Eastern Europe is probably stretched out already potential-wise since they have almost everything counting as small town in their network.
Ukraine still has some room to grow. Currently, 6 cities are served (KBP/IEV, ODS, LWO, HRK, OZH, KHE) with a total of around 150 all-year weekly regular flights from IST, ESB, ADB and seasonal regular AYT, BJV on top of that.
5 more unserved airports are likely to have the demand for daily service to IST:CWC
, Chernivtsi - there's a runway surface issue, only A319/B737-700 can land/take off, A220 would do well. The city has many ties with Israel and the Mediterranean European countries.VIN
, Vinnytsia - serving an agglomeration of mid-sized cities in central Ukraine, a huge demand peak in September with many pilgrim pax from Israel (enough for several 747 charters).DNK
, Dnipro - an airport in a big city with the airport owner greed issues, who locked it up for almost everyone, but his Ukraine International Airlines.IFO
, Ivano-Frankivsk - probably the city with the fastest developing economy in Ukraine, many ties with North America, but the same person as in DNK controls the gates. A couple of years ago TK used to fly there only to be pushed out the door 3 weeks after the service started.MPW
, Mariupol or ERD
nearby - a very special case of an airport close to the separation line in the Donbas. The government of Ukraine is keen to open it up to compensate for the demolished DOK. Considering that there is significant international premium demand (OSCE, UN, diplomats, etc), and TK risks flying to destinations like Mogadishu or Baghdad, it is an option as well.
PLV, RWN, NLV, KWG, ZTR, TNL - each serving around a million inhabitants in a 100 km radius, and will probably be in the second basket. I would expect them to welcome TK or PC anywhere between 5 to 10 years from now.