AC 21-23B

Advisory circular · Airworthiness Certification of Civil Aircraft, Engine, Propellers, and Related Products Imported to the United States

Approved
November 17, 2004
Last reviewed
January 19, 2017
Cancels
AC21-23A
Family
AC 21-23 · 3 versions
Revision
B
14 CFR parts
21

Guidance, not mandatory unless a rule or AD requires it. DRS record last changed October 23, 2026.

Show pages 32–43

installation on U.S.-registered aircraft in accordance with the applicable FAA-approved design.

(2) 14 CFR 21.502(a) also provides for the airworthiness acceptance of appliances and their parts manufactured in a foreign country with which the U.S. has an agreement for the acceptance of those appliances and their parts. Neither an FAA letter of TSO design approval nor a Certificate of Airworthiness for Export issued by the CAA of the country of manufacture conveys installation approval. Installation approval for a TSO product or part should be obtained, in a manner acceptable to the FAA, at the time of installation on a U.S. registered product.

(3) A key phrase in 14 CFR 21.502(a) is that the product must be “manufactured in a foreign country with which the U.S. has an agreement for the acceptance of those materials, parts, or appliances for export and import.” Generally, the U.S. does not have bilateral agreements that address all parts. Excluding the agreements between the U.S. and Canada and the U.S. and Germany, the present bilateral agreements between the U.S. and other countries only permit the import of materials, parts, components, subassemblies, etc., in support of the bilateral partner country’s exported Class I products (e.g., aircraft, aircraft engine or propeller) or TSO appliances. (See appendix 4). Imported materials, parts and appliances must be directly traceable back to an FAA-approved design.

(4) The BASA IPA between the FAA and Transport Canada (TCCA) recognizes the equivalence of U.S. Parts Manufacturer Approvals and Canadian replacement parts approvals (via STC for replacement parts or repair design certifications with a manufacturing approval). These parts, when accompanied by TCCA Authorized Release Certificates in accordance with the BASA IPA, are eligible for import and installation on a U.S. product.

c. Airworthiness Acceptance – Used Engines, Propellers, Materials, Parts, and Appliances. Bilateral agreements do not include the reciprocal acceptance of used engines, propellers, materials, parts, or appliances. Any U.S. acceptance of used engines, propellers, materials, parts or appliances is dependent upon satisfying applicable FAA airworthiness and maintenance requirements. In addition, for imported items, acceptance of these imported items, when new, must have been within the scope of a bilateral agreement.

d. Identification and Marking

(1) Aircraft, aircraft engines, and propellers must be identified in a manner specified in 14 CFR 45.11.

(2) Critical components of a product must be identified with a part number (or equivalent) and serial number (or equivalent), as required in 14 CFR 45.14.

(3) Appliances and articles of a design approved by an FAA letter of TSO design approval must be marked in accordance with the requirements specified in 14 CFR part 21, subpart O, and any additional marking requirements specified in the 36

particular TSO. Approved deviations shall be marked by the holder of the TSO design approval on the TSO appliance or noted in attached limitations.

(4) Parts to be used as replacement or modification parts should be identified by a part number, serial number if applicable, and the manufacturer's name or trademark. In addition, information concerning the model designation and the type certificated product for which the part is eligible for installation should be furnished. If the bilateral agreement permits production of parts to a U.S. STC design, those parts should be marked with the U.S. STC number, as size permits. If size does not permit, information should accompany each part that identifies the applicable STC. This information can be included on the appropriate airworthiness release document. AC 20- 62 -- Eligibility, Quality, and Identification of Aeronautical Replacement Parts – prescribes the eligibility, quality, and traceability of aeronautical replacement parts.

3-4. REBUILT PRODUCTS. Rebuilt products are not eligible for import to the U.S.

14 CFR 43.3(j) limits rebuilding to manufacturers that hold FAA production approvals to manufacture aircraft, aircraft engines, propellers, or appliances. As a matter of policy, the FAA does not issue approvals to manufacture these products outside the U.S.

3-5. SPECIAL MAINTENANCE RECORDS CONSIDERATION. The information provided in paragraphs 3-1 through 3-3 above apply to aircraft or related products intended for operation under the General Operating and Flight Rules of 14 CFR part 91.

