Airworthiness Directives; The Boeing Company Airplanes

• Published date: 25 September 2023
• FR Document: 2023-20507
• Citation: 88 FR 65637
• Pages: 65637-65640
• Section: Proposed rules
• Issuer: Transportation Department,Federal Aviation Administration

Federal Register, Volume 88 Issue 184 (Monday, September 25, 2023)

[Federal Register Volume 88, Number 184 (Monday, September 25, 2023)]
                [Proposed Rules]
                [Pages 65637-65640]
                From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
                [FR Doc No: 2023-20507]
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                DEPARTMENT OF TRANSPORTATION
                Federal Aviation Administration
                14 CFR Part 39
                [Docket No. FAA-2023-1886; Project Identifier AD-2023-00429-T]
                RIN 2120-AA64
                Airworthiness Directives; The Boeing Company Airplanes
                AGENCY: Federal Aviation Administration (FAA), DOT.
                ACTION: Notice of proposed rulemaking (NPRM).
                -----------------------------------------------------------------------
                SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
                2009-01-02, which applies to certain Boeing Model 737-600, -700, -700C,
                -800, and -900 series airplanes. AD 2009-01-02 requires an inspection
                of frames between body station (BS) 360 and BS 907 to determine if
                certain support brackets of the air conditioning (A/C) outlet
                extrusions are installed, inspections for cracking of the frames around
                the attachment holes of the subject brackets, and repair if necessary.
                AD 2009-01-02 also requires installing new, improved fittings for all
                support brackets of the A/C outlet extrusions between BS 360 and BS
                907. Since the FAA issued AD 2009-01-02, the agency determined that
                certain repairs might develop fatigue cracks that could result in the
                inability of the frame to sustain limit load and therefore must be
                inspected. This proposed AD would continue to require the actions
                specified in AD 2009-01-02 and would also require repetitive
                inspections for cracking of certain repairs and repair if necessary.
                The FAA is proposing this AD to address the unsafe condition on these
                products.
                DATES: The FAA must receive comments on this proposed AD by November 9,
                2023.
                ADDRESSES: You may send comments, using the procedures found in 14 CFR
                11.43 and 11.45, by any of the following methods: Federal eRulemaking Portal: Go to regulations.gov. Follow
                the instructions for submitting comments. Fax: 202-493-2251. Mail: U.S. Department of Transportation, Docket
                Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
                Jersey Avenue SE, Washington, DC 20590. Hand Delivery: Deliver to Mail address above between 9
                a.m. and 5 p.m., Monday through Friday, except Federal holidays. AD Docket: You may examine the AD docket at regulations.gov under
                Docket No. FAA-2023-1886; or in person at Docket Operations between 9
                a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD
                docket contains this NPRM, any comments received, and other
                information. The street address for Docket Operations is listed above. Material Incorporated by Reference: For service information identified in this NPRM, contact
                Boeing Commercial Airplanes, Attention: Contractual & Data Services
                (C&DS), 2600 Westminster Blvd., MC 110 SK57, Seal Beach, CA 90740-5600;
                telephone 562-797-1717; website myboeingfleet.com. You may view this service information at the FAA,
                Airworthiness Products Section, Operational Safety Branch, 2200 South
                216th St., Des Moines, WA. For information on the availability of this
                material at the FAA, call 206-231-3195. It is also available at
                regulations.gov by searching for and locating Docket No. FAA-2023-1886.
                FOR FURTHER INFORMATION CONTACT: Owen F. Bley-Male, Aviation Safety
                Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
                231-3992; email: [email protected].
                SUPPLEMENTARY INFORMATION:
                Comments Invited The FAA invites you to send any written relevant data, views, or
                arguments about this proposal. Send your comments to an address listed
                under ADDRESSES. Include ``Docket No. FAA-2023-1886; Project Identifier
                AD-2023-00429-T'' at the beginning of your comments. The most helpful
                comments reference a specific portion of the proposal, explain the
                reason for any recommended change, and include supporting data. The FAA
                will consider all comments received by the closing date and may amend
                the proposal because of those comments. Except for Confidential Business Information (CBI) as described in
                the following paragraph, and other
                [[Page 65638]]
                information as described in 14 CFR 11.35, the FAA will post all
                comments received, without change, to regulations.gov, including any
                personal information you provide. The agency will also post a report
                summarizing each substantive verbal contact received about this
                proposed AD.
