“Civil-military coordination and collaborative decision-making are key if we are to sustainably optimise our use of airspace.”


While European military discussions are currently dominated by the situation in Ukraine, there is no denying that sustainability–conscious strategies for the military have accelerated in recent years.

In France, an innovative process, called Traffic Light Scheme (TLS) releases airspace reserved for the military at times when civil air traffic overtakes a pre-agreed traffic level. The process contributes to making civil air traffic more direct, efficient and sustainable.

Colonel Christophe Hindermann is the Head of Airspace Division in France’s Ministry of Defence and the main focal point of the civil-military coordination in France. We spoke to him about civil-military cooperation for more sustainable air traffic operations.

Portrait of Colonel Christophe Hindermann in uniform

Colonel Hindermann, could you give us a concrete example of how air forces can contribute to aviation decarbonisation?

Flexible Use of Airspace is a key contributor to optimising the use of airspace, through proper civil-military coordination and strategic collaborative decision-making. An efficient use of airspace optimises the trajectories of civil aircraft, thereby reducing fuel burn and CO2 emissions. The Traffic Light Scheme (TLS) goes beyond the classical Flexible Use of Airspace concept by releasing airspace reserved for the military during time slots when civil air traffic exceeds a pre-agreed traffic level on predefined routes. This process aims to reduce ATM congestion peaks and enables civil aircraft to fly trajectories that are more direct. After 10 years of TLS operations on horizontal airspaces and a successful 2-year trial focusing on vertical flight efficiency in upper airspace, the new TLS is now fully operational. It is roughly used 2 hours per business day, saving approximatively 1,000 t of fuel and 3,000 t of CO2 per year.

How does TLS improve the flight efficiency of civil traffic in practice?

We have built on the FUA principles that we have adapted to our own requirements, to achieve a win-win solution for both sides. At strategic level, we have applied the Advanced-FUA Military Variable Profile Area (MVPA) concept to our main training areas. MVPA volumes can be adapted to either civil or military requirements. Then priority rules are set that the French civil-military Airspace Management Cell applies at pre-tactical level. The real innovation is the establishment of pre-defined traffic thresholds. When these are overtaken, the priority rules are automatically applied without any further Collaborative Decision Making and the airspace is released via the European Airspace Use Plan / Updated Airspace Use Plan. This is completely transparent for the civil airspace users.

Do you see a chance for such initiatives to spread across Europe?

I am personally convinced that TLS is feasible in other parts of European airspace, but we are not the only ones who developed innovative Flexible Use of Airspace solutions: there are interesting experiences all across Europe. We disseminate good practices actively through fora such as the Military Harmonisation Group (MILHAG), the EUROCONTROL Operational Excellence Programme, or the FABEC Joint FUA Task Force more specifically. On top of cooperation, the future will rely on digitalisation, for further optimising flight efficiency with better-informed decisions for the Flexible Use of Airspace and more dynamic execution. This requires better interoperability between airline systems and ATM systems, both civil and military, but this is work in progress.

A Rafale fighter jet pictured in flight, against a blue sky with white clouds. The fighter jet has a pointy nose and triangular wings in the back.

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