21L.A.206 Demonstration of compliance

The description of the repair should include an explanation of the purpose of the repair, the pre-repair and post-repair configuration(s) of the product, schematics/pictures, and any other detailed features and boundaries of the repair (this may be supplemented by drawings or outlines of the design, if this helps to understand the repair), as well as the identification of the affected areas of the product that are functionally affected by the repair, and the identification of any changes to the approved manuals. The applicant should identify any reinvestigations that are necessary to demonstrate compliance. This is a list of affected items of the applicable certification basis for which a new demonstration is necessary, together with the means (e.g. calculation, test or analysis) by which it is proposed to demonstrate compliance. For a major repair, AMC1 21L.A.24(b)(4) should be used as applicable to the change for the development of the compliance-demonstration plan. Compliance documentation for the demonstration of compliance in point 21L.A.206(a) comprises one or more test or inspection programmes/plans, reports, drawings, design data, specifications, calculations, analyses, etc., and provides a record of the means by which compliance with the applicable type-certification basis and environmental protection requirements is demonstrated. Each compliance document should typically contain: the reference of the certification specifications, special conditions or environmental protection requirements addressed by the document; substantiation data demonstrating compliance (except test or inspection programmes/plans); a statement by the applicant declaring that the document provides the proof of compliance for which it has been created; and the appropriate authorised signature. Each compliance document should be unequivocally identified by its reference and issue date. The various issues of a document should be controlled and comply with point 21L.A.7. The level of detail of the compliance documentation that is referred to in point 21L.A.206(a) should be the same regardless of whether the repair is approved by EASA or under a design organisation approval (DOA) privilege, to allow the repair to be assessed in the frame of the DOA surveillance. The compliance-demonstration process always takes into account the specific configuration(s) in the type certificate (TC) to which the major repair under approval is applied. This (these) configuration(s) may be defined by product models/variants or by repairs to the type design. The demonstration of compliance covers this (these) applicable specific configuration(s). Consequently, the approval of the major repair excludes any other configurations, in particular those that already exist but are not considered in the compliance-demonstration process, as well as those that may be certified in the future. For major repairs approved by a design organisation approval (DOA) holder on the basis of its privilege as per point 21.A.263(c)(5) of Annex I (Part 21), the process described under AMC No 2 to 21.A.263(c)(5), (8) and (9) applies.

INSPECTIONS AND TESTS Proposed type design: this term defines the type design (or the portion of the type design) as it is determined at the time when the testing and inspections are performed. Verification document (also known as ‘statement of conformity’): before each testing and inspection, the verification document must confirm that the test specimen conforms with the proposed design, the test and measuring equipment is adequate for the test, and the sensors and measuring system are appropriately calibrated. Conformity of the test specimen: the documented verification is intended to ensure that the manufactured test specimen, even in the presence of non-conformities, adequately represents the proposed type design. Possible types of non-conformity may be the following: Non-conformity between the design of the test specimen and the proposed type design at the time of the test. These are typically identified in the early stage of the testing and inspections planning, and should be addressed as early as possible (e.g. in the test plan). There may be several reasons for such a non-conformity: to account for interfaces with the test equipment, to conservatively cover several or future design configurations, etc. Non-conformity between the manufactured test specimen and the design of the test specimen. Such a non-conformity may be the result of the manufacturing of the test specimen. While it is convenient to define any possible non-conformity as early as possible, the applicant does not need to make the distinction between the two types of non-conformity above as long as they are explicitly addressed, justified in the verification document or by cross reference to the test plan or other documents. However, testing for the demonstration of compliance with the applicable environmental protection requirements may be conducted in the final design of the product having incorporated the repair design. Type certification is typically an iterative process in which the design is under continuous evolution. If the type design evolves after the time of the testing and inspections, then the final type design should be checked against the proposed type design (as it was at the time of the testing and inspections), and the differences (if any) should be analysed to ensure that the testing and inspection results are representative of the final configuration. However, such changes made to the type design may lead to the invalidation of the testing and inspection results, and the need to repeat the testing and inspections. It is recommended that the design organisation should have a thorough configuration management process to track the evolving type design. Conformity of the test and measuring equipment: the configuration of the test and measuring equipment should be defined in the test plan and include the following: definition/design of the test equipment (relevant tools, mechanical parts, electronic components used to execute the test); and definition of the measuring equipment: type/model of sensors, together with their technical characteristics; position and orientation of exciters and sensors; and electronic measuring equipment (in some cases, this may also include the acquisition and post-processing of data). The configuration of the test and measuring equipment should be defined and controlled through certification test plans and supporting documentation, according to the design assurance system, if applicable. The test plan should also include the following elements: the test cases, methods, and procedures for test execution; the pass–fail criteria; and pre-, during- and post-test inspections. The verification document should confirm that the test and measuring equipment conforms to its purpose, and that the sensors and measuring system are appropriately calibrated. Any non-conformity should be assessed, and it should be justified that it will not compromise the test purpose and results. This may be done either in the verification document or by cross reference to other documents (test minutes of meetings, test notes, etc.). Use of the term ‘adequate’: the test specimen, as well as the test and measuring equipment, is considered ‘adequate’ as long as the test execution on the manufactured test specimen (including any non-conformity) and the use of the installed test set-up do not compromise the test purpose and results (for example, by providing better performance than the proposed type design, or masking any potential failure mode or behaviour). Changes that affect the validity of the verification document: if changes need to be introduced to the test specimen or to the test and measurement equipment after the verification is documented (and before the test is undertaken), then the verification document must be updated. The updated verification document must be made available to EASA before the test if EASA has informed the applicant that it will witness or carry out the tests or inspections. Development versus certification tests: sometimes, tests of specimens that conform to a preliminary design, but are not intended for certification (known as development tests), are performed as part of a risk control strategy and to develop knowledge of a subject. Problems and failures found during development are part of the process of increasing the understanding of the design, including its failure modes and the potential for optimisation. Such development tests do not need to meet the requirements of point 21L.A.206(c). Any planned test event should be classified in advance as either a development test or a certification test. Tests that support the compliance demonstration should be classified as certification tests. It is acceptable for a development test to finally form part of the compliance demonstration, and it may be declared afterwards to be a certification test as long as it meets the requirements of point 21L.A.206(c). For this reason, it is important to keep the configuration of such tests under control. If the test specimen used for a certification test has already undergone a series of previous tests that may affect or ultimately invalidate its acceptance as required by point 21L.A.206(c), this aspect should be considered when documenting the verification, and specific analyses or inspections may be required. Because of the above aspects, EASA advises applicants to inform EASA if they intend to conduct a campaign of development tests that may eventually be used as certification tests to establish whether EASA would wish to witness the tests.

