Struggling to read the French (both being out of practice and the reproduction not being entirely clear), but there's something even more interesting buried in there. It's talking about this as an alternative to building huge inland flying-boat ports because many major cities aren't on the coast.
In 1946 the flying-boat wasn't obviously obsolescent, and the long range routes to the Far East colonial possessions and Dominions (India, Malaya, the Dutch East Indies, Indochina Australia and New Zealand, and Indochina) were still vital and still largely seen as best suited to flying-boats (look at the development work on the Saro Princess), but a flying-boat can't fly from London or Paris (or not without difficulty anyway). So either you use two aircraft and change over somewhere, or you find a way for large flying-boats to land on terrestrial airfields by making them amphibians, and this is an idea for doing that, when fitting conventional retractable undercarriages would have been difficult.
Interesting idea, but about a decade too late.