4. Where a national supervisory authority is not legally distinct from an air navigation service provider, the Member State concerned shall inform the Commission on the measures it has taken to ensure that the national supervisory authority meets the requirements of paragraph 3 and shall document how its independence is achieved, showing the effectiveness of such independence. To this end, where the national supervisory authority and the air navigation service provider are part of the same administration, the national supervisory authority shall not seek or take instructions from a hierarchical level of that administration having authority over the air navigation service provider, in so far as their tasks under Article 5 and related decisions are concerned.