Airworthiness Directives; The Boeing Company Airplanes

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Federal RegisterFeb 24, 2021
86 Fed. Reg. 11158 (Feb. 24, 2021)

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (SNPRM); reopening of comment period.

SUMMARY:

The FAA is revising an earlier proposal for certain The Boeing Company Model 767-200, -300, -300F, and -400ER series airplanes. This action revises the notice of proposed rulemaking (NPRM) by adding airplanes to the applicability and proposing to require revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations. The FAA is proposing this airworthiness directive (AD) to address the unsafe condition on these products. Since these actions would impose an additional burden over that in the NPRM, the FAA is reopening the comment period to allow the public the chance to comment on these changes.

DATES:

The comment period for the NPRM published in the Federal Register on November 7, 2019 (84 FR 60007), is reopened.

The FAA must receive comments on this SNPRM by April 12, 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 SNPRM, 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 on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2019-0862.

Examining the AD Docket

You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2019-0862; 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 SNPRM, any comments received, and other information. The street address for Docket Operations is listed above.

FOR FURTHER INFORMATION CONTACT:

Wayne Lockett, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3524; email: wayne.lockett@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-2019-0862; Product Identifier 2019-NM-121-AD” 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 SNPRM 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 SNPRM, 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 SNPRM. Submissions containing CBI should be sent to Wayne Lockett, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3524; email: wayne.lockett@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.

Discussion

The FAA issued an NPRM to amend 14 CFR part 39 by adding an AD that would apply to certain The Boeing Company Model 767-200, -300, -300F, and -400ER series airplanes. The NPRM published in the Federal Register on November 7, 2019 (84 FR 60007). The NPRM was prompted by a determination that new or more restrictive airworthiness limitations are necessary. The NPRM proposed to require revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations.

Actions Since the NPRM Was Issued

Since the FAA issued the NPRM, the manufacturer has issued new or more restrictive airworthiness limitations, and the FAA has determined it is necessary to mandate those limitations. In addition, the FAA has determined that those new limitations apply to more airplanes than were included in the NPRM.

Comments

The FAA gave the public the opportunity to comment on the NPRM. The following presents the comments received on the NPRM and the FAA's response to each comment.

Request To Clarify Compliance Time for Paragraph (h)(2) of the Proposed AD

Boeing, American Airlines, and United Parcel Service (UPS) requested that the FAA clarify the compliance time for the actions described in paragraph (h)(2) of the proposed AD. The commenters noted that no compliance time had been given for obtaining the revised inspection intervals as directed in that paragraph, and recommended a period of 24 months.

The FAA agrees to clarify that for any horizontal stabilizer pivot fitting lug (SSI 55-10-I13A) on which a lug bore oversize repair has been accomplished, the compliance time for obtaining revised inspection intervals is within 24 months after the effective date of this AD, which is the compliance time for revising the maintenance or inspection program as specified in paragraph (g) of this proposed AD. The FAA has revised paragraph (h)(2) of this proposed AD to include the specified compliance time.

Request To Clarify New Inspection Intervals

American Airlines asked that paragraph (h)(2) of the proposed AD be further clarified to state that the lug bore oversize repairs must be re-evaluated and revised intervals must be obtained, as applicable. American Airlines reasoned that revised inspection intervals might not be required after re-evaluation, based on language in the Differences Between This Proposed AD and the Service Information section of the proposed AD that stated repairs “will require further evaluation to determine the applicable inspection interval to be incorporated.”

The FAA agrees with the commenter's request. The FAA acknowledges that upon further evaluation of the repair, it is possible certain intervals might not be revised, and the inspection program provided in the original approved alternative method of compliance (AMOC) for that repair would still be acceptable. The FAA has revised paragraph (h)(2) of this proposed AD to clarify that the requirement is to “re-evaluate the repair and obtain revised inspection intervals, as applicable.”

