Sabiha Gokcen is the second airport on the Asian side of Istanbul.
I don't think it was really neessary to build a second airport in Istanbul. There are very few flights operating at the moment. Most of the flights are charters from mainly CIS. Germanwings is the only one operating regularly from CGN
Another one to start will be a Netherlands based Turkish company called Corendon. They start to fly from Eindhoven on March 19 on a daily basis.
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