                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 NPRM 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 NPRM, 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 they will not be placed in the public
                docket of this NPRM. Submissions containing CBI should be sent to Owen
                F. Bley-Male, Aviation Safety Engineer, FAA, 2200 South 216th St., Des
                Moines, WA 98198; phone: 206-231-3992; email: [email protected].
                Any commentary that the FAA receives that is not specifically
                designated as CBI will be placed in the public docket for this
                rulemaking.
                Background The FAA issued AD 2009-01-02, Amendment 39-15780 (74 FR 4117,
                January 23, 2009) (AD 2009-01-02), for certain Boeing Model 737-600, -
                700, -700C, -800, and -900 series airplanes. AD 2009-01-02 was prompted
                by numerous reports of multiple cracks in the frame around the
                attachment holes of the support bracket of the A/C outlet extrusion. AD
                2009-01-02 requires a one-time general visual inspection of frames
                between BS 360 and BS 907 to determine if certain support brackets of
                the A/C outlet extrusions are installed, medium- and high-frequency
                eddy current inspections for cracking of the frames around the
                attachment holes of the subject brackets, and repair if necessary. AD
                2009-01-02 also requires installing new, improved fittings for all
                support brackets of the A/C outlet extrusions between BS 360 and BS
                907. AD 2009-01-02 refers to Boeing Special Attention Service Bulletin
                737-25-1544, Revision 1, dated January 16, 2008, as the appropriate
                source of service information for accomplishing the required actions.
                The agency issued AD 2009-01-02 to prevent frame cracking, which, if
                not corrected, could lead to a severed frame that, combined with
                cracking of the skin lap splice above stringer 10, could result in
                rapid decompression of the airplane.
                Actions Since AD 2009-01-02 Was Issued Since the FAA issued AD 2009-01-02, Boeing issued Special Attention
                Service Bulletin 737-25A1544, Revision 3, dated May 16, 2016, as an
                alternative method of compliance for AD 2009-01-02, which includes an
                alternative to making repairs using Boeing Special Attention Service
                Bulletin 737-25-1544, Revision 1, dated January 16, 2008. The FAA and
                Boeing determined that the repairs done using Boeing Special Attention
                Service Bulletin 737-25A1544, Revision 3, dated May 16, 2016, might
                develop fatigue cracks that could result in the inability of the frame
                to sustain limit load. Boeing subsequently issued Alert Service
                Bulletin 737-25A1544, Revision 4, dated February 15, 2022, which added
                damage tolerance inspections for certain BS 907 repairs done using
                Boeing Special Attention Service Bulletin 737-25A1544, Revision 3,
                dated May 16, 2016. The FAA determined that those post-repair
                inspections are necessary to address the unsafe condition.
                FAA's Determination The FAA is issuing this NPRM after determining that the unsafe
                condition described previously is likely to exist or develop on other
                products of the same type design.
                Related Service Information Under 1 CFR Part 51 The FAA reviewed Boeing Alert Service Bulletin 737-25A1544,
                Revision 4, dated February 15, 2022. This service information specifies
                procedures for a one-time general visual inspection of frames between
                BS 360 and BS 907 to determine if certain support brackets of the A/C
                outlet extrusions are installed; low-, medium- and high-frequency eddy
                current inspections for cracking of the frames around the attachment
                holes of the subject brackets, and repair if necessary; and
                installation of new, improved fittings for all support brackets of the
                A/C outlet extrusions between BS 360 and BS 907. This service
                information also specifies procedures for repetitive detailed and high-
                frequency eddy current inspections for cracking of certain repairs at
                BS 907 and repair if necessary. This AD also requires Boeing Special Attention Service Bulletin
                737-25-1544, Revision 1, dated January 16, 2008, which the Director of
                the Federal Register approved for incorporation by reference as of
                February 27, 2009 (74 FR 4117, January 23, 2009). This service information is reasonably available because the
                interested parties have access to it through their normal course of
                business or by the means identified in the ADDRESSES section.
