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 Department of Transportation Federal Aviation Administration 14 CFR Part 39
[Docket No. FAA-2021-0685; Project Identifier AD-2021-00432-T]
RIN 2120-AA64
 AGENCY: Federal Aviation Administration (FAA), DOT.
 ACTION: Notice of proposed rulemaking (NPRM).
 SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD) 2020-21-17, which applies to all The Boeing Company Model 757 airplanes. AD 2020-21-17 requires repetitive inspections for skin cracking and shim migration at the upper link drag fittings, diagonal brace cracking, and fastener looseness; and applicable on-condition actions. Since the FAA issued AD 2020-21-17, a determination has been made that the compliance times for certain groups are not adequate. This proposed AD would retain the requirements of AD 2020-21-17 with reduced compliance times for certain airplane groups. 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 October 25, 2021.
 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 
                        *https://www.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. 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; internet 
                        *https://www.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 
                        *https://www.regulations.gov*
                         by searching for and locating Docket No. FAA-2021-0685. Examining the AD Docket You may examine the AD docket at 
                    *https://www.regulations.gov*
                     by searching for and locating Docket No. FAA-2021-0685; 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.
 FOR FURTHER INFORMATION CONTACT: David Truong, Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5224; fax: 562-627-5210; email: 
                        *david.truong@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-2021-0685; Project Identifier AD-2021-00432-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 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 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 David Truong, Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5224; fax: 562-627-5210; email: 
                    *david.truong@faa.gov.*
                     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 issued AD 2020-21-17, Amendment 39-21290 (85 FR 79418, December 10, 2020) (AD 2020-21-17), for all The Boeing Company Model 757 airplanes. AD 2020-21-17 was prompted by reports of bolt rotation in the engine drag fitting joint and fastener heads; an inspection of the fastener holes revealed that cracks were found in the skin, and certain inspections revealed multiple cracks found in the drag fitting at fastener holes. AD 2020-21-17 requires repetitive inspections for skin cracking and shim migration at the upper link drag fittings, diagonal brace cracking, and fastener looseness; and applicable on-condition actions. The agency issued AD 2020-21-17 to address cracking in the wing upper skin and forward drag fittings, which could lead to a compromised upper link and reduced structural integrity of the engine strut. Actions Since AD 2020-21-17 Was Issued Since the FAA issued AD 2020-21-17, a determination has been made that the compliance times for group 3 and 4 airplanes are not adequate. An operator reported that during performance of the inspections required by AD 2020-21-17, the wing upper skin panel was found cracked at hole #2. The airplane had 19,432 total flight cycles and was a group 3 airplane (Model 757-200 airplane with Rolls-Royce engines and non-cold worked skin). Therefore, because of similar airplane 
                    ( print page 50486)
                    configurations, the compliance times for group 3 and 4 airplanes have been reduced to maintain structural integrity of 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 757-57A0073 RB, Revision 2, dated March 1, 2021. This service information specifies procedures for repetitive general visual and detailed inspections for loose fasteners, skin cracking, and shim migration at the upper link drag fittings, and for cracking in the diagonal brace and diagonal brace fittings; repetitive open-hole high frequency eddy current inspections for cracking of the fastener holes and loose bolt holes; and applicable on-condition actions. On-condition actions include installing the upper link and upper link pins; replacing drag fittings; installing bolts, washers, and nuts; performing a torque check of fasteners on the affected shims; trimming affected shims and applying chemical conversion coating on the shims, fillet seal, and drag fittings; and repairing cracks, migrated shims, mistorqued bolts, and loose fasteners. 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 Although this proposed AD does not explicitly restate the requirements of AD 2020-21-17, this proposed AD would retain all of the requirements of AD 2020-21-17. Those requirements are referenced in the service information identified previously, which, in turn, is referenced in paragraph (g) of this proposed AD. This proposed AD would reduce the compliance times for certain airplanes. This proposed AD would require accomplishing the actions specified in the service information already described, 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 
                    *https://www.regulations.gov*
                     by searching for and locating Docket No. FAA-2021-0685. Costs of Compliance The FAA estimates that this AD, if adopted as proposed, would affect 450 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.
                             operatorsRepetitive HFEC inspections
85 work-hours × $85 per hour = $7,225 per inspection cycle
$0
$7,225 per inspection cycle
$3,251,250 per inspection cycle.