U.S. operators, such as those certificated by the FAA for operation under 14 CFR parts 121, 125, and 135, are required to acquire, retain, and record sufficient maintenance information on aircraft and related products. This enables an operator to integrate the aircraft or related product into its own FAA-approved maintenance program. This can prove difficult for U.S. operators unless the records are complete and are either written in English or can be translated into English. Operators and potential U.S. operators of imported aircraft, including used U.S.-manufactured aircraft, should realize that an FAA airworthiness certificate does not automatically render an aircraft or product eligible for operation. FAA operating requirements may specify the need for additional maintenance records, inspections and tests, and the installation of instruments and equipment not specified in the basic airworthiness certification requirements.

3-6.-3-9. (RESERVED)

37 (and 38)

CHAPTER 4. PRODUCTION APPROVALS

4-1. GENERAL. FAA approval of a U.S. manufacturer's production quality control system facilitates FAA airworthiness certification, approval, or acceptance of products manufactured at that facility. These production quality control system approvals support the manufacturer's obligation to ensure that the products delivered from the facility conform to the approved design and are in a condition for safe operation. For products manufactured outside the U.S., the bilateral agreement is based on FAA confidence in the production quality control system of a bilateral partner. The export certification of airworthiness from the CAA of a country with which the U.S. has a bilateral agreement serves the same purpose as the FAA’s certification. Therefore, the FAA does not normally issue production approvals outside the U.S.

4-2. MANUFACTURING LIMITATIONS RELATED TO A BILATERAL AGREEMENT

a. Any U.S. manufacturer may propose to use the services of a foreign supplier or subcontractor to furnish components (materials, parts, or subassemblies) for use on products, which are, or may be, certified or approved (i.e., production or prototype). Such proposals will be reviewed by the FAA in accordance with 14 CFR 21.43, 21.137, 21.303(g), and 21.601(c).

b. A U.S. manufacturer may propose to use suppliers and subcontractors in any country for the manufacture of components without benefit of bilateral agreements, provided the U.S. manufacturer holds an FAA production approval including an FAA approved quality control or fabrication inspection system to adequately verify that components produced in those countries conform to the manufacturer’s approved design data. The FAA will not, however, permit direct shipment from a supplier or subcontractor located in a country that does not have a bilateral agreement with the U.S., unless the Administrator finds no undue burden on the U.S. in administering the applicable requirements of 14 CFR part 21. These procedures are explained more fully in AC 21-20, Supplier Surveillance Procedures.

c. A U.S. manufacturer may use a supplier located in a country with which the U.S. does not have a bilateral agreement only if the authorities of that country would not inhibit, in any manner, an evaluation of the supplier by the FAA and that evaluation does not create an undue burden for the FAA to administer. Assurance of access should be provided to the U.S. manufacturer by both the supplier and the government of the country in which the supplier is located. This assurance of access should be made available to the FAA. If access is at any time obstructed or denied, the U.S. manufacturer will be instructed by the FAA to cease using the supplier.

4-3. EXTENSIONS OF FAA PRODUCTION APPROVALS TO COUNTRIES OUTSIDE THE U.S.

a. The FAA may extend a Production Certificate to include a facility located outside the U.S. when: 1) production takes place in a country with which the U.S. has a bilateral agreement; and 2) the CAA of that country is willing to conduct the necessary 39

surveillance at facilities located in their country on behalf of the FAA. Guidance related to extensions is contained in AC 21-24, Extending a Production Certificate to a Facility, Located in a Bilateral Airworthiness Agreement Country, and in the applicable country’s BASA IPA.

b. When a production approval has been granted or extended by the FAA or CAA of a country of manufacture, the approving authority will be fully responsible for the surveillance and oversight of the manufacturing facilities, wherever located, including a "third country."

4-4. PRODUCTION UNDER LICENSE TO A U.S. APPROVAL HOLDER

a. The FAA or CAA of country of manufacture may grant a production approval in their respective countries based on design data obtained through licensing agreement with a TC holder in the other country. In this case the authority granting that production approval would ensure that:

(1) Adequate manufacturing processes and established quality control procedures exist to ensure that each product conforms to its approved licensed design data; and

(2) A process exists that specifies who has design authority and ensures that the design approval holder and its CAA approves all design changes made by the licensee.

b. Production approvals based on licensing agreements will be addressed on a case by case basis in accordance with a BASA IPA.

