Article 9a 2.

be supported by a safety case;

enable optimum use of airspace, taking into account air traffic flows;

ensure consistency with the European route network established in accordance with Article 6 of the airspace Regulation;

be justified by their overall added value, including optimal use of technical and human resources, on the basis of cost-benefit analyses;

ensure a smooth and flexible transfer of responsibility for air traffic control between air traffic service units;

ensure compatibility between the different airspace configurations, optimising, inter alia, the current flight information regions;

comply with conditions stemming from regional agreements concluded within the ICAO;

respect regional agreements in existence on the date of entry into force of this Regulation, in particular those involving European third countries; and

facilitate consistency with Community-wide performance targets.