Trajectory-based free routing

Validating the benefits of extending free routing into complex airspace and lower vertical limits through modelling and real-time simulations.

The SESAR2020 project PJ 06 focuses on validating the benefits of extending free routing (FRA) into complex airspace and lower vertical limits through modelling and real-time simulations.


The free routing (FR) concept enables airspace users to fly as close as possible to their preferred trajectory, without being constrained by fixed airspace structures or fixed route networks.

FR implementation represents a step towards the less fragmented European airspace targeted by the Single European Sky (SES). It provides airspace users with the possibility to fly their user-preferred routes, in accordance with their business needs or mission requirements.

FR will result in a seamless airspace, enabling more efficient flights, a reduction in airspace user costs. This will promote cheaper travel, increasing personal mobility and trade.

Implementing free routing airspace (FRA) will additionally reduce the greenhouse gas emissions that currently contribute to global warming, thereby creating a greener airspace.

PJ06 partners will validate, through modelling and real-time simulations, both the benefit to AUs and the impact on ATM of this extension of FRA into complex airspace and lower vertical limits.

The corresponding effect on the network of the change of traffic flows, and the need to balance flight efficiency with capacity, are important aspects of this project.

It is hoped that the results will provide evidence that the ongoing FRA implementation across Europe can be extended cost effectively to highly complex environments across all SES airspace.


This project covers the following solutions:

  • Solution PJ06-01 - Optimised traffic management to enable free routing in high and very-high complexity environments
  • Solution PJ06-02 - Management of Performance Based Free Routing in Lower Airspace
    Partners: PANSA (B4), DSNA, EUROCONTROL, INDRA, skyguide, THALES LAS, ON (B4)


FRA was addressed within the SESAR 1 programme but additional R&D activities are required to support the implementation of FRA in high and very high complexity airspace (EU Regulation No 716/2014 mandates FRA above FL 310 from 1 January 2022) and also to extend this implementation below FL310 thereby allowing other AUs to benefit. The European Air Traffic Management Master Plan version 2015 identifies the need for R&D work to support the management of performance-based FR in lower airspace.


DSNA, PANSA Poland and ON (Oronavigacija) Lithuania as B4 Consortium, INDRA, COOPANS, LEONARDO, ENAIRE, skyguide, ENAV, THALES.