Request To Modify Applicability Paragraph of the Proposed AD

Aviation Partners Boeing (APB) requested that paragraph (c) of the proposed AD be amended to include language advising that a “change in product” AMOC approval may be needed for airplanes with Supplemental Type Certificate (STC) ST01920SE installed. APB stated that installation of STC ST01920SE affects the ability to accomplish some of the actions required by the proposed AD. APB noted that it is in the process of revising the APB airworthiness limitations (AWL) and damage tolerance rating (DTR) Check Form Supplements to define the alternative inspections and/or inspection intervals required for the structural AWLs affected by the revised Boeing service information. APB noted that its documents are “alternative” to the Boeing service information and that APB planned to apply for an AMOC to the proposed AD if it is adopted as a final rule.

The FAA agrees with the request to add a paragraph providing the specified information. The FAA has redesignated paragraph (c) of the proposed AD (in the NPRM) as paragraph (c)(1) of this proposed AD and added paragraph (c)(2) to this proposed AD to advise operators that installation of STC ST01920SE affects the ability to accomplish some of the actions required by this AD, and that an AMOC may be required in order to comply with the requirements of 14 CFR 39.17.

Additionally, the FAA emphasizes that for any airplane that is modified by an STC that affects any structurally significant item (SSI) inspections, an AMOC approval request is necessary to comply with the requirements of 14 CFR 39.17.

Request To Clarify the Intent of Paragraph (l)(4) of the Proposed AD

American Airlines requested that the FAA clarify the intent of the last sentence of paragraph (l)(4) of the proposed AD and confirm that operators are not required to re-notify principal inspectors, as specified in paragraph (l)(2) of the proposed AD, or to revise previously approved AMOCs. The commenter stated that the final sentence of the paragraph seems to nullify the guidance of the previous sentence.

The FAA agrees to clarify the intent of paragraph (l)(4) of this proposed AD. The intent of paragraph (l)(4) of this proposed AD is to allow previously approved AMOCs only for repairs and alterations. The last sentence of paragraph (l)(4) of this proposed AD is intended to advise that revisions of the AWL prior to the July 2020 revision, that were approved as an AMOC to AD 2014-14-04, Amendment 39-17899 (79 FR 44672, August 1, 2014) (AD 2014-14-04), cannot be used to comply with any actions in this proposed AD. In addition, for existing AMOCs to AD 2003-18-10, Amendment 39-13301 (68 FR 53503, September 11, 2003) (AD 2003-18-10), and AD 2014-14-04, operators are not required to re-notify FAA personnel in accordance with paragraph (l)(2) of this proposed AD. Finally, existing AMOCs to ADs 2003-18-10 and 2014-14-04 are not required to be revised to specifically reference this proposed AD. This proposed AD has not been changed with regard to this request.

Request To Clarify Paragraph (l)(5) of the Proposed AD

American Airlines requested clarification of the compliance time for the requirements of paragraph (l)(5) of the proposed AD. American Airlines asserted that for a recently accomplished repair approved by the The Boeing Company Organization Designation Authorization (ODA) for Stage I, and currently pending damage tolerance evaluation (DTE) (Stage II/III), the compliance time should align with the standard Boeing DTE timeline of 24 months from Stage I approval to completion of Stage I, II, and III approval. American Airlines also requested confirmation that repair approvals obtained in accordance with paragraph (l)(5) of the proposed AD do not require reference to the proposed AD, since those approvals were issued prior to the effective date of this AD.

The FAA does not agree with the request to allow repairs in progress to use the 24-month Boeing DTE timeline. To use the provisions specified in paragraph (l)(5) of this proposed AD, the repair must be completed before the effective date of this AD. Repairs accomplished before the effective date of this AD that do not meet the conditions specified in paragraphs (l)(5)(ii) and (iii) of this proposed AD have until when the next AD-required inspection is due to obtain any AMOC that may be needed.

Regarding the repair approval request, the FAA confirms that the approvals do not need to refer to this AD. The FAA has not changed this proposed AD regarding this issue.

Request To Clarify “Next Wing Tank Entry”

UPS requested clarification of the term “next wing tank entry” as used in paragraph (h)(1) of the proposed AD. The commenter stated that the term is unnecessary and adds confusion.

