U .S. Department of Transportation Federal Aviation Administration Advisory Circular Subject: Standardized Procedures for Obtaining Approval of Data Used in the Performance of Major Repairs and Major Alterations Date: 6/23/26 AC No: 43-210A Initiated by: AFS-300 Change: 2
1. PURPOSE OF THIS ADVISORY CIRCULAR (AC). This AC describes a standardized procedure for requesting approval of technical data associated with major repairs/major alterations. This AC also provides information that can help determine if a proposed repair/alteration requires approved data, guidance, and standardized procedures for obtaining field approval (or approval by other means) of data, and instructions for completing the field approval checklist.
2. PRINCIPAL CHANGES. This change adds regulatory and statutory reference citations to the guidance contained in this document, updates language to align with guidance policy, updates hyperlinks to references, and makes other editorial changes.
PAGE CONTROL CHART Remove Pages Dated Insert Pages Dated Page i 8/17/16 Page i 6/23/26 Pages ii and iii 5/31/18 Pages ii and iii 6/23/26 Pages 1 and 2 5/31/18 Pages 1 and 2 6/23/26 Page 3 8/17/16 Page 3 6/23/26 Pages 4 and 5 5/31/18 Pages 4 and 5 6/23/26 Pages 6 and 7 8/17/16 Pages 6 and 7 6/23/26 Page 8 5/31/18 Page 8 6/23/26 Page 10 5/31/18 Page 10 6/23/26 Page 12 5/31/18 Page 12 6/23/26 Page 13 8/17/16 Page 13 6/23/26 Page 16 8/17/16 Page 16 6/23/26 Page 17 5/31/18 Page 17 6/23/26 Pages 18 thru 20 8/17/16 Pages 18 thru 21 6/23/26 Pages 21 and 22 5/31/18 Pages 22 and 23 6/23/26 Page 24 5/31/18 Page 25 6/23/26 Page A-5 8/17/16 Page A-5 6/23/26 R obert Reckert for Hugh Thomas Executive Director, Flight Standards Service
U.
S. Department of Transportation Federal Aviation Administration Advisory Circular Subject: Standardized Procedures for Obtaining Approval of Data Used in the Performance of Major Repairs and Major Alterations Date: 8/17/16 AC No: 43-210A Initiated by: AFS-300 Change:
This advisory circular (AC) describes a standardized procedure for requesting approval of technical data associated with major repairs/major alterations. This AC also provides information that can help determine if a proposed repair/alteration requires approved data, guidance, and standardized procedures for obtaining field approval (or approval by other means) of data, and instructions for completing the field approval checklist. This is a guidance document. Its content is not legally binding in its own right and will not be relied upon by the Department as a separate basis for affirmative enforcement action or other administrative penalty. Conformity with the guidance document is voluntary only. Nonconformity will not affect rights and obligations under existing statutes and regulations. This AC does not change regulatory requirements and does not authorize changes in, or deviations from, regulatory requirements. This AC establishes an acceptable means, but not the only means, of compliance. Since the guidance material presented in this AC is not regulatory, terms having a mandatory definition, such as “shall” and “must,” etc., as used in this AC, apply either to the reiteration of a regulation itself, or to an applicant who chooses to follow a prescribed method of compliance without deviation.
Note: As a result of the 2023 Aircraft Certification Service (AIR) reorganization, Aircraft Certification Offices (ACO) are now Certification Branches. For more information, refer to https://www.faa.gov/about/office_org/headquarters_offices/a vs/offices/air/field_office.
