GM No 1 to 21.A.239(a) Design assurance system    

CAA ORS9 Decision No. 1

1. Purpose

This GM outlines some basic principles and objectives of 21.A.239(a).

2. Definitions

2.1 The design assurance system is the organisational structure, responsibilities, procedures and resources to ensure the proper functioning of the design organisation.

2.2 The design assurance means all those planned and systematic actions necessary to provide adequate confidence that the organisation has the capability:

    — to design products or parts in accordance with the applicable CS and environmental protection requirements,

    — to demonstrate and verify the compliance with these CS and environmental protection requirements, and

    — to demonstrate to the CAA this compliance.

2.3 The ‘Type Investigation’ means the tasks of the organisation in support of the type- certificate, supplemental type-certificate or other design approval processes necessary to demonstrate and verify and to maintain compliance with the applicable CS and environmental protection requirements.

3. Design Assurance

The complete process, starting with the CS and environmental protection requirements and product specifications and culminating with the issuing of a type-certificate, is shown in the diagram on Figure 1. This identifies the relationship between the design, the Type Investigation and design assurance processes.

Effective design assurance demands a continuing evaluation of factors that affect the adequacy of the design for intended applications, in particular that the product, or part, complies with applicable CS and environmental protection requirements and will continue to comply after any change.

Two main aspects should therefore be considered:

— How the planned and systematic actions are defined and implemented, from the very beginning of design activities up to continued airworthiness activities;

— How these actions are regularly evaluated and corrective actions implemented as necessary.

Figure 1 - RELATIONSHIPS BETWEEN DESIGN, DESIGN ASSURANCE AND TYPE INVESTIGATION

3.1 Planned and Systematic Actions

For design organisations carrying out Type Investigation of products, the planned and systematic actions should cover the following tasks and procedures should be defined accordingly:

3.1.1 General

    a. To issue or, where applicable, supplement or amend the handbook in accordance with 21.A.243, in particular to indicate the initiation of design activities on a product.

    b. To assure that all instructions of the Handbook are adhered to.

    c. To conduct Type Investigation.

    d. To nominate staff as ‘compliance verification engineers’ responsible to approve compliance documents as defined in paragraph 3.1.3.

    e. To nominate personnel belonging to the Office of Airworthiness responsible as defined in paragraph 3.1.4.

    f. In the case of an applicant for a supplemental type-certificate, to obtain the agreement of the type-certificate holder for the proposed supplemental type-certificate to the extent defined in 21.A.115.

    g. To ensure full and complete liaison between the type design organisation and related organisations having responsibility for products manufactured to the type-certificate.

    h. To provide the assurance to the CAA that prototype models and test specimens adequately conform to the type design (see 21.A.33(b)(1)).

3.1.2 Chief Executive and Head of design organisation (or his or her Deputy)

    a. The Chief Executive should provide the necessary resources for the proper functioning of the design organisation.

    b. The Head of the design organisation, or an authorised representative, should sign a declaration of compliance (see 21.A.20(d) and 21.A.97(a)(3)) with the applicable CS and environmental protection requirements after verification of satisfactory completion of the Type Investigation. In accordance with 21.A.20(e) and 21.A.97(a)(4), his or her signature on the declaration of compliance confirms that the procedures as specified in the handbook have been followed (see also GM 21.A.265(b)).

    c. The functions of Chief Executive and Head of the design organisation may be performed by the same person.

3.1.3 Compliance Verification

    a. Approval by signing of all compliance documents, including test programmes and data, necessary for the verification of compliance with the applicable CS and environmental protection requirements as defined in the certification programme.

    b. Approval of the technical content (completeness, technical accuracy...), including any subsequent revisions, of the manuals approved by the CAA (Aircraft Flight Manual, the Airworthiness Limitations section of the

    Instructions for Continued Airworthiness and the Certification Maintenance Requirements (CMR) document, where applicable).

