Is Norwegian maintaining its ability to come back
No matter if they have their planes on pay by the hour, should Norwegian circulate both planes and pilots to keep them in certification and at peek performance. Neither Norway nor Europe is a desert where you can just park you planes and think they are in the same condition after a few months. And pilots need a certain amount of take offs and landings to keep their certificates current. Rotate at least regularly all instructors on both types of aircraft. It isn't a coincidence that Ryanair is starting up again before 4 months has passed, and that they have been doing regular touch and go's at their bases.