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CONTENTS Paragraph Page
1 Introduction1
1.1 Purpose of This Advisory Circular (AC)1
1.2 Audience1
1.3 Where You Can Find This AC1
1.4 What This AC Cancels1
1.5 Regulatory Basis1
1.6 Repair and Alteration Classification2
1.7 Responsibility for Obtaining Data2
1.8 General Information2
2 Data2
2.1 Definition of Data as it Relates to a Repair or Alteration2
2.2 Classification of Technical Data2
3 Field Approval Process and Data Approval7
3.1 General Information7
3.2 Conduct Research7
3.3 Evaluate the Data9
3.4 Perform Repair or Alteration13
4 Flight Manual Supplements16
4.1 General Information16
4.2 AFMs16
4.3 Manual Supplements16
4.4 Format and Content16
4.5 Supplement Information Approval17
4.6 AIR Certification Branch Approval Process17
4.7 Additional AFMS Considerations18
Maintenance Information18
5.1 Purpose of Maintenance Information for a Major Repair or Major Alteration18
5.2 Benefits of Providing Maintenance Information for a Major Repair or Major
Alteration19
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5.3 Maintenance Information as Part of the Major Repair or Major Alteration Data
Package19
5.4 Maintenance Information Under the Civil Air Regulations (CAR)19
5.5 Maintenance Information Development20
5.6 Maintenance Information Content20
6 Administrative Information23
6.1 Acronyms23
6.2 Related FAA Orders and ACs (current editions)24
6.3 Obtaining Copies of Referenced Documents and This AC25
6.4 AC Feedback Form25
Appendix A. Instructions for Completing the F ield Approval ChecklistA-1
Appendix B. Instructions for Completing the Compliance ChecklistB-1
List of Figures Figure 2-1. Possible Resources for Approved Data Relevant to Major Repairs or Major
Alterations6
Figure 3-1. Field Approval Process14
Figure 3-2. Determination of Major or Minor Alteration or Repair15
Figure 5-1. Major Repair or Major Alteration Maintenance Information Checklist22
Figure A-1. Field Approval ChecklistA-3
Figure B-1. Compliance Checklist FormatB-1
1 1 INTRODUCTION.
1.1 Purpose of This Advisory Circular (AC). This AC describes a standardized procedure for requesting approval of technical data associated with major repairs/major alterations.
This AC also provides:
1. Information that can help determine if a proposed repair/alteration requires approved data;
2. Guidance and standardized procedures for obtaining field approval, or approval by other means, of data; and
3. Instructions for completing the field approval checklist (see Appendix A, Instructions for Completing the Field Approval Checklist).
1.2 Audience. This AC applies to applicants who request data approval for a major repair or major alteration.
1.3 Where You Can Find This AC. You can find this AC on the Federal Aviation Administration’s (FAA) website at https://www.faa.gov/regulations_policies/advisory_cir culars and the Dynamic Regulatory System (DRS) at https://drs.faa.gov.
1.4 What This AC Cancels. This AC cancels AC 43-210, Standardized Procedures for Requesting Field Approval of Data, Major Alterations, and Repairs, dated February 17, 2004.
1.5 Regulatory Basis. Title 14 of the Code of Federal Regulations (14 CFR) § 43.7 specifies persons authorized to approve an aircraft or aircraft component for return to service after maintenance, preventative maintenance, rebuilding, or alteration. For major repairs or major alterations, the work must be done in accordance with technical data approved by the Administrator. The following CFR references require the use of this data:
1. Title 14 CFR §§ 43.7(d) and 43.17(e)(2);
2. Title 14 CFR § 65.95(a)(1);
3. Title 14 CFR § 121.379(b);
4. Title 14 CFR § 135.437(b); and
5. Title 14 CFR § 145.201(c)(2).
Title 14 CFR § 1.1 defines major repairs and major alterations. In addition, 14 CFR part 43 appendix A, paragraph (a) further defines what constitutes a major alteration. In a similar manner, 14 CFR part 43 appendix A, paragraph (b) further defines what constitutes a major repair. Title 14 CFR § 1.1 provides that a minor alteration is an alteration that is not major and, likewise, a minor repair is one that is not a major repair.
1.6 Repair and Alteration Classification.
1.6.1 Only those persons with 14 CFR § 43.7 authorization may approve an aircraft, airframe, engine, propeller, appliance, or component part for return to service after the performance of a repair or alteration. You must perform major repairs and major alterations using technical data approved by the Administrator. You may perform minor repairs and alterations using technical data acceptable to the Administrator. This AC includes flowcharts (Figures 3-1, Field Approval Process, and 3-2, Determination of Major or Minor Alteration or Repair) to help classify a repair/alteration.
