Eine kleine Quellensammlung mit unterschiedlichen Diskussionssträngen zum selben Thema.

Relevant ist natürlich eigentlich nur die gesetzliche Vorgabe aus Basic Regulation in Verbindung mit EASA FCL. Unklar ist manchen die Auslegung.

The Basic Regulation (216/2008):
1. Aircraft, including any installed product, part and appliance, which are:
...
(c) registered in a third country and used by an operator for which any Member State ensures oversight of operations or used into, within or out of the Community by an operator established or residing in the Community;
...
shall comply with this Regulation.
2. Personnel involved in the operations of aircraft referred to in paragraph 1(b), (c) or (d) shall comply with this Regulation.

https://www.peter2000.co.uk/aviation/easa/jan-brill-article-20120408.pdf

https://www.peter2000.co.uk/aviation/easa/index.html

https://www.peter2000.co.uk/aviation/easa/easa-fra-2010.pdf