21L.A.44 Compliance activities for a declaration of design compliance

VOLUNTARY INVOLVEMENT OF THE AGENCY PRIOR TO THE SUBMISSION OF THE DECLARATION The declarant may choose to involve EASA prior to submitting the declaration of design compliance. This would allow EASA to:

(a)check that the product is within the scope of Subpart C;

(b)provide guidance on the completeness of the compliance-demonstration plan and the selection of the means of compliance;

(c)provide guidance on the selection of the applicable detailed technical specifications and applicable noise requirements;

(d)provide guidance about and witnessing and participating to noise tests;

(e)avoid any issues or delays during the first-article inspection (after submission of the declaration of design compliance). The initiation of the project by the declarant by submitting a request to EASA may occur before starting the compliance activities or during those activities. The assignment of a dedicated project number would facilitate any subsequent communication with EASA. This will facilitate the provision of compliance documentation required by point 21L.A.43(c) which can be provided by the declarant to EASA at key stages in the compliance demonstration prior to submission of the declaration of design compliance. The declarant should also request access to EASA’s Part 21 Light database of declared noise levels referring to the given Agency project number in order to provide the required data under point 21L.A.43(b)(11) (see AMC1 21L.A.43(b)). In accordance with point 21L.B.61, the environmental protection requirements are defined in Regulation (EU) 2018/1139 to be those contained in Annex 16 to the Chicago Convention. As regards aircraft noise, noise testing is generally conducted making use of technical and equivalent procedures that are described in ICAO Doc 9501 ‘Environmental Technical Manual’, Volume I ‘Procedures for the Noise Certification of Aircraft’. The use of such procedures demands a deeper knowledge of the environmental protection requirements. In case of doubt and to minimise the risk of any re-test after the first-article inspection, the declarant is encouraged to contact EASA well before the noise flight test.

COMPLIANCE-DEMONSTRATION PLAN The compliance-demonstration plan is a document that allows the declarant to manage and control the evolving aircraft design, as well as the process of compliance demonstration that enables EASA to investigate the root cause(s) in the event of a safety issue being discovered. In particular, the following information should typically be expected: Identification of the relevant personnel that make decisions affecting airworthiness and environmental compatibility, and that will interface with EASA during the physical inspection (safety review) prior to the issuance of the flight conditions and during the first-article inspection. A project schedule, including major milestones. Subcontracting arrangements for design, environmental compatibility and/or production. Point 21L.A.43(c)(2) ‘Configurations covered by the declaration’ An overview of the following: architecture, functions, systems; dimensions, design weights, payloads, design speeds; engines and power/thrust rating; materials and technologies; cabin configuration aspects; options (e.g. weight variants, power/thrust rating variants, optional avionics equipment items, brake options, tyre options, floats, skids). Point 21L.A.43(c)(2) ‘Operating characteristics and limitations’ operating speed limitations; service ceiling, maximum airfield elevation; limit load factors; number of passengers, payload, range; weight and centre-of-gravity (CG) envelope and fuel loading; performance; environmental envelope; runway surface conditions; other items, if considered to be more appropriate, that address the specific aeronautical product. The declarant should provide detailed information about the means of compliance with the applicable requirements identified under point 21L.A.45. This should include the following: a compliance checklist addressing each requirement, the proposed means of compliance (see Appendix A to AMC1 21L.A.44(a) below for the relevant codes), and the related compliance document(s); identification of industry standards, methodology documents, handbooks and any other acceptable means of compliance, specified in the airworthiness data sheet, that have been followed in the demonstration of compliance; identification of methodologies and procedures laid down in Annex 16 to the Chicago Convention that have or will be followed in the demonstration of compliance with the applicable environmental protection requirements; when the compliance demonstration involves testing, a description of the ground-and flight-test article(s), test method(s), test location(s), test schedule, test house(s), test conditions (e.g. limit load, ultimate load), as well as of the intent/objective(s) of the testing; and when the compliance demonstration involves analyses/calculations, a description/ identification of the tools (e.g. name and version/release of the software programs) and methods used, the associated assumptions, limitations and/or conditions, as well as of the intended use and purpose. For every aspect related to airworthiness compliance mentioned above, the declarant should clearly identify whether the demonstration of compliance involves different means than those contained in the published AMC to the relevant CSs and any method (analysis or test) which is novel or unusual for the declarant. For every aspect related to compliance with the applicable environmental protection requirements mentioned above, the declarant should clearly identify whether the demonstration of compliance involves means that are described in ICAO Doc 9501 ‘Environmental Technical Manual’.

UPDATES TO THE COMPLIANCE-DEMONSTRATION PLAN The initial compliance-demonstration plan may not be fully complete, e.g. due to schedule constraints of the design, analysis and testing activities. Furthermore, even if the initial compliance-demonstration plan is complete, it may be necessary to amend it throughout the duration of the compliance-demonstration activities. In particular, updates to the following elements should be conducted by the declarant: any complementary information that was not included in the initial compliance-demonstration plan; any change to the intended use or kind of operation of the product; a change to the key characteristics of the product such as but not limited to any declared limits that are intended to be recorded in the airworthiness data sheet and noise data sheet; any change to the initial detailed technical specifications or environmental protection requirements, as applicable to the product; any change to the proposed means of compliance, including the related methodology; any changes to the schedule that impacts on the first-article inspection. The declarant should submit an updated and final version of the compliance-demonstration plan when submitting the declaration of design compliance to EASA (point 21L.A.43(c)(3)). If a declarant has chosen to involve EASA prior to the declaration (GM1 21L.A.44) and has already submitted a preliminary version of the compliance-demonstration plan to EASA, they should resubmit the updated and final version of it.

