The Lisbon Treaty makes a distinction between two sets of Commission implementing rules – implementing acts (IA) and delegated acts (DA). Delegated and implementing acts are subject to different procedures for their adoption. More information on these two types of act can be found in the European Commission’s website (https://ec.europa.eu/info/law/law-making-process/adopting-eu-law/implementing-and-delegated-acts_en#documents).
No delegated acts are yet adopted under the EASA Basic Regulation, since these two different types of implementing rules were only introduced by the latest Basic Regulation (2018/1139). However, the Commission has adopted delegated acts in other domains, so it that respect, it is nothing new.
It is also important to highlight that this difference in procedure for the adoption of DA and IA at Commission level does not affect the EASA rulemaking procedure, which will remain the same regardless of the type of act that will in the end be adopted.