Airworthiness Directives; General Electric Company Engines

• Published date: 10 July 2024
• Citation: 89 FR 56674
• Pages: 56674-56676
• FR Document: 2024-14873
• Section: Proposed rules
• Issuer: Transportation Department,Federal Aviation Administration

Federal Register, Volume 89 Issue 132 (Wednesday, July 10, 2024)

[Federal Register Volume 89, Number 132 (Wednesday, July 10, 2024)]
                [Proposed Rules]
                [Pages 56674-56676]
                From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
                [FR Doc No: 2024-14873]
                ========================================================================
                Proposed Rules
                 Federal Register
                ________________________________________________________________________
                This section of the FEDERAL REGISTER contains notices to the public of
                the proposed issuance of rules and regulations. The purpose of these
                notices is to give interested persons an opportunity to participate in
                the rule making prior to the adoption of the final rules.
                ========================================================================
                Federal Register / Vol. 89, No. 132 / Wednesday, July 10, 2024 /
                Proposed Rules
                [[Page 56674]]
                DEPARTMENT OF TRANSPORTATION
                Federal Aviation Administration
                14 CFR Part 39
                [Docket No. FAA-2024-1883; Project Identifier AD-2023-01120-E]
                RIN 2120-AA64
                Airworthiness Directives; General Electric Company Engines
                AGENCY: Federal Aviation Administration (FAA), DOT.
                ACTION: Notice of proposed rulemaking (NPRM).
                -----------------------------------------------------------------------
                SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
                for all General Electric Company (GE) Model CF34-10E2A1, CF34-10E6,
                CF34-10E6A1, CF34-10E7, and CF34-10E7-B engines with certain part-
                numbered high-pressure turbine (HPT) shroud/low pressure turbine (LPT)
                nozzle assemblies installed. This proposed AD was prompted by a report
                of failed retention features of the inner and outer support air ducts
                (commonly referred to as spoolies) discovered during engine
                disassembly. This proposed AD would require a visual inspection of the
                combustion case for wear and gouges, repair if necessary, and rework of
                the affected HPT shroud/LPT nozzle assemblies. 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 August 26,
                2024.
                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-2024-1883; 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 GE service information, contact General Electric
                Company, 1 Neumann Way, Cincinnati, OH 45215; phone: (513) 552-3272;
                email: ge.com">aviation.fleetsupport@ge.com; website: ge.com.
                 You may view this service information that is incorporated
                by reference at the FAA, Airworthiness Products Section, Operational
                Safety Branch, 1200 District Avenue, Burlington, MA 01803. For
                information on the availability of this material at the FAA, call (817)
                222-5110.
                FOR FURTHER INFORMATION CONTACT: Alexei Marqueen, Aviation Safety
                Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone:
                (781) 238-7178; 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-2024-1883; Project Identifier
                AD-2023-01120-E'' 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
                this proposal because of those comments.
                 Except for Confidential Business Information (CBI) as described in
                the following paragraph, and other 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 NPRM.
                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
                Alexei Marqueen, Aviation Safety Engineer, FAA, 2200 South 216th
                Street, Des Moines, WA 98198. Any commentary that the FAA receives
                which is not specifically designated as CBI will be placed in the
                public docket for this rulemaking.
                Background
                 The FAA received a report from the manufacturer that during
                disassembly, the retention features of the inner and outer support air
                ducts on GE Model CF34-10E series engines were found to have failed.
                The retention features include a retaining ring, which becomes
                plastically deformed during installation. Vibrations loosen the
                retaining ring until it disengages. With the retaining ring disengaged,
                the outer support air duct has no radial constraint, and releases and
                migrates due to gravity, impacting the inner wall of the combustion
                case causing case wall damage. If this damage has been repaired in the
                past and after the repair the support air duct liberates and causes
                more damage, then the remaining wall thickness is not sufficient to
                sustain the loading from a fan-blade-out or other extreme event. This
                condition, if not addressed, could result in the inner surface of the
                combustion case having reduced load carrying capability for fan blade
                out or other extreme event with possible engine separation and loss of
                the airplane.
                [[Page 56675]]
                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 GE Service Bulletin (SB) 72-0351 R01, dated July
                17, 2019, which provides instructions for a visual inspection of the
                combustion case for wear and gouges, repair if necessary, and rework of
                the affected HPT shroud/LPT nozzle assemblies. This service bulletin
                also introduces a new HPT shroud/LPT nozzle assembly P/N 2205M38G07
                with welded retaining rings. 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
                ADDRESSES.
                Proposed AD Requirements in This NPRM
                 This proposed AD requires a visual inspection of the combustion
                case for wear and gouges, repair if necessary, and rework of the
                affected HPT shroud/LPT nozzle assemblies to add a positive retention
                of the support air duct.
                Costs of Compliance
                 The FAA estimates that this AD, if adopted as proposed, would
                affect 300 engines installed on airplanes of U.S. registry.
                 The FAA estimates the following costs to comply with this proposed
                AD:
                 Estimated Costs
                ----------------------------------------------------------------------------------------------------------------
                 Cost per Cost on U.S.
                 Action Labor cost Parts cost product operators
