Article 4 of Regulation (EU) No 748/2012 - Continued validity of supplemental type-certificates
With regard to supplemental type-certificates issued by a Member State under JAA procedures or applicable national procedures and with regard to changes to products proposed by persons other than the type-certificate holder of the product, which were approved by a Member State under applicable national procedures, if the supplemental type-certificate, or change, was valid on 28 September 2003, the supplemental type-certificate, or change shall be deemed to have been issued under this Regulation.
These STCs/changes being deemed to have been issued under this Regulation were EASA valid certificates at the date of 31.12.2020 (irrespective of their origins and like any other certificate issued in accordance with Reg. 748/2012) and are therefore covered by Article 15 of ANNEX AVSAF-1.
As per Article 3 and 6 of Regulation (EU) No 748/2012 - Continued validity of type-certificates and related certificates of airworthiness and parts and appliances certificates, the same applies in analogy to Type Certificates and European Technical Standard Orders.