Part 21 Design Organisation
According to the EU regulations, aircraft design organisation has to acquire Design Organisation Approval (DOA). Certification of design organisations and issuance of DOA shall be carried out by European Aviation Safety Agency.
DOA issuance is regulated by:
Commission Regulation (EU) No 748/2012 of 3 August 2012 laying down implementing rules for airworthiness and environmental certification of aircraft and related products, parts and appliances, as well as for the certification of design and production organisations (SL L 224 21.8.2012)