                Proposed AD Requirements in This NPRM This proposed AD would require accomplishing the actions specified
                in the service information described previously, except for any
                differences identified as exceptions in the regulatory text of this
                proposed AD. For information on the procedures and compliance times,
                see this service information at regulations.gov by searching for and
                locating Docket No. FAA-2023-1886.
                Costs of Compliance The FAA estimates that this AD, if adopted as proposed, would
                affect 738 airplanes of U.S. registry. The FAA estimates the following
                costs to comply with this proposed AD: Estimated Costs
                -------------------------------------------------------------------------------------------------------------------------------------------------------- Action Labor cost Parts cost Cost per product Cost on U.S. operators
                --------------------------------------------------------------------------------------------------------------------------------------------------------
                General visual inspection (retained 1 work-hour x $85 per $0....................... $85............................ $62,730. actions from AD 2009-01-02). hour = $85.
                Eddy current inspections (retained Up to 216 work-hours x 0........................ Up to 18,360................... Up to 13,549,680. actions from AD 2009-01-02). 85 per hour = Up to 18,360.
                Replace support fittings (retained Up to 346 work-hours x Up to 28,789............. Up to 57,889................... Up to 42,722,082. actions from AD 2009-01-02). 85 per hour = Up to 29,410.
                [[Page 65639]] Post-repair Inspections (new 42 work-hours x 85 per 0........................ 3,570 per inspection cycle..... 2,634,660 per inspection cycle. proposed action). hour = 3,570 per inspection cycle.
                -------------------------------------------------------------------------------------------------------------------------------------------------------- The FAA has received no definitive data on which to base the cost
                estimates for the on-condition repairs that would be required based on
                the results of the inspections specified in this proposed AD.
                Authority for This Rulemaking Title 49 of the United States Code specifies the FAA's authority to
                issue rules on aviation safety. Subtitle I, Section 106, describes the
                authority of the FAA Administrator. Subtitle VII, Aviation Programs,
                describes in more detail the scope of the Agency's authority. The FAA is issuing this rulemaking under the authority described in
                Subtitle VII, Part A, Subpart III, Section 44701, General requirements.
                Under that section, Congress charges the FAA with promoting safe flight
                of civil aircraft in air commerce by prescribing regulations for
                practices, methods, and procedures the Administrator finds necessary
                for safety in air commerce. This regulation is within the scope of that
                authority because it addresses an unsafe condition that is likely to
                exist or develop on products identified in this rulemaking action.
                Regulatory Findings The FAA has determined that this proposed AD would not have
                federalism implications under Executive Order 13132. This proposed AD
                would not have a substantial direct effect on the States, on the
                relationship between the national Government and the States, or on the
                distribution of power and responsibilities among the various levels of
                government. For the reasons discussed above, I certify that the proposed
                regulation: (1) Is not a ``significant regulatory action'' under Executive
                Order 12866, (2) Would not affect intrastate aviation in Alaska, and (3) Would not have a significant economic impact, positive or
                negative, on a substantial number of small entities under the criteria
                of the Regulatory Flexibility Act.
                List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by
                reference, Safety.
                The Proposed Amendment Accordingly, under the authority delegated to me by the
                Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
                PART 39--AIRWORTHINESS DIRECTIVES
                0
                1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701.
                Sec. 39.13 [Amended]
                0
                2. The FAA amends Sec. 39.13 by:
                0
                a. Removing Airworthiness Directive (AD) 2009-01-02, Amendment 39-15780
                (74 FR 4117, January 23, 2009), and
                0
                b. Adding the following new AD:
                The Boeing Company: Docket No. FAA-2023-1886; Project Identifier AD-
                2023-00429-T.
                (a) Comments Due Date The FAA must receive comments on this airworthiness directive
                (AD) action by November 9, 2023.
