I . Historical survey The legal status of aircraft is a problem that has given rise to innumerable questions ever since the earliest years of aviation. But the majority of these questions only relate to certain aspects of the legal status of aircraft, and the problem as a whole has hardly been studied at all. The evolutionary process in the study of a number of facets of the problem is outlined below. Nationality The question of the nationality of aircraft has always received a lot of attention. As far as the principle is concerned, there can be little dispute on this point nowadays. The subject of the nationality of aircraft was discussed at the aviation conferences which led to the Paris Convention in 1919, the Ibero-American Convention in 1926, the Havana Convention in 1928 and the Chicago Convention in 1944. According to Article 6 of the Paris Convention of 1919, an aircraft possesses the nationality of the State on whose register it is entered. The Ibero-American Convention of 1926 and the Pan-American Convention signed at Havana in 1928 start from the same principle.