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 Department of Transportation Federal Aviation Administration 14 CFR Part 39
[Docket No. FAA-2024-0231; Project Identifier AD-2023-01037-T]
RIN 2120-AA64
 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 The Boeing Company Model 787-8, 
                        ( print page 12786)
                        787-9, and 787-10 airplanes. This proposed AD was prompted by a report of heat damage on multiple engine inlets around the engine anti-ice (EAI) duct within the inlet aft compartment. This proposed AD would require doing a records check and updating the operator's existing minimum equipment list (MEL), inspecting the left and right engine inlet cowl assembly for signs of heat damage around the EAI duct, installing or replacing the EAI duct seals, repairing any damage, and replacing the engine inlet if necessary. This proposed AD would also prohibit the installation of engine inlets under certain conditions. 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 April 5, 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-2024-0231; 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-2024-0231.
 FOR FURTHER INFORMATION CONTACT: Tak Kobayashi, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone 206-231-3553; email 
                        *takahisa.kobayashi@faa.gov.*


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-2024-0231; Project Identifier AD-2023-01037-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 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 Tak Kobayashi, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone 206-231-3553; email 
                    *takahisa.kobayashi@faa.gov.*
                     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 has received a report indicating that damage was found during overhaul on multiple inlets around the EAI duct within the inlet aft compartment. After investigation, it was found that the seals between the inner and outer ducts and between the outer duct and the aft compartment were missing. This led to EAI air leaking into the aft compartment exposing inlet components to high temperatures. This condition, if not addressed, could cause damage around the EAI duct, leading to reduced structural strength and departure of the inlet from the airplane, resulting in subsequent loss of continued safe flight and landing or injury to occupants from a departed inlet contacting the airplane. 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 Requirements Bulletin B787-81205-SB540023-00 RB, Issue 001, dated September 22, 2023; and Boeing Alert Requirements Bulletin B787-81205-SB540024-00 RB, Issue 001, dated September 22, 2023. This service information specifies procedures for incorporating (or verifying incorporation of) an updated dispatch deviation guide (DDG) for item 30-21-01-02 into the operator's existing MEL, checking records to determine whether the inlet has been dispatched under MEL item 30-21-01-02 or 30-21-01-07 before incorporation of the DDG 30-21-01-02 update, and applicable related investigative and corrective actions, including general visual inspection for signs of heat damage around the EAI duct, conductivity measurement and hardness test of areas with heat damage, replacement/installation of the periseal and aft seal, and repair or replacement of the engine inlet. These documents are distinct since they apply to different airplane configurations. 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 would require accomplishing the actions specified in the service information already described, except as specified under “Difference Between this Proposed AD and the Service Information” and except for any differences identified as exceptions in the regulatory text of this proposed AD. This proposed AD would 
                    ( print page 12787)
                    also prohibit the installation of affected parts under certain conditions. For information on the procedures and compliance times, see this service information at 
                    *regulations.gov*
                     under Docket No. FAA-2024-0231. Difference Between This Proposed AD and the Service Information The applicability in this proposed AD is not limited to the airplanes identified in paragraph A., “Effectivity,” of Boeing Alert Requirements Bulletin B787-81205-SB540023-00 RB or Boeing Alert Requirements Bulletin B787-81205-SB540024-00 RB, both Issue 001 and both dated September 22, 2023. This service information does not contain a complete list of all airplanes that may be affected by the identified unsafe condition. Therefore, the applicability of this proposed AD is all Model 787-8, 787-9, and 787-10 airplanes. Interim Action The FAA considers that this proposed AD would be an interim action. An investigation is ongoing. If final action is later identified, the FAA might consider further rulemaking then. Costs of Compliance The FAA estimates that this AD, if adopted as proposed, would affect 110 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. operatorsMEL update and records check
5 work-hours × $85 per hour = $425
$0
$425
$46,750
 The FAA estimates the following costs to do any investigative actions or repairs/replacements that would be required based on the results of the records check. The agency has no way of determining the number of airplanes that might need these actions: On-Condition Costs
Action
Labor cost
Parts cost
Cost per
                             productInspection
3 work-hours × $85 per hour = $255
$0
$255
 The FAA has received no definitive data on which to base the cost estimates for the conductivity measurement, the hardness test, inlet replacement, and installation of a new periseal and aft seal, as specified in this proposed AD. The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some or all of the costs of this proposed AD may be covered under warranty, thereby reducing the cost impact on affected operators. 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
