The rising number of airplanes and UAVs requiring connectivity in the sky puts high demands on all types of networks. In areas without DA2GC coverage, such as sea or oceans, the only option is SC. However, the capacity of SC is limited and insufficient in some cases. Therefore, an extension of DA2GC by A2AC and integration of A2AC and SC is a promising solution to improve available capacity. The main aim of this article is to evaluate limits of SC and A2AC in terms of maximum available capacity and maximum range. The results show that A2AC through DA2GC backhauling is able to overcome capacity available by SC on certain conditions while flying close to the mainland. Integration of A2AC and SC can significantly improve data rate available for UAVs and airplanes, especially if the sky cannot be covered by DA2GC only. Our results show that A2AC can provide capacity up to 93 Mb/s, and it can even exceed the capacity of SC when DA2GC and A2AC distances are short. When SC is overloaded, A2AC can be used instead to provide airplanes with capacity of 37 Mb/s up to 432 km DA2GC distance and 340 km A2AC distance. Besides the evaluation of both networks, the article also summarizes and discusses potential challenges and open issues of integration that need to be considered on the way to successful cooperation of both networks.