 The FAA has received no definitive data on which to base the cost estimates for the on-condition actions 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
 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: a.Removing Airworthiness Directive (AD) 2020-21-17, Amendment 39-21290 ( 85 FR 79418, December 10, 2020), and b.Adding the following new AD: **The Boeing Company:**
                         Docket No. FAA-2021-0685; Project Identifier AD-2021-00432-T. (a) Comments Due Date The FAA must receive comments on this airworthiness directive (AD) by October 25, 2021. (b) Affected ADs This AD replaces AD 2020-21-17, Amendment 39-21290 (85 FR 79418, December 10, 2020) (AD 2020-21-17). (c) Applicability This AD applies to all The Boeing Company Model 757-200, -200PF, -200CB, and -300 series airplanes, certificated in any category.
                        ( print page 50487) (d) Subject Air Transport Association (ATA) of America Code 57, Wings. (e) Unsafe Condition This AD was prompted by reports of bolt rotation in the engine drag fitting joint and fastener heads and cracks found in the skin of the fastener holes, and the need to reduce the compliance time for certain groups. The FAA is issuing this AD to address cracking in the wing upper skin and forward drag fittings, which could lead to a compromised upper link and reduced structural integrity of the engine strut, and possible separation of a strut and engine from the airplane during flight. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) New 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 757-57A0073 RB, Revision 2, dated March 1, 2021, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin 757-57A0073 RB, Revision 2, dated March 1, 2021. Note 1 to paragraph (g): Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin 757-57A0073, Revision 2, dated March 1, 2021, which is referred to in Boeing Alert Requirements Bulletin 757-57A0073 RB, Revision 2, dated March 1, 2021. (h) Exceptions to Service Information Specifications (1) Where Boeing Alert Requirements Bulletin 757-57A0073 RB, Revision 2, dated March 1, 2021 uses the phrase “the Original Issue date of Requirements Bulletin 757-57A0073 RB,” this AD requires using September 10, 2018 (the effective date of AD 2018-16-05, Amendment 39-19345 (83 FR 38250, August 6, 2018)). (2) Where the “Effectivity” paragraph and the Condition and Compliance Time columns of the tables in the “Compliance” paragraph of Boeing Alert Requirements Bulletin 757-57A0073 RB, Revision 2, dated March 1, 2021, uses the phrase “the Revision 1 date of Requirements Bulletin 757-57A0073 RB date of this service bulletin,” this AD requires using January 14, 2021 (the effective date of AD 2020-21-17). (3) Where the “Effectivity” paragraph and the Condition and Compliance Time columns of the tables in the “Compliance” paragraph of Boeing Alert Requirements Bulletin 757-57A0073 RB, Revision 2, dated March 1, 2021, uses the phrase “the Revision 2 date of Requirements Bulletin 757-57A0073 RB,” this AD requires using the effective date of this AD. (4) Where Boeing Alert Requirements Bulletin 757-57A0073 RB, Revision 2, dated March 1, 2021, specifies contacting Boeing for repair instructions: This AD requires doing the repair using a method approved in accordance with the procedures specified in paragraph (j) of this AD. (i) Credit for Previous Actions (1) This paragraph provides credit for the actions specified in paragraph (g) of this AD, except for the open-hole high frequency eddy current inspections at fastener locations 11-18, if those actions were performed before the effective date of this AD using Boeing Alert Requirements Bulletin 757-57A0073 RB, dated July 14, 2017. (2) This paragraph provides credit for the actions specified in paragraph (g) of this AD, if those actions were performed before the effective date of this AD using Boeing Alert Requirements Bulletin 757-57A0073 RB, Revision 1, dated August 1, 2019. This service information is not incorporated by reference in this AD. (j) Alternative Methods of Compliance (AMOCs) (1) The Manager, Los Angeles ACO 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 Related Information. Information may be emailed to: 
                        *9-ANM-LAACO-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, Los Angeles ACO 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 2020-21-17 are approved as AMOCs for the corresponding provisions of Boeing Alert Requirements Bulletin 757-57A0073 RB, Revision 2, dated March 1, 2021, that are required by paragraph (g) of this AD. (k) Related Information (1) For more information about this AD, contact David Truong, Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5224; fax: 562-627-5210; email: 
                        *david.truong@faa.gov.* (2) 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; internet 
                        *https://www.myboeingfleet.com.*
                         You may view this referenced 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. Issued on August 12, 2021. Lance T. Gant, Director, Compliance & Airworthiness Division, Aircraft Certification Service.


[FR Doc. 2021-19460 Filed 9-8-21; 8:45 am] BILLING CODE 4910-13-P