 1.The authority citation for part 39 continues to read as follows: Authority:
                    49 U.S.C. 106(g), 40113, 44701. § 39.13
 2.The FAA amends § 39.13 by adding the following new airworthiness directive: **The Boeing Company:**
                         Docket No. FAA-2024-0231; Project Identifier AD-2023-01037-T. (a) Comments Due Date The FAA must receive comments on this airworthiness directive (AD) by April 5, 2024. (b) Affected ADs None. (c) Applicability This AD applies to all The Boeing Company Model 787-8, 787-9, and 787-10 airplanes, certificated in any category. (d) Subject Air Transport Association (ATA) of America Code 54, Nacelles/pylons. (e) Unsafe Condition This AD was prompted by a report of heat damage on multiple engine inlets around the 
                        ( print page 12788)
                        engine anti-ice (EAI) duct within the inlet aft compartment due to missing seals between the inner and outer ducts and between the outer duct and the aft compartment. The FAA is issuing this AD to address EAI air leaking into aft compartment exposing inlet components to high temperatures, which could result in damage around the EAI duct. This condition, if not addressed, could lead to reduced structural strength and departure of the inlet from the airplane, resulting in subsequent loss of continued safe flight and landing or injury to occupants from a departed inlet contacting the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions Except as specified by paragraph (h) of this AD: At the applicable times specified in the “Compliance” paragraph of Boeing Alert Requirements Bulletin B787-81205-SB540023-00 RB or B787-81205-SB540024-00 RB, both Issue 001 and both dated September 22, 2023, as applicable, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin B787-81205-SB540023-00 RB or B787-81205-SB540024-00 RB, both Issue 001 and both dated September 22, 2023, as applicable. **Note 1 to paragraph (g):**
                         Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin B787-81205-SB540023-00, dated September 22, 2023, which is referred to in Boeing Alert Requirements Bulletin B787-81205-SB540023-00 RB, Issue 001, dated September 22, 2023. **Note 2 to paragraph (g):**
                         Guidance for accomplishing the actions required by this AD can also be found in Boeing Alert Service Bulletin B787-81205-SB540024-00, dated September 22, 2023, which is referred to in Boeing Alert Requirements Bulletin B787-81205-SB540024-00 RB, Issue 001, dated September 22, 2023. (h) Exceptions to Service Information Specifications (1) Where the “Boeing Recommended Compliance Time” column in the tables under the “Compliance” paragraph of Boeing Alert Requirements Bulletin B787-81205-SB540023-00 RB, Issue 001, dated September 22, 2023, use the phrase “the Issue 001 date of Requirements Bulletin B787-81205-SB540023 RB,” this AD requires using the effective date of this AD. (2) Where the “Boeing Recommended Compliance Time” columns in the tables under the “Compliance” paragraph of Boeing Alert Requirements Bulletin B787-81205-SB540024-00 RB, Issue 001, dated September 22, 2023, use the phrase “the Issue 001 date of Requirements Bulletin B787-81205-SB540024 RB,” this AD requires using the effective date of this AD. (3) Where Boeing Alert Requirements Bulletin B787-81205-SB540023-00 RB, Issue 001, dated September 22, 2023, and Boeing Alert Requirements Bulletin B787-81205-SB540024-00 RB, Issue 001, dated September 22, 2023, specify contacting Boeing for repair instructions, this AD requires doing the repair before further flight, using a method approved in accordance with the procedures specified in paragraph (k) of this AD. (i) Parts Installation Prohibition After accomplishment of all applicable actions required by paragraph (g) of this AD on an airplane, no person may install on that airplane any engine inlet that meets a condition specified in paragraph (i)(1) or (2) of this AD, unless the engine inlet has been inspected and applicable corrective actions taken as specified in Boeing Alert Requirements Bulletin B787-81205-SB540023-00 RB, Issue 001, dated September 22, 2023; or Boeing Alert Requirements Bulletin B787-81205-SB540024-00 RB, Issue 001, dated September 22, 2023. (1) If the engine inlet was installed on an airplane that was dispatched under a dispatch deviation for the operator's existing minimum equipment list (MEL) item 30-21-01-02 or 30-21-01-07 prior to incorporation of Boeing 787 Dispatch Deviation Guide (DDG) 30-21-01-02, as required by this AD. (2) If the engine inlet was installed on an airplane for which dispatch under a dispatch deviation for the operator's existing MEL item 30-21-01-02 or 30-21-01-07 prior to incorporation of Boeing 787 DDG 30-21-01-02, as required by this AD, cannot be determined. (j) 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 the certification office, send it to the attention of the person identified in paragraph (k) of this AD. Information may be emailed to: 
                        *9-ANM-Seattle-ACO-AMOC-Requests@faa.gov.* (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. (k) Related Information For more information about this AD, contact Tak Kobayashi, Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; telephone 206-231-3553; email 
                        *takahisa.kobayashi@faa.gov.* (l) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference 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) Boeing Alert Requirements Bulletin B787-81205-SB540023-00 RB, Issue 001, dated September 22, 2023. (ii) Boeing Alert Requirements Bulletin B787-81205-SB540024-00 RB, Issue 001, dated September 22, 2023. (3) 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.* (4) 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. (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 
                        *fr.inspection@nara.gov.* Issued on February 12, 2024. Victor Wicklund, Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.


[FR Doc. 2024-03254 Filed 2-16-24; 8:45 am] BILLING CODE 4910-13-P