Aeroflot is a Russian airline — a company that flies people on its planes, not a type of aircraft and not a word for flying in general. You treat it like other airline names: EVA Air, China Airlines, British Airways. It takes a capital A because it is a name. Though actually, it began as the huge state airline of the Soviet Union, so older people may still hear Aeroflot and think of that whole era, not only the company of today. In the news it is one word. You can fly Aeroflot or book with Aeroflot; you would not say an aeroflot the way you say an airport.

俄羅斯航空（店招、新聞常直接寫 Aeroflot；標題也有人縮成俄航）