text: I think this is now both the Bell Training Academy and the Floyd Carlson Airfield. Opened late 2018 not on any recent aerial imagery but
  
  see: https://www.reddit.com/r/whatisthisthing/comments/ba2dir/saw_this_after_taking_off_from_dallas_fort_worth/ 
  
  and 
  
  http://www.bellflight.com/support-and-service/training/facilities/united-states