3.1.4 Office of Airworthiness

    a. Liaison between the design organisation and the CAA with respect to all aspects of the certification programme.

    b. Ensuring that a handbook is prepared and updated as required in 21.A.243.

    c. Co-operation with the CAA in developing procedures to be used for the type certification process.

    d. Issuing of guidelines for documenting compliance.

    e. Co-operation in issuing guidelines for the preparation of the manuals required by the applicable implementing rules, Service Bulletins, drawings, specifications, and standards.

    f. Ensuring procurement and distribution of applicable CS and environmental protection requirements and other specifications.

    g. Co-operating with the CAA in proposing the type-certification basis

    h. Interpretation of CS and environmental protection requirements and requesting decisions of the CAA in case of doubt.

    i. Advising of all departments of the design organisation in all questions regarding airworthiness, operational suitability, environmental protection approvals and certification.

    j. Preparation of the certification programme and co-ordination of all tasks related to Type Investigation in concurrence with the CAA.

    k. Regular reporting to the CAA about Type Investigation progress and announcement of scheduled tests in due time.

    l. Ensuring co-operation in preparing inspection and test programmes needed for demonstration of compliance.

    m. Establishing the compliance checklist and updating for changes.

    n. Checking that all compliance documents are prepared as necessary to demonstrate compliance with all CS and environmental protection requirements, as well as for completeness, and signing for release of the documents.

    o. Checking the required type design definition documents described in 21.A.31 and ensuring that they are provided to the CAA for approval when required.

    p. Preparation, if necessary, of a draft for a type-certificate data sheet and/or type-certificate data sheet modification.

    q. Providing verification to the head of the design organisation that all activities required for Type Investigation have been properly completed.

    r. Approving the classification of changes in accordance with 21.A.91 and granting the approval for minor changes in accordance with 21.A.95(b).

    s. Monitoring of significant events on other aeronautical products as far as relevant to determine their effect on airworthiness or operational suitability of products being designed by the design organisation.

    t. Ensuring co-operation in preparing Service Bulletins and the Structural Repair Manual, and subsequent revisions, with special attention being given to the manner in which the contents affect airworthiness and environmental protection and granting the approval on behalf of the CAA.

    u. Ensuring the initiation of activities as a response to a failure (accident/incident/in-service occurrence) evaluation and complaints from the operation and providing of information to the CAA in case of airworthiness or operational suitability impairment (continuing airworthiness and continued operational suitability).

    v. Advising the CAA with regard to the issue of airworthiness directives in general based on Service Bulletins.

    w. Ensuring that the manuals approved by the CAA, including any subsequent revisions (the Aircraft Flight Manual, MMEL, the Airworthiness Limitations section of the Instructions for Continued Airworthiness and the Certification Maintenance Requirements (CMR) document, where applicable) are checked to determine that they meet the respective requirements, and that they are provided to the CAA for approval.

3.1.5 Maintenance and Operating Instructions

(a) Ensuring the preparation and updating of all maintenance and operating instructions (including instructions for continued airworthiness and services bulletins) needed to maintain airworthiness (continuing airworthiness) in accordance with the relevant CSs. For that purpose, the applicant should:

    — establish the list of all documents it  is producing to  comply with   CS 2X.1581 and with the Appendix referred to in CS 2X.1529, CS-E 20/25 or CS-P 40;

    — establish a system to collect in-service experience to be used for the improvement of the instructions;

    — define procedures and organisation to produce and issue these documents, under the obligation of point 21.A.265(h); the procedures should cover:

      — preparation, including the format and language (available industrial standards can be referred to and used);

      — proofreading (checking for clarity, readability, typos, etc.);

      — checking of technical consistency with the corresponding approved change(s), repair(s) or approved data, including the effectivity, description, effects on airworthiness and environmental protection, especially when limitations are changed;

      — checking of feasibility in practical applications; and

      — responsibilities and authorised signatories.

(b) In accordance with 21.A.57, 21.A.61, 21.A.107, 21.A.119, 21.A.120A and 21.A.449, ensuring that these documents are provided to all known operators and all involved authorities.

3.1.6 Operational Suitability Data (OSD)

(a) Ensuring the preparation and updating of all OSD in accordance with relevant CSs. For that purpose, the applicant should:

— establish the list of all the documents it is producing to comply with CS-MMEL or CS-GEN-MMEL, CS-FCD, CS-CCD, CS-SIMD and CS-MCSD, as applicable;

— define its procedures and the organisation to produce and issue these documents under the obligation of point 21.A.265(h); these procedures should cover the aspects described in 3.1.5(a) above.

(b) In accordance with 21.A.57, 21.A.62, 21.A.108, 21.A.119 and 21.A.120B, ensuring that these documents are provided to all affected operators and training organisations and all involved authorities.

3.2 Continued effectiveness of the design assurance system. The organisation should establish the means by which the continuing evaluation (system monitoring) of the design assurance system will be performed in order to ensure that it remains effective.