Foundations for any general survey must be laid on established fact. In Aviation all facts are difficult to establish with exactitude because of the almost infinite number of variables concerned. In addition, post-war Civil Aviation, in 1948, has not completely emerged from the transition period from war to peace. Converted military aircraft are still in widespread use on the airlines of the World, while ground facilities suitable for commercial Aviation are still under construction everywhere. Many new technical developments are also in course of introduction.
Hence, at present, Air Transport is nowhere near stability. Such annual accounts and statistics as are now available are for the years 1946 and 1947, during which reconversion was at its peak.