special conditions.

Confidential Business Information

    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.

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 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.

Type Certification Basis

    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.g., 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 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, the 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 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 Sec.  11.38, and they become part of the type 
certification basis under Sec.  21.101.

Novel or Unusual Design Features

    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.

Discussion

    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 severities, 
even with significant misalignment between the torso and pelvis, these 
injuries did not occur. Tests with an FAA H-III anthropomorphic test 
dummy (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

[[Page 39568]]

corresponds to a no-injury loading condition.
    Other restraint systems have been used to comply with the occupant 
injury criteria of Sec.  25.562(c)(5). For instance, shoulder harnesses 
have been widely used on flight-attendant seats, flight-deck seats, in 
business jets, and in general-aviation airplanes to reduce occupant 
head injury in the event of an emergency landing. Special conditions, 
pertinent regulations, and published guidance relate to other restraint 
systems. However, the use of pretensioners in the restraint system on 
transport-airplane seats is a novel design.
    Pretensioner technology involves a step-change in loading 
experienced by the occupant for impacts below and above that at which 
the device deploys, because activation of the shoulder harness, at the 
point at which the pretensioner engages, interrupts upper-torso 
excursion. Such excursion could result in the head-injury criteria 
(HIC) being higher at an intermediate impact condition than that 
resulting from the maximum impact condition corresponding to the test 
conditions specified in Sec.  25.562. See condition 7 in these special 
conditions.
    The ideal triangular maximum-severity pulse is defined in Advisory 
Circular (AC) 25.562-1B, ``Dynamic Evaluation of Seat Restraint Systems 
and Occupant Protection on Transport Airplanes''. For the evaluation 
and testing of less-severe pulses for purposes of assessing the 
effectiveness of the pretensioner setting, a similar triangular pulse 
should be used with acceleration, rise time, and velocity change scaled 
accordingly. The magnitude of the required pulse should not deviate 
below the ideal pulse by more than 0.5g until 1.33 t1 is reached, where 
t1 represents the time interval between 0 and t1 on the referenced 
pulse shape, as shown in AC 25.562-1B. This is an acceptable method of 
compliance to the test requirements of the special conditions.
    Additionally, the pretensioner might not provide protection, after 
actuation, during secondary impacts. Therefore, the case where a small 
impact is followed by a large impact should be addressed. If the 
minimum deceleration severity at which the pretensioner is set to 
deploy is unnecessarily low, the protection offered by the pretensioner 
may be lost by the time a second, larger impact occurs.
    The existing special conditions for Boeing Model 737-8 series 
airplane oblique seat installations do not address oblique seats with 
3-point restraint systems equipped with pretensioners. Therefore, the 
proposed configuration requires special conditions.
    Conditions 1 through 7 address occupant protection in consideration 
of the oblique-facing seats. Conditions 8 through 10 ensure that the 
pretensioner system activates when intended and protects a range of 
occupants under various accident conditions. Conditions 11 through 16 
address maintenance and reliability of the pretensioner system, 
including any outside influences on the mechanism, to ensure it 
functions as intended.
    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 737-8 series airplane, modified by HAECO. Should HAECO 
apply at a later date for a supplemental type certificate to modify any 
other model included on Type Certificate No. A16WE 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 series of airplanes. 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, and 
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 Company Model 737-8 series 
airplanes, modified by HAECO.
    In addition to the requirements of Sec.  25.562, passenger seats 
installed at an angle between 18 degrees and 45 degrees from the 
aircraft centerline must meet the following conditions:

1. Body-to-Wall/Furnishing Contact

    If a seat is installed aft of a 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 that an occupant could contact. For example, if, in 
addition to a pretensioner restraint system, an airbag device is 
present, different yaw angles could result in different airbag device 
performance, then additional analysis or separate tests may be 
necessary to evaluate performance.

2. Neck Injury Criteria

    The seating system must protect the occupant from experiencing 
serious neck injury. In addition to a pretensioner restraint system, if 
an airbag device also 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:
(1) Fzc = 1530 lbs. for tension
(2) Fzc = 1385 lbs. for compression
(3) Myc = 229 lb-ft in flexion
(4) Myc = 100 lb-ft in extension

    (b) In addition, peak 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.

3. Spine and Torso Injury Criteria

    (a) The lumbar spine tension (Fz) cannot exceed 1200 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 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.''

[[Page 39569]]

    (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.

4. 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.

5. 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.

6. 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:  HAECO 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.

7. Head Injury Criteria (HIC)

    The HIC value must not exceed 1000 at any condition at which the 
pretensioner does or does not deploy, up to the maximum severity pulse 
that corresponds to the test conditions specified in Sec.  25.562. 
Tests must be performed to demonstrate this, taking into account any 
necessary tolerances for deployment.

8. Protection During Secondary Impacts

    The pretensioner activation setting must be demonstrated to 
maximize the probability of the protection being available when needed, 
considering secondary impacts.

9. Protection of Occupants Other Than 50th Percentile

    Protection of occupants for a range of stature from a 2-year-old 
child to a 95th percentile male must be shown. For shoulder harnesses 
that include pretensioners, protection of occupants other than a 50th 
percentile male may be shown by test or analysis. In addition, the 
pretensioner must not introduce a hazard to passengers due to the 
following seat configurations:
    (a) The seat occupant is holding an infant.
    (b) The seat occupant is a child in a child-restraint device.
    (c) The seat occupant is a pregnant woman.

10. Occupants Adopting the Brace Position

    Occupants in the traditional brace position when the pretensioner 
activates must not experience adverse effects from the pretensioner 
activation.

11. Inadvertent Pretensioner Actuation

    (a) The probability of inadvertent pretensioner actuation must be 
shown to be extremely remote (i.e., average probability per flight hour 
of less than 10^-7).
    (b) The system must be shown not susceptible to inadvertent 
pretensioner actuation because of wear and tear, or inertia loads 
resulting from in-flight or ground maneuvers likely to be experienced 
in service.
    (c) The seated occupant must not be seriously injured because of 
inadvertent pretensioner actuation.
    (d) Inadvertent pretensioner activation must not cause a hazard to 
the airplane, nor cause serious injury to anyone who may be positioned 
close to the retractor or belt (e.g., seated in an adjacent seat or 
standing adjacent to the seat).

12. Availability of the Pretensioner Function Prior to Flight

    The design must provide means for a crewmember to verify the 
availability of the pretensioner function prior to each flight, or the 
probability of failure of the pretensioner function must be 
demonstrated to be extremely remote (i.e., average probability per 
flight hour of less than 10^-7), between inspection 
intervals.

13. Incorrect Seat Belt Orientation

    The system design must ensure that any incorrect orientation 
(twisting) of the seat belt does not compromise the pretensioner 
protection function.

14. Contamination Protection

    The pretensioner mechanisms and controls must be protected from 
external contamination associated with that which could occur on or 
around passenger seating.

15. Prevention of Hazards

    The pretensioner system must not induce a hazard to passengers in 
case of fire, nor create a fire hazard, if activated.

16. Functionality After Loss of Power

    The system must function properly after loss of normal airplane 
electrical power, and after a transverse separation in the fuselage at 
the most critical location. A separation at the location of the system 
does not have to be considered.

    Issued in Kansas City, Missouri, on May 3, 2024.
Patrick R. Mullen,
Manager, Technical Policy Branch, Policy and Standards Division, 
Aircraft Certification Service.
[FR Doc. 2024-10075 Filed 5-8-24; 8:45 am]
BILLING CODE 4910-13-P

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