                (b) Affected ADs This AD replaces AD 2009-01-02, Amendment 39-15780 (74 FR 4117,
                January 23, 2009) (AD 2009-01-02).
                (c) Applicability This AD applies to Boeing Model 737-600, -700, -700C, -800, and
                -900 series airplanes, certificated in any category, as identified
                in Boeing Special Attention Service Bulletin 737-25A1544, Revision
                4, dated February 15, 2022.
                (d) Subject Air Transport Association (ATA) of America Code 25, Equipment/
                Furnishing.
                (e) Unsafe Condition This AD was prompted by numerous reports of multiple cracks in
                the frame around the attachment holes of the support bracket of the
                air conditioning (A/C) outlet extrusion. Also, the FAA determined
                that certain repairs done to comply with AD 2009-01-02 might develop
                fatigue cracks that could result in the inability of the frame to
                sustain limit load and must be inspected. The FAA is issuing this AD
                to address frame cracking, which, if not corrected, could lead to a
                severed frame that, combined with cracking of the skin lap splice
                above stringer 10, could result in rapid decompression of the
                airplane.
                (f) Compliance Comply with this AD within the compliance times specified,
                unless already done.
                (g) Retained Inspection, With New Service Information This paragraph restates the requirements of paragraph (f) of AD
                2009-01-02, with new service information. Before the accumulation of
                36,000 total flight cycles, or within 72 months after February 27,
                2009 (the effective date of AD 2009-01-02), whichever occurs later,
                except as required by paragraph (i) of this AD: Do a general visual
                inspection to determine if the support brackets of the A/C outlet
                extrusions between body station (BS) 360 and BS 907 have two-rivet
                attachment fittings in accordance with Part 2 of the Accomplishment
                Instructions of Boeing Special Attention Service Bulletin 737-25-
                1544, Revision 1, dated January 16, 2008, or Boeing Alert Service
                Bulletin 737-25A1544, Revision 4, dated February 15, 2022; except at
                the locations identified in the notes of Step 3.B.1 of Part 1 of the
                Accomplishment Instructions of Boeing Special Attention Service
                Bulletin 737-25-1544, Revision 1, dated January 16, 2008, or Boeing
                Alert Service Bulletin 737-25A1544, Revision 4, dated February 15,
                2022. As of the effective date of this AD, only use Boeing Alert
                Service Bulletin 737-25A1544, Revision 4, dated February 15, 2022,
                for the actions required by paragraph (g) of this AD. (1) For any support bracket attached with three or more rivets:
                No further action is required by paragraph (g) of this AD. (2) For any subject support bracket having a two-rivet
                attachment fitting: Before the accumulation of 36,000 total flight
                cycles, or within 72 months after February 27, 2009 (the effective
                date of AD 2009-01-02), whichever occurs later, except as required
                by paragraph (i) of this AD, do medium- and high-frequency eddy
                current inspections for cracking of the frame around the attachment
                holes of the support bracket, in accordance with Part 2 of the
                Accomplishment Instructions of Boeing Special Attention Service
                Bulletin 737-25-1544, Revision 1, dated January 16, 2008, or do low-
                , medium- and high-frequency eddy current inspections for cracking
                of the frame around the attachment holes of the support bracket, in
                accordance with Part 2 of the Accomplishment Instructions of Boeing
                Alert Service Bulletin 737-25A1544, Revision 4, dated February 15,
                2022. If any cracking is discovered, before further flight, repair
                the cracking in accordance with Part 3 of the Accomplishment
                Instructions of Boeing Special Attention Service Bulletin 737-25-
                1544, Revision 1, dated January 16, 2008, or Boeing Alert Service
                Bulletin 737-25A1544, Revision 4, dated February 15, 2022, except
                [[Page 65640]]
                as required by paragraph (k)(2) of this AD. As of the effective date
                of this AD, only use Boeing Alert Service Bulletin 737-25A1544,
                Revision 4, dated February 15, 2022, for the actions required by
                paragraph (g)(2) of this AD.