The FAA agrees with the request to clarify what was meant by “next wing tank entry.” The intent is to allow accomplishment of the sealant removal task prior to the next accomplishment of the specific maintenance planning document task, and not during a fuel tank entry for non-AWL-related reasons. The FAA has removed “next fuel tank entry” from the exception in paragraph (h)(1) of this proposed AD and replaced it with “next accomplishment of the specific Maintenance Planning Document (MPD) task.”

Request To Change the Grace Period in Paragraph (h)(1) of the Proposed AD

UPS requested that the grace period in paragraph (h)(1) of the proposed AD be changed from 6 years to 8 years. UPS stated it considers that the FAA is providing accommodations for the tasks that can be repeated at intervals up to 4C, considering an 18-month 1C check interval. However, UPS noted that per Subsection B, “Structural Inspections” of Boeing 767-200/300/300F/400ER Airworthiness Limitations (AWLs), D622T001-9-01, dated July 2020, a 1C check is defined as 3,000 flight cycles, or 24 months, or 9,000 flight hours, whichever occurs first. UPS stated that an 8-year grace period is more acceptable to meet the intent of the accommodation by the FAA.

The FAA disagrees with the requested grace period of “not to exceed 8 years” because the 6-year grace period does meet the FAA's intent to provide a grace period for certain instructions to do certain actions, In addition, the commenter did not provide adequate supporting documentation to justify the escalation. All MPD tasks listed in the Excess Sealant Table of the AWL document have a baseline repetitive inspection interval of 6 years. Even though these tasks may have the option for escalation of the inspection intervals, each operator addresses escalation differently, and may request an escalation using the AMOC process. The FAA has not changed this proposed AD regarding this issue.

Request To Allow an Acceptable Method of Compliance for Certain Tasks

FedEx Express requested that the FAA incorporate Boeing 767-200/300/300F/400ER Airworthiness Limitations—Line Number Specific, D622T001-9-02, dated April 2019, as another acceptable method of compliance for the proposed AD. The commenter noted that certain requirements of Boeing 767-200/300/300F/400ER Airworthiness Limitations (AWLs), D622T001-9-01, dated June 2019, cannot be accomplished due to specific line number differences in configuration as a result of Material Review Board (MRB) actions.

The FAA agrees with the request. However, the FAA notes that Boeing has released a newer version of the document mentioned by the commenter. The FAA has therefore added paragraph (h)(4) to this proposed AD to specify that revising the existing maintenance or inspection program, as applicable, to incorporate the information specified in Boeing 767-200/300/300F/400ER Airworthiness Limitations—Line Number Specific, D622T001-9-02, dated August 2020, is an acceptable method of compliance with paragraph (g) of this proposed AD for the tasks specified in that document only.

Related Service Information Under 1 CFR Part 51

The FAA reviewed the following service information, which describes airworthiness limitations for structural inspections and structural safe life limits among other limitations. These documents are distinct since they apply to different configurations.

  • Boeing 767-200/300/300F/400ER Airworthiness Limitations (AWLs), D622T001-9-01, dated July 2020.
  • Boeing 767-200/300/300F/400ER Airworthiness Limitations—Line Number Specific, D622T001-9-02, dated August 2020.

The FAA also reviewed Boeing 767-200/300/300F/400ER Damage Tolerance Rating (DTR) Check Form Document, D622T001-DTR, dated February 2020. This service information includes the DTR check forms and the procedure for their use.

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.

FAA's Determination

The FAA is proposing this AD because the agency evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. Certain changes described above expand the scope of the NPRM. As a result, the FAA has determined that it is necessary to reopen the comment period to provide additional opportunity for the public to comment on this SNPRM.

Proposed Requirements of This SNPRM

This SNPRM would require revising the existing maintenance or inspection program, as applicable, to incorporate new or more restrictive airworthiness limitations. This proposed AD also would require sending the inspection results to Boeing.

