Optimised descent profiles generate fuel savings across Europe

A consortium of European air navigation service providers (ANSPs) and airlines has optimised numerous arrival flows to nine airports in Europe. A total of 11,467 demonstration flights were conducted. Half of the 33 analysed flows have already been permanently implemented; seven are published in the Aeronautical Information Publication. Real savings achieved with the project’s demonstration flights amounted to 86 tonnes of fuel savings and a reduction of 270 tonnes of CO2 emissions. On an annual basis, the 33 optimised flows have the potential to erate fuel savings of 3,400 tonnes, which equals more than 10,700 tonnes of CO2 emissions according to calculations by EUROCONTROL.

“The aim was to develop more efficient descent profiles and reduce the environmental impact in busy and complex airspaces and across borders without compromising safety and capacity aspects”, says project manager Ilhan Akin, DFS Deutsche Flugsicherung.

The optimised decent profiles (ODP) project, which was co-funded by the SESAR Joint Undertaking, began its work at the end of 2014 and has just published its final results. It was conducted under the leadership of the German ANSP DFS together with the ANSPs of Austria (Austro Control), France (DSNA) and Switzerland (skyguide), as well as EUROCONTROL’s Maastricht Upper Area Control Centre (MUAC).

Air France (plus HOP!), Deutsche Lufthansa (together with the affiliated Austrian Airlines and Germanwings) and Swiss International Airlines conducted the demonstration flights to the airports of Basel, Berlin Tegel, Frankfurt, Geneva, Munich, Strasbourg, Stuttgart, Vienna and Zurich.

The optimum arrival is a continuous descent, which does not require considerable engine power and thus a reduced amount of fuel. In highly-frequented airspaces, which are shaped by national borders and handover points, this optimum is not always possible. Existing arrival flows can, however, often be improved. For example, instead of fixed handover points, level windows can be defined, which are then programmed in the flight management system of the aircraft. Another way of improving vertical flight efficiency is to remain at cruising altitude for a longer period of time before descending, since fuel consumption is lower at higher levels. The project also used, for example, flexible seasonal or runway dependent handover procedures.

“The project has shown that each and every improvement counts. The optimisations generate fuel savings and thus contribute to a more sustainable air transport in Europe. For the implementation of optimised profiles on a broad basis, a framework and standards need be further developed in close partnership with the airline operators,” explains Akin.

Florian Guillermet, Executive Director of the SESAR Joint Undertaking remarked: "The ODP project represented an excellent opportunity to demonstrate more widely the considerable savings in terms of fuel and emissions that are possible with optimised arrival flows. It is clear that procedures like these will be key to achieving a high performing aviation across Europe in the coming years.”

More about the optimised descent profiles project including a flow example are explained in this video