4-5. CAA SURVEILLANCE ASSISTANCE ON BEHALF OF THE FAA

a. If a U.S. manufacturer uses a supplier in a country with which the U.S.

has a bilateral agreement, the FAA may utilize the country’s CAA for surveillance activities and/or inspection as a means of determining that the product or service provided by the supplier meets the type design, and that the supplier is adhering to the U.S. manufacturer’s quality requirements. When the CAA in a country with which the U.S. has a bilateral agreement is requested by the FAA to conduct surveillance activities or conformity inspection(s) at a supplier's facility, the U.S. manufacturer will incur all charges that the CAA may impose to accomplish the request(s).

b. FAA production approval and supplier surveillance programs are described in FAA Order 8120.2, Production Approval and Certificate Management Procedures, AC 21-20, Supplier Surveillance Procedures, and FAA Order 8100.7, Aircraft Certification Systems Evaluation Program.

CHAPTER 5. CONTINUED AIRWORTHINESS

5-1. GENERAL

a. Bilateral agreements provide for close cooperation between countries in the resolution of safety issues that can arise from in-service operation of any product exported/imported and approved or accepted under the terms of the agreement. When a safety concern arises, the FAA cooperates with its partner to determine the appropriate corrective action to be taken by operators or owners of affected U.S.-registered aircraft. The FAA expects exporting CAA’s to keep it informed of corrective actions that they believe are required for the safety of U.S.-registered aircraft.

b. The FAA also works closely with its counterpart authority to approve changes to type designs. These changes may consist of design improvements, changes necessary for continued airworthiness, repair information, or customer options.

5-2. CONTINUED AIRWORTHINESS DOCUMENTS

a. Continued Airworthiness Service documents (e.g., service bulletins, structural repair manuals, supplemental structural inspection documents), approved by the airworthiness authority of the country where an affected product is manufactured, are considered to be FAA-approved unless otherwise noted in a specific bilateral agreement. However, service bulletins or other similar instructions classified as "mandatory" by the exporting CAA are not mandatory under 14 CFR unless required by an FAA AD.

b. Owners or operators of affected U.S.-registered aircraft or engines, propellers, appliances and parts (i.e., products) are not required under U.S. law to comply with service documents or directives issued by the airworthiness authorities of other countries unless an FAA AD is issued under 14 CFR part 39. FAA AD’s are published in the Federal Register. AD’s issued during the current calendar year are available on the Internet at http://av-info.faa.gov. Information for ordering ADs can also be obtained from the FAA’s Delegation & Airworthiness Programs Branch, AIR-140, P.O. Box 26460, Oklahoma City, Oklahoma, 73125.

c. The FAA is committed to sharing safety critical information as soon as possible with its bilateral partners. FAA maintains an automated data-base of all service difficulty reports received from the aviation community, including reports on imported products. This data is available on the Internet at http://av-info.faa.gov.

d. The FAA has filed an official difference with ICAO over the ICAO requirement for states to require that a system exists to transmit continuing airworthiness information to type design organizations. (See ICAO Annex 8, Part II, paragraph 4.2.5.) Instead, the FAA shares significant information with the certificating 41

authority. In addition the FAA makes its Service Difficulty Reporting (SDR) system database available on the Internet at the address listed in c. above.

5-3. NOTIFICATION OF UNSAFE CONDITION AND MANDATORY CONTINUING

AIRWORTHINESS ACTIONS

a. When an exporting CAA issues a mandatory continuing airworthiness action for an unsafe condition that exists in a product, the FAA evaluates the information provided by the exporting CAA about the unsafe condition to determine whether the condition is likely to exist or develop on another product of the same type design. The exporting CAA should provide the FAA the following information:

(1) Make, model, and serial numbers of the affected product;

(2) Description of the unsafe condition, reasons for the mandatory action, and its impact on the affected aircraft and its continued operation;

(3) Description of the cause of the unsafe condition (e.g., stress, corrosion, fatigue, design problem, quality control, suspected unapproved part);

(4) The means by which the unsafe condition was detected and, if resulting from in-service experience, the number of occurrences;

(5) Corrective actions and corresponding compliance times, with a list of the relevant manufacturer’s service information, including reference number, revision number and date;