REVIEW OF DATA AND INFORMATION RELATED TO THE DEMONSTRATION OF COMPLIANCE Availability of compliance data (see point 21L.A.206(e)): data and information required to be provided by the applicant should be made available to EASA in a reliable and efficient way as agreed with EASA.

TESTS AND INSPECTIONS The applicant should inform EASA sufficiently in advance about the execution of tests and inspections that: are used for compliance-demonstration purposes; and have been identified as being of particular interest to EASA during the review and approval of the compliance-demonstration plan in order to permit EASA the opportunity to witness or carry out these inspections or tests. The applicant may propose to EASA to witness or carry out flight or other tests of particular aspects of the product during its development and before the type design is fully defined. However, in case of flight tests, the applicant should perform the tests before EASA witnesses or performs them to ensure that no features of the product preclude the safe conduct of the evaluation requested. EASA may require any such tests to be repeated once the type design is fully defined to ensure that subsequent changes have not adversely affected the conclusions from any earlier evaluation. A verification document as per point 21L.A.206(c) is required for the above tests.

PHYSICAL INSPECTION OF THE FIRST ARTICLE The applicant should be prepared for any additional investigations as notified by EASA according to point 21L.B.203(c). Refer to AMC1 21L.A.25(e)(3) for an explanation of the activities performed under the first-article inspection.

DECLARATION OF COMPLIANCE All compliance-demonstration activities in accordance with the compliance-demonstration plan, including all the testing and inspections in accordance with point 21L.A.206(c) and all flight testing in accordance with point 21L.A.206(d), should be completed before the issuance of the final declaration of compliance. ‘No feature or characteristic’ that may make the product with the repair design unsafe in point 21L.A.206(f)(2) means the following: while every effort is made to address in the applicable certification basis all the risks to product safety that may be caused by the product, experience shows that safety-related events may occur with products in service, even though compliance with the certification basis is fully demonstrated. One of the reasons may be that some existing risks are not properly addressed in the certification basis. Therefore, the applicant should declare that it has not identified any such feature or characteristic. ‘No feature or characteristic’ that may make the product with the repair design environmentally incompatible (point 21L.A.206(f)(2): It is assumed that environmental compatibility is demonstrated when the product with the repair design complies with the applicable environmental protection requirements. Therefore, the applicant, when declaring that the product with the repair design complies with the applicable environmental protection requirements under point 21L.A.206(f)(1), should also declare that it has not identified any such feature or characteristic.