I think Ektorakos is correct. On page 23 the rules say a Flying Unit may not pick up units from an activated area. I don't see anything about dropping them off in an activated area.
Especially since you can normally move units from others areas into an already activated area if I've understood the rules right.
"It is important to note that a player may order units in a
way that would cause them to end up in an area containing
one of that player’s activation markers, as long as they do
not start out in an activated area." (p. 21)