High demand of flights on elementary air traffic control sectors results in high delays, extra-fuel burn and CO2 emissions, and may also lead to safety issues due to the destabilization of the aviation network. This paper presents a new control strategy approach to keep control of the current flight demand in European busiest sectors (Reims, Paris and Marseille sectors). Flow management positions in Area Control Centers suggest to airline operations centers delay-free routes for the most capacity impeding flights within the French airspace. Instead of spreading flight demand over time, this innovative approach aims at spreading the demand in space, relying on local expertise and enhanced collaboration. The trials conducted from July to September 2015 proved to be beneficial for airlines operations with more than 12,000 minutes of delay saved compared to summer 2014 while traffic increased by more than 6% from 9h to 13h UTC. Following Airport-Collaborative Decision Making, the Collaborative Advanced Planning process paves the way for the En-Route Collaborative Decision Making concept.