Flight International and Aviation Week both carry occasional flight tests. Given that there aren't many new commerical planes thyey aren't that frequent but they also carry flight tests of smaller types as well (but still not frequently).
Air Transport World and Airline Business are both aimed at the commercial issues but sometimes provide background to certain decisions.
I'm not sure I can name any non-english language magazines but I see no reason why they won't exist. In the early 1980s I was surprised for find what appeared to be technically oriented magazine on sale in Beijing in Chinese.