The Windsor Hotel - Site of the first meetings of the Provisional International Civil Aviation Organization

As war hostilities essentially ended on the day before, on the invitation of the Government of Canada, the first session of the Interim Council of the Provisional International Civil Aviation Organization met on 15 August 1945 at 14:30 in the Rose Room of the Windsor Hotel, adjacent to Dominion Square.

Among the twenty country-members of the Council invited, Brazil and Mexico could not arrive on time for the opening meeting. Canada's Minister of Reconstruction C.D. Howe welcomed the Interim Council and noted that this was "the first post-war organization of the United Nations to get under way...". The first session of the Interim Council opened under the temporary chairmanship of the representative of Canada, Mr. A.C. McKim, with Wing Commander P.A. Cumyn as Temporary Secretary General.

At its first session, the Interim Council decided that, to perform its functions effectively and promptly, it should remain in substantially continuous session, with short recesses to enable members to confer with their respective Governments. The agenda and documentation prepared by the Canadian Preparatory Committee greatly assisted the early work of the Organization, and the Interim Council expressed to the Prime Minister of Canada its deep appreciation for the generous assistance given by the Canadian Government in general and the Committee in particular.

A matter of high importance for the Provisional International Civil Aviation organization (PICAO) was the setting of the First Session of the PICAO Assembly. This Assembly was originally scheduled from 21 May until Sunday 8 June 1946, but ended in fact on 7 June. Although the Assembly was held at the Windsor Hotel, Montréal, some of the meetings were held at the Dominion Square Building (10th floor). Mr. Louis de Brouckère, Chairman of the Belgian Delegation, was elected President of the PICAO First Interim Assembly. The Assembly comprised representatives of forty-four Member States, observers from ten non-member States, and eight international organizations. The session closed with two plenary meetings, one on 6 June, devoted to the selection of the site of the permanent organization and the filling of the existing vacancy on the Interim Council (left by the USSR), and the other on 7 June, at which the Assembly considered the final reports of the Commissions.

On 6 June 1946, toward the conclusion of the first PICAO Interim Assembly, Montréal was selected as the permanent headquarters of the Organization, by 27 votes; the other candidates cities obtained respectively: Paris 9 votes, Geneva 4 votes, a city not named in China 1 vote. The choice of Montréal was formally proposed by Chile and was supported by Peru, the United States, United Kingdom and Australia.