If you are an aviation enthusiast, you surely have asked yourself this question before – which are the most successful aircraft designs? Which planes have the highest production rate, and which ones make up the backbone of today's aviation industry? To answer all these questions, one should progress gradually. First, it is safe to state that the most popular aircraft types have been produced by either Airbus or Boeing, which currently make up a duopoly in the aircraft manufacturing industry (although the status quo might change sooner than one might think).