                (h) Retained Modification With New Service Information This paragraph restates the requirements of paragraph (g) of AD
                2009-01-02, with new service information. Except as required by
                paragraph (i) of this AD: Before the accumulation of 36,000 total
                flight cycles, or within 72 months after February 27, 2009 (the
                effective date of AD 2009-01-02), whichever occurs later, replace
                the support fittings of all A/C outlet extrusions between BS 360 and
                BS 907 with new, improved support fittings, in accordance with Part
                4 of the Accomplishment Instructions of Boeing Special Attention
                Service Bulletin 737-25-1544, Revision 1, dated January 16, 2008, or
                Boeing Alert Service Bulletin 737-25A1544, Revision 4, dated
                February 15, 2022. As of the effective date of this AD, only use
                Boeing Alert Service Bulletin 737-25A1544, Revision 4, dated
                February 15, 2022, for the actions required by paragraph (h) of this
                AD.
                (i) Retained Compliance Time for Certain Airplanes With No Changes This paragraph restates the compliance time specified in
                paragraph (h) of AD 2009-01-02, with no changes. For airplanes on
                which Boeing Business Jet (BBJ) lower cabin altitude modification is
                incorporated in accordance with Supplemental Type Certificate
                ST01697SE: Before the accumulation of 18,000 total flight cycles, or
                within 72 months after February 27, 2009 (the effective date of AD
                2009-01-02), whichever occurs later, do the actions specified in
                paragraphs (g) and (h) of this AD.
                (j) New Requirements of This AD For Groups 1 through 4 and Group 6 as identified in Boeing Alert
                Service Bulletin 737-25A1544, Revision 4, dated February 15, 2022:
                Except as specified in paragraph (k) of this AD: At the applicable
                time specified in Table 2 of the ``Compliance'' paragraph of Boeing
                Alert Service Bulletin 737-25A1544, Revision 4, dated February 15,
                2022, do a detailed inspection and a high-frequency eddy current
                inspection for cracking of the repaired area at frame BS 907, and do
                all applicable repairs before further flight, in accordance with the
                Accomplishment Instructions of in Boeing Alert Service Bulletin 737-
                25A1544, Revision 4, dated February 15, 2022. Repeat the inspections
                thereafter at the applicable time specified in Table 2 of the
                ``Compliance'' paragraph of Boeing Alert Service Bulletin 737-
                25A1544, Revision 4, dated February 15, 2022.
                (k) Exceptions to Service Information Specifications (1) Where the Compliance Time column of Table 2 in the
                ``Compliance'' paragraph of Boeing Alert Service Bulletin 737-
                25A1544, Revision 4, dated February 15, 2022, uses the phrase ``the
                Revision 4 date of this Service Bulletin,'' this AD requires using
                ``the effective date of this AD.'' (2) Where Boeing Alert Service Bulletin 737-25A1544, Revision 4,
                dated February 15, 2022, specifies contacting Boeing, this AD
                requires repair before further flight using a method approved in
                accordance with the procedures specified in paragraph (m) of this
                AD. (3) For airplanes on which Boeing Business Jet Lower Cabin
                Altitude Supplemental Type Certificate (STC) ST01697SE (drs.faa.gov/browse/excelExternalWindow/0812969A86AF879B8625766400600105.0001)
                (6,500 feet maximum cabin altitude in lieu of 8,000 feet) has been
                incorporated, the flight-cycle related compliance times for the
                inspections required by paragraph (j) of this AD are different from
                those specified in Table 2 of the ``Compliance'' paragraph in Boeing
                Alert Service Bulletin 737-25A1544, Revision 4, dated February 15,
                2022. All initial compliance times specified in total flight cycles
                or flight cycles must be reduced to half of those specified in Table
                2 of the ``Compliance'' paragraph in Boeing Alert Service Bulletin
                737-25A1544, Revision 4, dated February 15, 2022. All repetitive
                interval compliance times specified in flight cycles must be reduced
                to one-quarter of those specified in Table 2 of the ``Compliance''
                paragraph in Boeing Alert Service Bulletin 737-25A1544, Revision 4,
                dated February 15, 2022.
