As we know, TK start 3 weekly A330’s on IST this month. On top of that, there are lots of ad-hoc A330’s on other flights, making 2 daily A330 on plenty of days.
One key date though, 29th August. TK will send 2 B77W, which judging by fares are almost fully booked as it is. There is abnother B77W on 8th August. Seems the route is doing very well at the moment. Surely a 3rd daily is up for consideration again?