Artikel 9

If either of the Contracting Parties considers it desirable to modify any provision of the present Agreement, it may request consultation with the other Contracting Party; such consultation, which may be between the Aeronautical Authorities and which may be through discussion or by correspondence, shall begin within a period of sixty (60) days of the date of the request. Any modifications so agreed shall come into force when they have been confirmed by an exchange of diplomatic notes, which shall state that the formalities required by the national legislation of each Contracting Party have been accomplished.