Costs of Compliance

The FAA estimates that this AD affects 542 airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD:

The FAA has determined that revising the existing maintenance or inspection program takes an average of 90 work-hours per operator, although the FAA recognizes that this number may vary from operator to operator. In the past, the FAA has estimated that this action takes 1 work-hour per airplane. Since operators incorporate maintenance or inspection program changes for their affected fleet(s), the FAA has determined that a per-operator estimate is more accurate than a per-airplane estimate. Therefore, the FAA estimates the total cost per operator to be $7,650 (90 work-hours × $85 per work-hour).

Estimated Costs of On-Condition Actions

Action Labor cost Parts cost Cost per product
Reporting 1 work-hour × $85 per hour = $85 $0 $85

Paperwork Reduction Act

A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a current valid OMB control number. The control number for the collection of information required by this proposed AD is 2120-0056. The paperwork cost associated with this proposed AD has been detailed in the Costs of Compliance section of this document and includes time for reviewing instructions, as well as completing and reviewing the collection of information. Therefore, all reporting associated with this proposed AD is mandatory. Comments concerning the accuracy of this burden and suggestions for reducing the burden should be directed to Information Collection Clearance Officer, Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524.

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
[Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive:

The Boeing Company: Docket No. FAA-2019-0862; Product Identifier 2019-NM-121-AD.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) action by April 12, 2021.

(b) Affected ADs

This AD affects AD 2014-14-04, Amendment 39-17899 (79 FR 44672, August 1, 2014) (AD 2014-14-04).

(c) Applicability

(1) This AD applies to The Boeing Company Model 767-200, -300, -300F, and -400ER series airplanes, certificated in any category, line numbers 1 through 1218 inclusive.

(2) Installation of Supplemental Type Certificate (STC) ST01920SE affects the ability to accomplish some of the actions required by this AD. Therefore, for airplanes on which STC ST01920SE is installed, a “change in product” alternative method of compliance (AMOC) approval may be necessary to comply with the requirements of 14 CFR 39.17.

(d) Subject

Air Transport Association (ATA) of America Code 27, Flight Controls; 52, Doors; 53, Fuselage; 54, Nacelles/pylons; 55, Stabilizers; 57, Wings.

(e) Unsafe Condition

This AD was prompted by a determination that new or more restrictive airworthiness limitations (AWLs) are necessary. The FAA is issuing this AD to address inadequate AWL and damage tolerance rating (DTR) values in the maintenance or inspection program that reduce the probability of detection for foreseeable fatigue cracking of structurally significant items (SSIs). This condition, if not addressed, could result in the loss of limit load capability of an SSI as well as loss of continued safe flight and landing of the airplane.

(f) Compliance

Comply with this AD within the compliance times specified, unless already done.

(g) Maintenance or Inspection Program Revision

Within 24 months after the effective date of this AD, revise the existing maintenance or inspection program, as applicable, to incorporate the information specified in Boeing 767-200/300/300F/400ER Airworthiness Limitations (AWLs), D622T001-9-01, dated July 2020; and Boeing 767-200/300/300F/400ER Damage Tolerance Rating (DTR) Check Form Document, D622T001-DTR, dated February 2020. Except as specified in paragraph (h) of this AD, the initial compliance time for doing the tasks is at the time specified in Boeing 767-200/300/300F/400ER Airworthiness Limitations (AWLs), D622T001-9-01, dated July 2020; and Boeing 767-200/300/300F/400ER Damage Tolerance Rating (DTR) Check Form Document, D622T001-DTR, dated February 2020; or within 24 months after the effective date of this AD; whichever occurs later.

(h) Exceptions

(1) Where Boeing 767-200/300/300F/400ER Airworthiness Limitations (AWLs), D622T001-9-01, dated July 2020, specifies compliance times (“thresholds”) for wing tank sealant removal and ensuring sealant location limits are met, these actions must be accomplished within the compliance times specified in Boeing 767-200/300/300F/400ER Airworthiness Limitations (AWLs), D622T001-9-01, dated July 2020; or at or before the next accomplishment of the specific Maintenance Planning Document (MPD) task, but no later than 6 years after the effective date of this AD; whichever occurs later.