(6) The number of aircraft operating in the U.S. (important to the FAA) vs.

the number of aircraft worldwide needing corrective action;

(7) A statement on the availability of parts; and

(8) An estimate of the number of labor hours and the cost of parts required for the corrective actions.

b. When an exporting CAA does not issue a mandatory continuing airworthiness action, but the FAA determines that one may be necessary, the exporting CAA should facilitate the manufacturer’s providing sufficient information, including service bulletins, to the FAA in a timely manner for use in evaluating the need for an AD.

c. Continued airworthiness information should be sent to the FAA’s Delegation & Airworthiness Programs Branch, AIR-140, P.O. Box 26460, Oklahoma City, Oklahoma, 73125.

5-4. DESIGN CHANGES.

a. Following the type certification of an aircraft, it frequently becomes necessary to revise data on the aircraft type design. Major changes to a type design not great enough to require an application for a new TC, sought by the TC holder, may be issued as amendments to the type certificate issued under 14 CFR 21.29, or otherwise approved by the FAA. A certification procedure similar to that described in Chapter 2 is conducted and adjusted for the magnitude and complexity of the design change. The FAA retains the right to determine whether the proposed change is substantial enough to require a new type certificate for the changed type design.

b. Major changes to a type certificated design (for aircraft, aircraft engines, and propellers) which do not require an application for a new type certificate may also be approved through the issuance of a U.S. STC. Minor changes made by the type certificate holder are considered approved by the FAA upon approval by the exporting CAA under its normal procedures.

c. Each voluntary change in the type design of an aircraft or engine that may increase fuel venting or exhaust emissions is an “emissions change” as specified in 14 CFR 21.93, and requires further demonstration of compliance with 14 CFR part 34.

Similarly, each voluntary change in the type design of an aircraft that may increase the noise levels of that aircraft is an “acoustical change,” requiring demonstration of compliance with 14 CFR part 36.

d. Changes described in service bulletins, structural repair manuals, supplemental inspection documents, etc., with a CAA approval statement are accepted by the FAA and can be considered to be FAA-approved only under bilateral agreements. Such approval pertains to the aircraft type design only, and further FAA evaluation of installation or operational implications may be necessary.

5-5. APPROVAL OF DESIGN DATA USED TO SUPPORT REPAIRS. Repair data used to support minor repairs must be acceptable to the Administrator. Repair data used to support major repairs must be approved by the Administrator or conform to the provisions of a bilateral agreement. The FAA may accept design data to support repairs when approved by the CAA under the conditions included in a BASA IPA.

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Appendix 1

APPENDIX 1. AIRCRAFT CERTIFICATION SERVICE ORGANIZATIONAL CHART

Director, AIR-1 Deputy Director, AIR-2 International Policy Office, AIR-40 Special Assistants, AIR-3 & AIR-4 Engine & Propeller Directorate ANE-100 Rotorcraft Directorate ASW-100 Planning & Program Management Division AIR-500 Engineering Division AIR-100 Production & Airworthiness Division AIR-200 Small Airplane Directorate ACE-100 Transport Airplane Directorate ANM-100 SingaporeBrussels = Located outside of Washington Headquarters 1 (and 2)

Appendix 2

APPENDIX 2. ACCOUNTABLE FAA DIRECTORATES

Engine and Propeller Directorate ANE-100 Regulatory and policy responsibility for all aircraft engines, propellers, and auxiliary power units.

12 New England Executive Park Burlington, Massachusetts 01803 Telephone: (781) 238-7100 Fax: (781) 238-7199

Bilateral Countries Assigned to ANE: Belgium, Canada, Japan, Singapore, Taiwan, and United Kingdom

Rotorcraft Directorate ASW-100 Regulatory and policy responsibility for normal and transport category rotorcraft.

