Artikel 9

A designated airline of one Contracting Party may make a change of gauge at a point in the territory of the other Contracting Party only on the following conditions:
(a) that it is justified by reason of economy of operation;
(b) that the aircraft used on the section more distant from the terminal in the territory of the former Contracting Party are smaller in capacity than those used on the nearer section;
(c) that the aircraft of smaller capacity shall operate only in connexion with the aircraft of larger capacity and shall be scheduled so to do; the former shall arrive at the point of change for the purpose of carrying traffic transferred from, or to be transferred into, the aircraft of larger capacity; and their capacity shall be determined with primary reference to this purpose;
(d) that there is an adequate volume of through traffic; and
(e) that the provisions of Article 8 of the present Agreement shall govern all arrangements made with regard to change of gauge.