                ----------------------------------------------------------------------------------------------------------------
                Visual inspection of the combustion 8 work-hours x $85 per $0 $680 $204,000
                 case inner shell surface. hour = $680.
                Rework of the affected HPT shroud/LPT 8 work-hours x $85 per 0 680 204,000
                 nozzle assembly. hour = $680.
                ----------------------------------------------------------------------------------------------------------------
                 The FAA estimates the following costs to do any necessary repairs
                that would be required based on the results of the proposed inspection.
                The agency has no way of determining the number of engines that might
                need these repairs.
                 On-Condition Costs
                ----------------------------------------------------------------------------------------------------------------
                 Cost per
                 Action Labor cost Parts cost product
                ----------------------------------------------------------------------------------------------------------------
                Repair the combustion case.................... 8 work-hours x $85 per hour = $0 $680
                 $680.
                Replace the combustion case................... 8 work-hours x $85 per hour = 647,000 647,680
                 $680.
                ----------------------------------------------------------------------------------------------------------------
                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 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 this 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 adding the following new airworthiness
                directive:
                General Electric Company: Docket No. FAA-2024-1883; Project
                Identifier AD-2023-01120-E.
                (a) Comments Due Date
                 The FAA must receive comments on this airworthiness directive
                (AD) by August 26, 2024.
                (b) Affected ADs
                 None.
                (c) Applicability
                 This AD applies to General Electric Company (GE) Model CF34-
                10E2A1, CF34-10E6, CF34-10E6A1, CF34-10E7, and CF34-10E7-B engines
                with an installed high-pressure turbine (HPT) shroud/low-pressure
                turbine (LPT) nozzle assembly having part number (P/N) 2205M38G01,
                2205M38G02, 2205M38G03, 2205M38G04, or 2205M38G05.
                [[Page 56676]]
                (d) Subject
                 Joint Aircraft System Component (JASC) Code 7250, Turbine
                Section.
                (e) Unsafe Condition
                 This AD was prompted by a report of failed retention features of
                the inner and outer support air ducts (commonly referred to as
                spoolies) discovered during engine disassembly. The FAA is issuing
                this AD to prevent failure of the combustion case. The unsafe
                condition, if not addressed, could result in the inner surface of
                the combustion case having reduced load carrying capability for fan
                blade out or other extreme event with possible engine separation and
                loss of the airplane.
                (f) Compliance
                 Comply with this AD within the compliance times specified,
                unless already done.
                (g) Required Actions
                 (1) At the next engine shop visit after the effective date of
                this AD, do a visual inspection of the combustion case inner shell
                surface for wear and gouges in accordance with paragraph 3.A.(1) and
                (2) of the Accomplishment Instructions of GE CF34-10E Service
                Bulletin (SB) 72-0351 R01, dated July 17, 2019 (SB 72-0351 R01).
                 (i) If any wear or gouges are found during any inspection
                required by paragraph (g)(1) of this AD, before further flight,
                repair the combustion case in accordance with Table 1 of SB 72-0351
                R01.
                 (ii) If any wear or gouges exceed the maximum repairable limit
                in accordance with Table 1 of SB 72-0351 R01, before further flight,
                remove the combustion case from service.
                 (2) At the next engine shop visit after the effective date of
                this AD, rework the affected HPT shroud/LPT nozzle assembly, in
                accordance with paragraph 3.B. of the Accomplishment Instructions of
                SB 72-0351 R01.
                (h) Definition
                 For the purpose of this AD, an ``engine shop visit'' is defined
                as when the HPT shroud/LPT nozzle assembly or the HPT rotor disk is
                removed from the engine.
                (i) 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 local
                Flight Standards District Office, as appropriate. If sending
                information directly to the manager of the AIR-520 Continued
                Operational Safety Branch, send it to the attention of the person
                identified in paragraph (j) of this AD and email to: [email protected].
                 (2) Before using any approved AMOC, notify your appropriate
                principal inspector, or lacking a principal inspector, the manager
                of the local flight standards district office/certificate holding
                district office.
                (j) Additional Information
                 For more information about this AD, contact Alexei Marqueen,
                Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines,
                WA 98198; phone: (781) 238-7178; email: [email protected].
                (k) 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 the AD specifies otherwise.
                 (i) General Electric Company (GE) CF34-10E Service Bulletin 72-
                0351 R01, dated July 17, 2019.
                 (ii) [Reserved]
                 (3) For GE service information, contact General Electric
                Company, 1 Neumann Way, Cincinnati, OH 45215; phone: (513) 552-3272;
                email: ge.com">aviation.fleetsupport@ge.com; website: ge.com.
                 (4) You may view this service information that is incorporated
                by reference at the FAA, Airworthiness Products Section, Operational
                Safety Branch, 1200 District Avenue, Burlington, MA 01803. For
                information on the availability of this material at the FAA, call
                (817) 222-5110.
                 (5) You may view this material at the National Archives and
                Records Administration (NARA). For information on the availability
                of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].
                 Issued on July 1, 2024.
                Peter A. White,
                Deputy Director, Integrated Certificate Management Division, Aircraft
                Certification Service.
                [FR Doc. 2024-14873 Filed 7-9-24; 8:45 am]
                BILLING CODE 4910-13-P