Article 2
Tasks of national supervisory authorities 1. The national supervisory authorities referred to in Article 4 of the framework Regulation shall ensure the appropriate supervision of the application of this Regulation, in particular with regard to the safe and efficient operation of air navigation service providers which provide services relating to the airspace falling under the responsibility of the Member State which nominated or established the relevant authority. 2. To this end, each national supervisory authority shall organise proper inspections and surveys to verify compliance with the requirements of this Regulation. The air navigation service provider concerned shall facilitate such work. 3. In respect of functional airspace blocks that extend across the airspace falling under the responsibility of more than one Member State, the Member States concerned shall conclude an agreement on the supervision provided for in this Article with regard to the air navigation service providers providing services relating to those blocks. Member States may conclude an agreement on the supervision provided for in this Article with regard to the air navigation service provider providing services in a Member State other than that in which the provider has its principal place of operation. 4. National supervisory authorities shall make appropriate arrangements for close cooperation with each other to ensure adequate supervision of air navigation service providers holding a valid certificate from one Member State that also provide services relating to the airspace falling under the responsibility of another Member State. Such cooperation shall include arrangements for the handling of cases involving non-compliance with the applicable common requirements set out in Article 6 or conditions set out in Annex II.