Background \n\n\n\tThe FAA issued AD 2021-02-19, Amendment 39-21402 (86 FR 10171, February 19, 2021) (AD 2021-02-19), for certain Boeing Model 787-8, -9, and -10 airplanes. AD 2021-02-19 required repetitive general visual inspections for disengaged or damaged decompression panels of the bilge barriers located in the forward and aft cargo compartments, reinstallation of disengaged but undamaged panels, and replacement of damaged panels. AD 2021-02-19 was prompted by reports of multiple incidents of torn decompression panels found in the bilge area. The FAA issued AD 2021-02-19 to address the possibility of leakage in the bilge area, which could, in the event of a cargo fire, result in insufficient Halon concentrations to adequately control the fire. This condition, if not addressed, could result in the loss of continued safe flight and landing of the airplane. \n\nActions Since AD 2021-02-19 Was Issued \n\n\n\tSince the FAA issued AD 2021-02-19, the agency received new information indicating that additional airplanes may be subject to the unsafe condition. The applicability of AD 2021-02-19 was limited to airplanes having bilge assemblies with certain decompression panels. Certain other decompression panels were inadvertently omitted from the applicability. The FAA determined that all of the decompression panel part numbers may be subject to damage (tearing) or becoming disengaged. \n\nFAA's Determination \n\n\n\tThe FAA is issuing this AD because the agency determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. \n\nAD Requirements \n\n\n\tThis AD retains all requirements of AD 2021-02-19 and revises the applicability to include all Model 787-8, -9, and -10 airplanes. \n\nExplanation of Serviceable Part \n\n\n\tThis AD requires replacing damaged decompression panels with new or serviceable parts. For purposes of this AD, a serviceable part is airworthy and eligible for installation. While the part does not need to be new, it must conform to type design and be in condition for safe operation. A decompression panel repaired using an approved maintenance program is considered serviceable. \n\nMEL Provision \n\n\n\tParagraph (h) of this AD specifies that if any decompression panel is disengaged or damaged, the airplane may be operated as specified in the operator's existing FAA-approved minimum equipment list (MEL), provided provisions that address the damaged or disengaged decompression panels are included in the MEL. \n\nExplanation of Revised Repetitive Interval \n\n\n\tThe repetitive inspection interval required by AD 2021-02-19 was 120 days. This repetitive interval has been changed in this AD to 4 calendar months to better align the interval with routine operator maintenance scheduling. This change will continue to provide an adequate level of safety. \n\nInterim Action \n\n\n\tThe FAA considers this AD to be an interim action. The manufacturer is currently developing a modification that will address the unsafe condition identified in this AD. Once this modification is developed, approved, and available, the FAA might consider additional rulemaking. \n\nJustification for Immediate Adoption and Determination of the Effective Date \n\n\n\tSection 553(b)(3)(B) of the Administrative Procedure Act (APA) (5 U.S.C. 551 et seq.) authorizes agencies to dispense with notice and comment procedures for rules when the agency, for ''good cause,'' finds that those procedures are ''impracticable, unnecessary, or contrary to the public interest.'' Under this section, an agency, upon finding good cause, may issue a final rule without providing notice and seeking comment prior to issuance. \n\n((Page 20441)) \n\nFurther, section 553(d) of the APA authorizes agencies to make rules effective in less than thirty days, upon a finding of good cause. \n\tAn unsafe condition exists that requires the immediate adoption of this AD without providing an opportunityfor public comments prior to adoption. The FAA has found that the risk to the flying public justifies forgoing notice and comment prior to adoption of this rule because leakage in the bilge area could, in the event of a cargo fire, result in insufficient Halon concentrations to adequately control the fire, and possible loss of continued safe flight and landing of the airplane. Accordingly, notice and opportunity for prior public comment are impracticable and contrary to the public interest pursuant to 5 U.S.C. 553(b)(3)(B). \n\tIn addition, the FAA finds that good cause exists pursuant to 5 U.S.C. 553(d) for making this amendment effective in less than 30 days, for the same reasons the FAA found good cause to forgo notice and comment. \n\nComments Invited \n\n\n\tThe FAA invites you to send any written data, views, or arguments about this final rule. Send your comments to an address listed under ADDRESSES. Include ''Docket No. FAA-2021-0307 and Project Identifier AD-2021-00407-T'' at the beginning of your comments. The most helpful comments reference a specific portion of the final rule, 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 final rule because of those comments. \n\tExcept 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 https://www.regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this final rule. \n\nConfidential Business Information \n\n\n\tCBI 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 AD containcommercial or financial information that is customarily treated as private, that you actually treat as private, and that is relevant or responsive to this AD, 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 AD. Submissions containing CBI should be sent to Brandon Lucero, Aerospace Engineer, Cabin Safety and Environmental Systems Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3569; email: Brandon.Lucero@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. \n\nRegulatory Flexibility Act \n\n\n\tThe requirements of the Regulatory Flexibility Act (RFA) do not apply when an agency finds good cause pursuant to 5 U.S.C. 553to adopt a rule without prior notice and comment. Because the FAA has determined that it has good cause to adopt this rule without notice and comment, RFA analysis is not required. \n\nCosts of Compliance \n\n\n\tThe FAA estimates that this AD affects 222 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: \n\n\n\tEstimated Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost on U.S. \n\tAction Labor cost Parts cost Cost per product operators ---------------------------------------------------------------------------------------------------------------- Repetitive inspections......... 3 work-hours x $85 per $0 $85 per inspection $56,610 per \n\thour = $255 per cycle. inspection cycle. \n\tinspection cycle. ---------------------------------------------------------------------------------------------------------------- \n\n\n\tThe FAA estimates the following costs to do any necessary replacements that would be required based on the results of the inspection. The FAA has no way of determining the number of aircraft that might need these replacements: \n\n\n\tOn-Condition Costs ---------------------------------------------------------------------------------------------------------------- \n\tCost per \n\tAction Labor cost Parts cost product ---------------------------------------------------------------------------------------------------------------- Replacement................................... 1 work-hour x $85 per hour = $85 (*) * $85 ---------------------------------------------------------------------------------------------------------------- \n* The FAA has received no definitive data on which to base the parts cost estimates for the replacements\n\n\tspecified in this AD. \n\nAuthority for This Rulemaking \n\n\n\tTitle 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. \n\tThe 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. \n\nRegulatory Findings \n\n\n\tThis AD will not have federalism implications under Executive Order 13132. This AD will 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. \n\tFor the reasons discussed above, I certify that this AD: \n\n((Page 20442)) \n\n\n\t(1) Is not a ''significant regulatory action'' under Executive Order 12866, and \n\t(2) Will not affect intrastate aviation in Alaska. \n\nList of Subjects in 14 CFR Part 39 \n\n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.