1.6.2 For assistance, you may use the Major Repair and Alteration Data Approval (MRADA) Job Aid at https://drs.faa.gov/browse/OTHER_JOB_AIDS/doctypeDetails. The job aid lists types of alterations and how applicants typically classify them.
1.7 Responsibility for Obtaining Data. It is the responsibility of the person intending on performing the major repair/major alteration to obtain, organize, and submit data to the approving authority for review and approval.
1.8 General Information. For the purpose of this AC, the use of the term “aviation safety inspector (ASI)” includes Flight Standards Designated Airworthiness Representatives— Maintenance (DAR-T) authorized to issue data approvals in support of a major repair or alteration when performing work in accordance with FAA Order 8000.95, Designee Management Policy. Also, for the purposes of this guidance, Aircraft Flight Manual Supplement (AFMS) includes Rotorcraft Flight Manual Supplement (RFMS) and Supplemental Aircraft Flight Manual (SAFM).
2 DATA.
2.1 Definition of Data as it Relates to a Repair or Alteration. In its broadest sense, data is recorded information. Data supporting a repair or alteration consists of drawings and specifications, including a list of drawings and specifications, which define configuration and design features of a particular article, repair, or alteration. Data may be classified relative to its type or its approval status.
2.2 Classification of Technical Data.
2.2.1 Types of Data.
2.2.1.1 Descriptive Data. Descriptive data describes the design of the repair or alteration. It should include references to installation methods, materials, fabrication processes, dimensions, and tolerances. It may also include function and how the alteration is appropriate to the aircraft. Descriptive data typically includes:
1. Drawings and specifications.
Note: We accept sketches, photos, or pictures as descriptive data when it is appropriate, such as for certain one-time approvals.
2. Information on dimensions, materials, and processes.
3. Airworthiness limitations (AL), if applicable.
4. Documents required by the airworthiness requirements such as instructions for continued airworthiness (ICA) and airplane or Rotorcraft Flight Manuals (RFM).
2.2.1.2 Substantiating Data. Substantiating data shows that the design complies with the applicable regulations and that all appropriate technical considerations have been addressed. Examples of substantiating data can be: test results, computations, and other information necessary to show that descriptive data meets the applicable requirements. Such substantiating data, when approved, forms the basis of declaring conformity to the type design or applicable airworthiness standards.
2.2.2 Approval Status.
2.2.2.1 Approved Data. Approved data is data approved by the FAA. The term “approved” is based on 14 CFR § 1.1, which states, “Approved, unless used with reference to another person, means approved by the FAA or any person to whom the FAA has delegated its authority in the matter concerned, or approved under the provisions of a bilateral agreement between the United States and a foreign country or jurisdiction.” For the FAA ASI, “approved” or “approved by” means the item (e.g., data; methods, techniques, and practices; manual contents; tools; materials; equipment) is required to be and has been reviewed and formally approved by the FAA or appropriate Civil Aviation Authority (CAA). Approvals are granted only by letter, by a stamp of approval, by the issuance of operations specifications (OpSpecs), or by other official means. All data used to substantiate a major repair or major alteration, regardless of the source, must be approved before being used.
2.2.2.2 Acceptable Data.
2.2.2.2.1 Acceptable data means data acceptable to the FAA. The terms “acceptable to the Administrator” and “acceptable to the FAA” appear numerous times in the maintenance regulations. They refer to any item addressed in the regulation
(e.g., data; methods, techniques, and practices; manual contents; tools;
materials; equipment; etc.) that must meet regulatory standards. If the regulation requires only that an item must be “acceptable to,” it does not necessarily follow that the FAA requires the item to have specific FAA review and acceptance before it may be used. The person deciding if an item is “acceptable to” the agency must ensure the item addresses specific applicable section(s) of the regulations.
2.2.2.2.2 Items required by regulation to be “acceptable to” the FAA or to the Administrator (unless otherwise required by regulation to be approved) do not necessarily require FAA review and acceptance prior to a person using the
4 item. The person using an item that must be acceptable to the FAA should be able to demonstrate that the item meets all applicable regulatory requirements.
