I had many times to define the term “operator” under private or commercial flights context. First for cases I defended as a lawyer. Now for this foreign operators project.
“Operator” is not defined in EU law, neither in 178/2011 or Regl. 145 (cf. this page), nor in 216/2008.
That means that the general definition applies as “any legal or natural person, operating or proposing to operate one or more aircraft”, more precisely “the person or company organizing a flight under its operational control”.
The operator is in charge to prepare the flight (NOTAM, MET reports, FPL), to get the necessary PPR/slots and to pay the expenditures (landing taxes, handling, fuel, etc.). It can be also responsible to monitor the aircraft’s maintenance, insurances and airworthiness statement.
Things have to be clear: The “operator” does not have necessarily – including in private flights – to be the same person as the pilot-in-command !
While this is usually the case (OPR/PVT) in non-commercial operations, nothing precludes a different situation : an “N” aircraft operated by a Moroccan company, for a private flight, with a European natural person as pilot-in-command with a FAA license.
In fact, EU law 216/2008 distinguishes expressly the definition of “pilot” and “operator”.
The important point is that the pilot will consider his company as the only organizer of their flights.
If this is the case, his company will be considered as a valid foreign operator.