Tons of people are shit-scared of flying and are visibly anxious. Tons of people drug themselves with benzos before flying.
But regardless of those two points, when the victim is at the point where they would be in an airplane with their pimp, controller, whatever you want to call them, they’re likely going to be well under their thumb, or happy thinking about that wonderful American business opportunity as a secretary or whatever they think is on the other side of the flight.
Sometimes it doesn’t play out like that, but often it does.
Many times they don’t use commercial air flights like you suggest, they drive. That’s why there are apps that allow you to take a 360° view of your hotel/motel/hostel so they can match them up with known sexual abuse videos.