November 28, 2023


Sofema Aviation Service (SAS) considers the regulatory requirements as a part of the EASA Safety Management System and the Design Management System.

21.A.239 Design management system within a Part 21 Subpart J Design Organisation

  • The design organisation shall establish, implement and maintain a design management system that includes a safety management element and a design assurance element with clearly defined accountability and lines of responsibility throughout the organisation.
  • The design management system shall:

o   Correspond to the size of the organisation and to the nature and complexity of its activities, taking into account the hazards and associated risks inherent in those activities;

o   Be established, implemented and maintained under the accountability of a single manager appointed pursuant to point 21.A.245(a).

  • As part of the safety management element of the design management system, the design organisation shall:

o   Establish, implement and maintain a safety policy and the corresponding related safety objectives;

o   Appoint key safety personnel in accordance with point 21.A.245(b);

o   Establish, implement and maintain a safety risk management process that includes the identification of aviation safety hazards entailed by its activities, their evaluation and the management of the associated risks, including taking actions to mitigate the risks and verify their effectiveness;

o   Establish, implement and maintain a safety assurance process that includes:

  • The measurement and monitoring of the organisation‚Äôs safety performance;
  • The management of changes in accordance with points 21.A.243(c) and 21.A.247;
  • The principles for the continuous improvement of the safety management element;

o  Promote safety in the organisation through:

  • Training and education;
  • Communication;
  • Establish an occurrence reporting system in accordance with point 21.A.3A in order to contribute to continuous improvement of safety.
  • As part of the design assurance element of the design management system, the¬† design organisation shall:

o  Establish, implement and maintain a system for the control and supervision of the design, and of design changes and repairs, of products, parts and appliances covered by the terms of approval; that system shall:

  • Include an airworthiness function responsible for ensuring that the design of of products, parts and appliances, or the design changes and repairs,
  • comply with the applicable type-certification basis, the applicable operational suitability data certification basis and the environmental protection requirements;
  • Ensure that the design organisation properly discharges its responsibilities in accordance with this Annex and with the terms of approval issued under point 21.A.251;
  • Establish, implement and maintain an independent verification function on the basis of which the design organisation demonstrates compliance with the applicable airworthiness, operational suitability data and environmental protection requirements;
  • Specify the manner in which the design management system accounts for the acceptability of the parts or appliances that are designed or the tasks that are performed by its partners or subcontractors according to the methods which are the subject of written procedures.
  • The design organisation shall establish, as part of the design management system, an independent monitoring function to verify compliance of the organisation with the relevant requirements of this Annex as well as the compliance with and adequacy of the design management system.
  • Monitoring shall include feedback to the person or the group of persons referred to in point 21.A.245(b) and to the manager referred to in point 21. A.245(a) to ensure, where necessary, the implementation of corrective action.

Next Steps

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