The main objective of the airspace design is to maximise the efficient use of airspace, whilst maintaining the level of safety applicable to air traffic operations within such airspace, with delineation free of national borders. In order to achieve this objective, the airspace design and structure will be based on common criteria as regards lateral and vertical delineation and designation. In the context of the DANUBE FAB Agreement, “DANUBE FAB airspace” consists of Bucharest FIR and Sofia FIR.
Both BULATSA and ROMATSA gradually implemented Free Route Airspace (FRA) within their individual airspace in November 2013 during night hours and on 30 March 2017, DANUBE FAB ANSPs, ROMATSA and BULATSA, together with HungaroControl (member of FAB Central Europe), introduced major changes in the airspace structure of the three States, by implementing South Eastern European Night Free Route Airspace (SEEN FRA) project.
In stepping forward towards the implementation of H24 Free Route Airspace (FRA) within DANUBE FAB, BULATSA and ROMATSA have commissioned EUROCONTROL to support this action with a prototype and full-scale real-time simulation validation (RTS), which was completed from October 27 until November 12, 2015 at the EUROCONTROL Experimental Centre in Bretigny/France.
The RTS simulated Free Route Airspace (FRA) across the whole DANUBE FAB airspace which involved a total of 18 sectors each operated by full sector teams (one executive and one planning controller). The simulation provided evidence that FRA can be expanded out of the current night-time FRA into H24 FRA on a seasonal basis (from winter, spring to summer) if controllers are supported with a set of advanced ATC tools.