If, however, upon subsequent review of the item, the FAA believes the item is not acceptable, the agency has the burden of demonstrating its unacceptability in any related enforcement matter. In any event, if an ASI finds an item unacceptable to the FAA, the ASI must immediately inform the maintenance provider/certificate holder (CH), in writing, of the potential noncompliance and request compliance.
2.2.3 Previously Approved Data. This term refers to data that was approved for a specific purpose, such as a Supplemental Type Certificate (STC) or major alteration on an aircraft, powerplant, propeller, or appliance. All previously approved data submitted is applicable to the requested major repair or major alteration. It is essential that all differences, deviations, inclusions, and exclusions between the original use of the data and the current one be considered before the data can be approved for use. Figure 2-1, Possible Resources for Approved Data Relevant to Major Repairs or Major Alterations, lists typical sources by which you can obtain previously approved data. Not all this data may be readily available. It is the applicant’s responsibility to review all data that is available. Applicants should consider the following items when evaluating previously approved data:
2.2.3.1 Product Certification Basis. If the certification basis applicable to the product to be altered or repaired is different from the basis the previously approved data was developed for, the applicant should make a comparison of the two and address the differences in making a determination of applicability for use of the previously approved data.
2.2.3.2 Special Conditions. As per 14 CFR § 11.19, a special condition is a regulation that applies to a particular aircraft design. The FAA issues special conditions when the airworthiness regulations for an aircraft, aircraft engine, or propeller design do not contain adequate or appropriate safety standards, because of a novel or unusual design feature. If special conditions are required to show compliance, representative data must be specifically approved for the product or appliance intended for alteration or repair by the FAA under 14 CFR § 11.38. One example where a special condition may be needed would be the display of Synthetic Vision System (SVS) video on a Head-Up Display (HUD) to provide a level of safety equivalent to 14 CFR § 25.773.
Note: New and novel processes like Additive Manufacturing (AM)/3-D printing used to fabricate replacement parts may require much more substantiation than parts produced by traditional methods to determine equivalency to the original (design) or properly altered condition due to the different material properties, especially for a metal AM replacement part when compared to the original certification basis.
2.2.3.3 Equivalent Level of Safety (ELOS) Findings. If ELOS are used to show compliance, the FAA must find that an ELOS is achieved, which includes approving the underlying data for the specific product or appliance intended for alteration. Refer to 14 CFR § 21.21.
2.2.3.4 Exemptions. If data was developed and approved for a product design based on an exemption to an airworthiness standard, the applicant should consider the exemption impact and any deviation which may have been granted to the approved product or appliance. Such exemption or deviation may require independent approval by the FAA. An appropriately authorized Designated Engineering Representative (DER) or Organization Designation Authorization (ODA) may evaluate and recommend approval of an exemption as a part of the exemption request package.
2.2.3.5 Applicability. The applicant should review the data to determine applicability to intended use. If any data is not appropriate to the repair or alteration, it should not be referenced as supporting data.
6 Figure 2-1. Possible Resources for Approved Data Relevant to Major Repairs or Major Alterations Type Certificate Data Sheet (TCDS). Refer to FAA Order 8620.2, Applicability and Enforcement of Manufacturer’s Data, for guidance.
Repair data from AC 43.13-1, Acceptable Methods, Techniques, and Practices—Aircraft Inspection and Repair, as approved data for non-pressurized areas of civil aircraft (list the AC chapter, page, and paragraph in block 8 of FAA Form 337, Major Repair and Alteration (Airframe, Powerplant, Propeller, or Appliance)), when the applicant has determined that it is:
• Appropriate to the product that is to be repaired;
• Directly applicable to the repair being made; and
• Not contrary to the airframe, engine, propeller, or appliance manufacturers’ repair data or instructions.
Alteration data from AC 43.13-2, Acceptable Methods, Techniques, and Practices—Aircraft Alterations, as approved data for major alterations for non-pressurized areas of civil aircraft (list the AC chapter, page, and paragraph are listed in block 8 of FAA Form 337), when the user has determined that it is:
• Appropriate to the product to be altered;
• Directly applicable to the alteration being made; and
• Not contrary to the airframe, engine, propeller, product, or appliance manufacturers’ data.