2601 Meacham Blvd.

Fort Worth, TX 76137-4298 Telephone: (817) 222-5100 Fax: (817) 222-5959

Bilateral Countries Assigned to ASW: Indonesia, Italy, and South Africa

Small Airplane Directorate ACE-100 Regulatory and policy responsibility for:

1. Normal, utility, and acrobatic ca tegory airplanes weighing less than 12,500 pounds and having passenger configurations of 9 seats or fewer;

2. Commuter category airplanes weighing 19,000 pounds or less, with passenger configurations of 19 seats or fewer; and

3. Primary category aircraft, gliders, airships, and hot air balloons.

DOT Building 901 Locust, Room 301 Kansas City, MO 64106-2641 Telephone: (816) 329-4100 Fax: (816) 329-4106

Bilateral Countries Assigned to ACE: Austria, Argentina, Australia, Czech Republic, Germany, Malaysia, New Zealand, Poland, Romania, Russia, and Switzerland

Appendix 2

APPENDIX 2. ACCOUNTABLE FAA DIRECTORATES (Continued)

Transport Airplane Directorate ANM-100 Regulatory and policy responsibility for all transport category airplanes.

1601 Lind Avenue, SW Renton, WA 98055-4056 Telephone: (425) 227-2104 Fax: (425) 227-1100

Bilateral Countries Assigned to ANM: Brazil, China, Denmark, Finland, France, Israel, Netherlands, Norway, Spain, and Sweden

NOTE: For countries not listed above, contact the International Policy Office, AIR-40.

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Appendix 3

APPENDIX 3. BILATERAL AGREEMENTS RELATED TO AIRWORTHINESS (AS OF SEPTEMBER 30, 2004)

COUNTRY AGREEMENT TYPE APPLICATION/SCOPE OF U.S. ACCEPTANCE 1 Argentina • BAA

• Schedule of Implementation Procedures All aeronautical products, including components 2 Australia • BAA All aeronautical products and certain components 3 Austria • BAA All aeronautical products 4 Belgium • BAA All aeronautical products and certain components 5 Brazil • BAA (replaced)

• Brazil Bilateral Aviation Safety Agreement – Executive Agreement

• Implementation Procedures for Airworthiness All aeronautical products and certain components.

Also recognizes Supplemental Type Certificate and maintenance.

6 Canada • BASA Executive Agreement

• Implementation Procedures for Airworthiness All aeronautical products, including components 7 China • BAA Schedule of Implementation Procedures Applies to fixed-wing aircraft not exceeding 12,500 lbs., commuter category airplanes up to 19 passengers with a maximum certificated takeoff weight of 19,000 lbs. or less, and TSO appliances 8 Czech Republic • BAA

• Operating Procedures All aeronautical products 9 Denmark • BAA All aeronautical products and certain components 10 Finland • BAA Applies to gliders and aircraft appliances 11 France • BAA (replaced)

• Bilateral Aviation Safety Agreement Executive Agreement

• Implementation Procedures for Airworthiness Applies to all aeronautical products and certain components. Also recognizes STC’s on French products.

Appendix 3 APPENDIX 3. BILATERAL AGREEMENTS RELATED TO AIRWORTHINESS (Continued) (AS OF SEPTEMBER 30, 2004) 2

COUNTRY AGREEMENT TYPE APPLICATION/SCOPE OF U.S. ACCEPTANCE 12 Germany • BAA (replaced)

• BASA Executive Agreement Implementation Procedures for Airworthiness (Revision 1) Applies to all aeronautical products and certain components. Also recognizes Supplemental Type Certificates on U.S.

and German products.

13 Indonesia • BAA

• Schedule of Implementation Procedures Applies to production oversight in Indonesia under licensing agreements with U.S.

manufacturers 14 Israel • BAA (replaced)

• Bilateral Aviation Safety Agreement—Executive Agreement

• Implementation Procedures for Airworthiness (Revision 1) All aeronautical products, appliances, and components. Also recognizes STC’s on U.S.

and Israeli airplanes.

15 Italy • BAA (replaced)

• Bilateral Aviation Safety Agreement-Executive Agreement

• Implementation Procedures for Airworthiness All aeronautical products and certain components.

Also recognizes STC’s on Italian products.

16 Japan • BAA All aeronautical products and certain components 17 Malaysia • Bilateral Aviation Safety Agreement-Executive Agreement

• Implementation Procedures for Airworthiness (Revision 1) Technical Standard Order appliances and small airplanes up to 9 passengers with a maximum certificated takeoff weight of 12,500 lbs.

18 Netherlands • BAA (replaced)

• Bilateral Aviation Safety Agreement- Executive Agreement

• Implementation Procedures for Airworthiness Aircraft products and certain components. Also recognizes STC’s on Dutch products.