(2) For any horizontal stabilizer pivot fitting lug (SSI 55-10-I13A) on which a lug bore oversize repair has been accomplished: Within 24 months after the effective date of this AD, re-evaluate the repair and obtain revised inspection intervals, as applicable, in accordance with the procedures specified in paragraph (l) of this AD.

(3) Where Boeing 767-200/300/300F/400ER Airworthiness Limitations (AWLs), D622T001-9-01, dated July 2020; and Boeing 767-200/300/300F/400ER Damage Tolerance Rating (DTR) Check Form Document, D622T001-DTR, dated February 2020; specify to submit reports within 10 days, those reports may be submitted within 10 days after the airplane is returned to service.

(4) For airplanes having line numbers identified in Boeing 767-200/300/300F/400ER Airworthiness Limitations—Line Number Specific, D622T001-9-02, dated August 2020: Revising the existing maintenance or inspection program, as applicable, to incorporate the information specified in Boeing 767-200/300/300F/400ER Airworthiness Limitations—Line Number Specific, D622T001-9-02, dated August 2020, is an acceptable method of compliance with paragraph (g) of this AD for the tasks specified in Boeing 767-200/300/300F/400ER Airworthiness Limitations—Line Number Specific, D622T001-9-02, dated August 2020, only. The initial compliance time for doing the tasks is at the time specified in Boeing 767-200/300/300F/400ER Airworthiness Limitations—Line Number Specific, D622T001-9-02, dated August 2020; or within 24 months after the effective date of this AD; whichever occurs later. For all other tasks specified in the service information identified in paragraph (g) of this AD, the requirements of paragraph (g) of this AD remain fully applicable and must be complied with.

(i) No Alternative Actions or Intervals

After the existing maintenance or inspection program has been revised as required by paragraph (g) of this AD, no alternative actions (e.g., inspections) or intervals may be used unless the actions or intervals are approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (l) of this AD.

(j) Terminating Action for AD 2014-14-04

Accomplishing the actions required by this AD terminates all requirements of AD 2014-14-04.

(k) Paperwork Reduction Act Burden Statement

A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to a penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a current valid OMB Control Number. The OMB Control Number for this information collection is 2120-0056. Public reporting for this collection of information is estimated to be approximately 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. All responses to this collection of information are mandatory. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to Information Collection Clearance Officer, Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524.

(l) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Seattle 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 paragraph (m)(1) 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, Seattle ACO Branch, 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 for repairs and alterations approved previously for AD 2003-18-10, Amendment 39-13301 (68 FR 53503, September 11, 2003) (AD 2003-18-10), and AD 2014-14-04 are approved as AMOCs for the corresponding actions specified in this AD. All other AMOCs for AD 2003-18-10 and AD 2014-14-04 are not approved as AMOCs for this AD.

(5) Repairs done before the effective date of this AD that meet the conditions specified in paragraphs (l)(5)(i), (ii), and (iii) of this AD are acceptable methods of compliance for the repaired area where the inspections of the baseline structure cannot be accomplished.

(i) The repair was approved under both 14 CFR 25.571 and 14 CFR 26.43(d) by The Boeing Company ODA that has been authorized by the Manager, Seattle ACO Branch, FAA, to make those findings.

(ii) The repair approval provides an inspection program (inspection threshold, method, and repetitive interval).

(iii) Operators revised their maintenance or inspection program, as applicable, to include the inspection program (inspection threshold, method, and repetitive interval) for the repair.

(m) Related Information

(1) For more information about this AD, contact Wayne Lockett, Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3524; email: wayne.lockett@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 January 20, 2021.

Gaetano A. Sciortino,

Deputy Director for Strategic Initiatives, Compliance & Airworthiness Division, Aircraft Certification Service.

[FR Doc. 2021-03595 Filed 2-23-21; 8:45 am]

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