                (l) Credit for Previous Actions (1) This paragraph provides credit for the actions specified in
                paragraphs (g) and (h) of this AD, if those actions were performed
                before February 27, 2009 (the effective date of AD 2009-01-02) using
                Boeing Alert Service Bulletin 737-25-1544, dated October 4, 2006. (2) This paragraph provides credit for the actions specified in
                paragraphs (g) and (h) of this AD, if those actions were performed
                before the effective date of this AD using Boeing Special Attention
                Service Bulletin 737-25-1544, Revision 2, dated March 23, 2011, or
                Boeing Special Attention Service Bulletin 737-25-1544, Revision 3,
                dated May 16, 2016.
                (m) Alternative Methods of Compliance (AMOCs) (1) The Manager, AIR-520, Continued Operational Safety Branch,
                FAA, has the authority to approve AMOCs for this AD, if requested
                using the procedures found in 14 CFR 39.19. In accordance with 14
                CFR 39.19, send your request to your principal inspector or
                responsible Flight Standards Office, as appropriate. If sending
                information directly to the manager of AIR-520, Continued
                Operational Safety Branch, send it to the attention of the person
                identified in paragraph (n)(1) of this AD. Information may be
                emailed to: [email protected]. (2) Before using any approved AMOC, notify your appropriate
                principal inspector, or lacking a principal inspector, the manager
                of the responsible Flight Standards Office. (3) An AMOC that provides an acceptable level of safety may be
                used for any repair, modification, or alteration required by this AD
                if it is approved by The Boeing Company Organization Designation
                Authorization (ODA) that has been authorized by the Manager, AIR-
                520, Continued Operational Safety Branch, FAA, to make those
                findings. To be approved, the repair method, modification deviation,
                or alteration deviation must meet the certification basis of the
                airplane, and the approval must specifically refer to this AD. (4) AMOCs approved for AD 2009-01-02 are approved as AMOCs for
                the corresponding provisions of paragraphs (g) through (i) of this
                AD.
                (n) Related Information (1) For more information about this AD, contact Owen F. Bley-
                Male, Aviation Safety Engineer, FAA, 2200 South 216th St., Des
                Moines, WA 98198; phone: 206-231-3992; email: [email protected]. (2) Service information identified in this AD that is not
                incorporated by reference is available at the addresses specified in
                paragraphs (o)(5) and (6) of this AD.
                (o) Material Incorporated by Reference (1) The Director of the Federal Register approved the
                incorporation by reference (IBR) of the service information listed
                in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51. (2) You must use this service information as applicable to do
                the actions required by this AD, unless this AD specifies otherwise. (3) The following service information was approved for IBR on
                [DATE 35 DAYS AFTER PUBLICATION OF THE FINAL RULE]. (i) Boeing Alert Service Bulletin 737-25A1544, Revision 4, dated
                February 15, 2022. (ii) [Reserved] (4) The following service information was approved for IBR on
                February 27, 2009 (74 FR 4117, January 23, 2009). (i) Boeing Special Attention Service Bulletin 737-25-1544,
                Revision 1, dated January 16, 2008. (ii) [Reserved] (5) For service information identified in this AD, contact
                Boeing Commercial Airplanes, Attention: Contractual & Data Services
                (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-
                5600; telephone 562-797-1717; website myboeingfleet.com. (6) You may view this service information at the FAA,
                Airworthiness Products Section, Operational Safety Branch, 2200
                South 216th St., Des Moines, WA. For information on the availability
                of this material at the FAA, call 206-231-3195. (7) You may view this service information that is incorporated
                by reference at the National Archives and Records Administration
                (NARA). For information on the availability of this material at
                NARA, email [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html. Issued on September 18, 2023.
                Victor Wicklund,
                Deputy Director, Compliance & Airworthiness Division, Aircraft
                Certification Service.
                [FR Doc. 2023-20507 Filed 9-22-23; 8:45 am]
                BILLING CODE 4910-13-P