The completion at the end of April of FAB CE’s major study into the introduction of Free Route Airspace (FRA) throughout the FAB CE area (“Free Route Airspace – from the Black Forest to the Black Sea”) is a significant work of research, with important findings for FAB CE airspace alliance members and beyond.
FRA is a pivotal element of the European Commission’s Single European Sky programme and according to Implementing Regulation (EU) No 716/2014 FRA will be implemented throughout Europe from 1st of January 
2022. The study is an integral part of the work programme managed by FABCE Aviation Services Ltd, the legal entity responsible for supporting the implementation of the FAB CE programme.
Within the FRA concept aircraft operators can freely plan a route between a defined entry point and a defined exit point without reference to the air traffic services (ATS) route network; every aircraft operator defines its user preferred trajectory according to its business intentions. For all aircraft operators the introduction of FRA, in theory, offers better flight predictability and shorter routes – which means less time in the air, less fuel burn, lower costs and a reduced environmental impact. Savings in distance from these improvements – if applied throughout Europe - could be as much as 25,000 NM a day, according to Eurocontrol figures, which would lead to annual savings of 45,000 tons of fuel, 150,000 tonnes of emissions and EUR 37 million in operational charges to airspace users.
FAB CE members have led the way in introducing the concept within Europe – especially in the challenging areas of cross-border (“X -Border”) operations.
The key benefit expected from the project is to create a clear definition of the operational end technical pre-conditions for a conceived FAB CE X-Border Free Route Airspace.
The study aims to define the operational and technical pre-conditions to implement
the FAB CE Free Route Airspace, including Concept of Operations (CONOPS), the necessary related validation exercises and the required developments and upgrades of ATM systems by FAB CE members. Time frame of the study was September 2015 – April 2017.
Validation exercises of FAB CE CONOPS were divided into Fast-Time Simulations (FTS) - to calculate horizontal and vertical inefficiencies - and Real-Time Simulations (RTS) - to assess specific operational procedures. Special attention was given to the adequacy of ATC support tools, capacity analysis and the situation with active military airspace areas. Throughout the RTS the effects on controllers’ workload and situational awareness were measured.
The results of the simulations led to the following conclusions:
- The unrestricted FAB CE level cross-border FRA concept provides the desired benefits for airspace users in terms of horizontal flight efficiency while no difference could be identified in vertical flight efficiency.
- The non-FRA specific and both versions of the tested FRA specific operational procedures proved to be adequate to handle all – including military – operations.
- The tested versions of areas-of-common-interest concepts cannot be distinguished by significant difference in workload or situational awareness values during their application.
- The different mitigation techniques may need to include a combination of modified sector boundaries, regulation (channelling) of traffic flows and regulation of traffic demand.
- Implementation of additional ATM tools will probably have a beneficial effect on controller workload and situational awareness.
“We also examined the vertical inefficiency in climb, cruise and descent, but we did not find significant difference with the introduction of FRA, which strengthens the assumption that the vertical profiles will not be degraded,” said Martin Stieber, Austro Control, Project Manager of the study.
The Final Simulation Report also concludes that the sector occupancy was an important predictor of the workload, although it was not the only contributor. The distribution of the conflict points, the traffic complexity, the lateral boundaries of the sector and the available system support tools in the system also played key roles in changes of the workload and situational awareness figures.
Multiple recommendations have made by the report for ATC support tools such as variances of the probe function and specific, map-based or time-based support tools that could be essential for handling FRA operations within the areas of common interest.
The study itself has been developed as a baseline evaluation of the feasibility of implementing FRA in the FAB CE area. “It provides the participating ANSPs with a framework for the individual implementation activities rather than a ‘big bang’ implementation approach to FRA,” said Martin Stieber. “We believe a step-by-step approach is considered as the preferred implementation path.”
The study allows now FAB programme management to assess the feasibility of the potential extension of FAB CE FRA operations to neighbouring functional airspace blocks (FABs) as well - particularly to FABEC and Danube FAB.
