Out of LIG the route takes you over Poitiers then a right turn to Nantes, another right turn towards a waypoint just east of Cherbourg.
Over the Channel to Portsmouth, around the west of London, almost over the top of Heathrow to Hemel Hempstead then north up the M1 to Leicester.
Sometimes if the French military aren't too busy we get a more direct routing, missing out Poitiers and heading towards Nantes before getting another direct towards Cherbourg.