Airworthiness Directives (AD).
Appliance manufacturer’s manuals or instructions, unless specifically not approved by the FAA, may be used as approved data for major repairs.
Data describing an article used in an FAA-approved alteration under a Parts Manufacturer Approval (PMA).
Designated Engineering Representative (DER)-approved data, including repair specifications, within limitations on the DER’s authorization.
Organization Designation Authorization (ODA)-approved data, within limitations in the ODA holder’s procedures manual.
FAA-approved portions of Structural Repair Manuals (SRM).
FAA-approved Service Bulletins (SB) and Service Letters (SL) or similar documents as documented in AC 20-77, Use of Manufacturers’ Maintenance Manuals.
Foreign bulletins, for use on U.S.-certificated foreign-designed aircraft, when approved by the foreign authority within the provisions of a bilateral agreement with the United States or as listed in TCDS notes.
Original aircraft manufacturer’s service and repair data in accordance with current regulations, for major repairs on elements of non-pressurized airplanes, 12,500 pounds or less maximum certificated takeoff weight provided the person intending to perform such repair determines that:
• Data is appropriate and applicable for the specific make, model, and type of product being repaired; and
• The repair does not deviate from the manufacturer’s methods, techniques, and practices.
United States Department of Commerce, Form ACA-337 dated prior to October 1, 1955, provided the data is appropriate, directly applicable, and not contrary to regulatory requirements.
Supplemental Type Certificate (STC) data may substantiate a major alteration on a different aircraft, provided such alteration is applicable to specifically listed make, model, and type appropriate to the certification basis and applicable amendments.
7 3 FIELD APPROVAL PROCESS AND DATA APPROVAL.
3.1 General Information. As discussed in paragraph 1.5 above, an applicant must use approved technical data to accomplish a major alteration or major repair on a product and approve the product for return to service. An applicant should perform three major steps when performing a major repair or major alteration: (1) conduct research, (2) evaluate the data, and (3) perform the repair or alteration.
Note: You should not start work until all data is approved. Inspectors may not be able to complete the approval as requested. If an applicant starts work before the approval is finalized, that work may not conform to the repair or alteration as approved.
3.2 Conduct Research.
3.2.1 Plan the Repair or Alteration. You should review the repair or alteration to be performed to determine whether certain aspects of the alteration or repair can be accomplished using acceptable data and/or whether other aspects of the alteration or repair require approved data. You must ensure that the performance of the alteration or repair meets the applicable airworthiness standards, and the product can be restored to its original or proper condition and is safe for operation. You need to determine the certification basis of the product, including all applicable amendments, to ascertain if the alteration or repair can be accomplished using the field approval process admissible as a minor change to the type design. You also need to determine if the intended alteration or repair is significant enough to warrant seeking an STC, as performing such an alteration or repair results in a major change to the type design. Typical data may include analysis, drawings, photographs, specifications, or test data as required. Refer to 14 CFR § 21.93 and the MRADA Job Aid associated with FAA Order 8300.16, Major Repair and Alteration Data Approval.
Note: Some aspects of the alteration or repair of a product may be performed using the field approval process. Whereas other aspects may be determined significant such that one or more certificated properties of the product are exceeded, thus requiring a new certification basis be established.
3.2.2 Determine the Repair or Alteration Classification. Determine if the repair/alteration is a minor change in type design (as defined in 14 CFR § 21.93) to the product’s type design;
and if so, is it a major or a minor repair/alteration. To determine if a repair/alteration is major or minor, refer to part 43 appendix A. Figure 3-2, Determination of Major or Minor Alteration or Repair, is a flowchart of the field approval evaluation process based on part 43 appendix A.
3.2.2.1 Minor Repair or Minor Alteration. If you are properly authorized, you may perform a minor repair/alteration using acceptable data, and without approved data. You may document the alteration or repair in the product’s logbook per 14 CFR § 43.9 indicating return to service.