COMPLIANCE DOCUMENTATION

1.Compliance documentation 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 detailed technical specifications and environmental protection requirements has been demonstrated.

2.Each compliance document should normally contain: the reference of the detailed technical specifications or environmental protection requirements addressed by the document; substantiation data demonstrating compliance (except test or inspection programmes/ plans); a statement by the declarant declaring that the document provides the proof of compliance for which it has been created; and the declarant’s signature.

3.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 ‘Record-keeping’.

INSPECTIONS AND TESTS In accordance with point 21L.A.44(d), the declarant should address the conformity of the test specimen as well as of the test and measuring equipment. Conformity of the test specimen The recorded justification of the conformity of the test articles is intended to ensure that the manufactured test specimen adequately represents the declared applicable design data. Possible types of non-conformity may be the following: Non-conformity between the design of the test specimen and the originally intended design data at the time of the test. These are typically identified in the early stage of the test 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 existing 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 declarant does not need to make the distinction between the two types of non-conformity above as long as they are explicitly addressed and justified by cross reference to the test plan or other documents. However, testing for the demonstration of compliance with the environmental protection requirements should be conducted with the final design of the product. Compliance demonstration is typically an iterative process in which the design is under continuous evolution. If the aircraft design evolves after the time of the inspection or test, then the final aircraft design should be checked against the originally intended design (as it was at the time of the inspection or test), and the differences (if any) should be analysed to ensure that the inspection or test results are representative of the final configuration. However, such changes made to the aircraft design may lead to the invalidation of the inspection or test results and the need to repeat the inspection or test. It is recommended that the declarant should have a thorough configuration management process to track the evolving aircraft 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 test plans and supporting documentation. 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 declarant should confirm that the test and measuring equipment conform to its definition in the test plan, 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 can be done either in the recorded justification of the conformity of the test articles and equipment or by cross reference to other documents (test minutes of meetings, test notes, etc.). Use of the term ‘adequate’: 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 by masking any potential failure mode or behaviour). Changes that affect the validity of the recorded justification of the conformity of the test articles and equipment: if changes need to be introduced to the test specimen or to the test and measurement equipment after the justification has been recorded (and before the test is undertaken), then it must be updated. Development versus compliance-demonstration tests: sometimes, tests of specimens that conform to a preliminary design, but are not intended for demonstration of compliance (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.44(d) and (e). Any planned test event should be classified in advance as either a development test or a compliance-demonstration test. It is acceptable for a development test to finally form part of the compliance demonstration, and it may be declared afterwards to be a compliance-demonstration test as long as it meets the requirements of point 21L.A.44(d) and (e). For this reason, it is important to keep the configuration of such tests under control. If the test specimen used for a compliance-demonstration test has already undergone a series of previous tests that may affect or ultimately invalidate its validity due to potential non-conformity to point 21L.A.44(d) as required by point 21L.A.43(c)(5), this aspect should be considered when justifying the conformity, and specific analyses or inspections may be required to support such a statement. Because of the above aspects, declarants may wish to inform EASA if they intend to conduct a campaign of development tests that may eventually be used as demonstration of compliance tests to establish whether EASA would wish to witness the test.

INSPECTIONS AND TESTS PERFORMED BY THE AGENCY The declarant should inform EASA sufficiently in advance about the execution of significant inspections and tests that are used for compliance-demonstration purposes in order to permit EASA the opportunity to perform or witness these inspections or tests in advance of the first-article inspection required by point 21L.A.47(a). This would be advantageous for the declarant to avoid any issues or delays during the physical inspection (safety review) for the flight-conditions approval and during the first-article inspection. Additionally, the declarant may propose to EASA to perform or witness flight or other tests of particular aspects of the product during its development and before the type design is fully defined. However, before EASA performs or witnesses any flight test, the declarant should first perform these tests and should ensure that no features of the product preclude the safe conduct of the evaluation requested. A recorded justification of the conformity of the test articles and equipment as per point 21L.A.43(c)(5) is required for the above tests. The declarant should inform EASA of its intent to conduct demonstration-of-compliance testing for the environmental protection requirements for noise in order to provide EASA with the opportunity to witness and participate to the testing. This will ensure that there are no unforeseen issues with the registration of the declaration of design compliance after the first-article inspection.

FLIGHT TESTING TO ENSURE NO SAFETY ISSUES EXIST WHEN AN AIRCRAFT ENTERS INTO SERVICE The objective of the period of operation in the final configuration is to expose the aircraft to the variety of uses, including training, that are likely to occur when in routine service to provide an assurance that it performs its intended functions without safety issues and should continue to do so in service. The testing should cover typical routine operations and also some simulation of abnormal conditions. It may be possible to combine flight testing with the testing required to demonstrate compliance with the applicable detailed technical specifications and environmental protection requirements. A substantial proportion of the flying should be on a single aircraft. The flying should be carried out to a continuous schedule on an aircraft that is very close to the final type design, operated as though it were in service and should include a range of representative ambient operating conditions and airfields.

FLIGHT TESTING TO ENSURE NO ENVIRONMENTAL COMPATABILITY ISSUES EXIST WHEN AN AIRCRAFT ENTERS INTO SERVICE The objective of noise flight tests is to establish the environmental performance of the product that occurs during the in-service operation and to confirm that the aircraft is environmentally compatible in terms of aircraft noise.