Treaty of Saint-Germain-en-Laye/Part XI
The aircraft of the Allied and Associated Powers shall have full liberty of passage and landing over and in the territory of Austria and shall enjoy the same privileges as Austrian aircraft, particularly in case of distress.
The aircraft of the Allied and Associated Powers shall, while in transit to any foreign country whatever, enjoy the right of flying over the territory of Austria without landing, subject always to any regulations which may be made by Austria, and which shall be applicable equally to the aircraft of Austria and to those of the Allied and Associated countries.
All aerodromes in Austria open to national public traffic shall be open for the aircraft of the Allied and Associated Powers, and in any such aerodrome such aircraft shall be treated on a footing of equality with Austrian aircraft as regards charges of every description, including charges for landing and accommodation.
Subject to the present provisions, the rights of passage, transit and landing provided for in Articles 276, 277 and 278 are subject to the observance of such regulations as Austria may consider it necessary to enact, but such regulations shall be applied without distinction to Austrian aircraft and to those of the Allied and Associated countries.
Certificates of nationality, airworthiness or competency and licences issued or recognised as valid by any of the Allied or Associated Powers, shall be recognised in Austria as valid and as equivalent to the certificates and licences issued by Austria.
As regards internal commercial air traffic, the aircraft of the Allied and Associated Powers shall enjoy in Austria most-favoured nation treatment.
Austria undertakes to enforce the necessary measures to ensure that all Austrian aircraft flying over her territory shall comply with the Rules as to lights and signals, Rules of the Air and Rules for Air Traffic on and in the neighbourhood of aerodromes, which have been laid down in the Convention relative to Aerial Navigation concluded between the Allied and Associated Powers.
The obligations imposed by the preceding provisions shall remain in force until 1 January 1923, unless before that date Austria shall have been admitted into the League of Nations or shall have been authorised by consent of the Allied and Associated Powers to adhere to the Convention relative to Aerial Navigation concluded between those Powers.