Originally Posted by
ISTFlyer
This is because TK 800 is a triangle route. That's why most seats are blocked until OLCI or airport check-in.
They don't want an IST-BOG-PTY and a BOG-PTY-IST passenger to choose the same seats for the same flights.
Make sense but I finally managed to select the seats through the TK app. I pulled up my booking and selected 1K and 2K, the only 2 seats available, saved and closed the app. Opened up the app and pulled up the booking again to change seats and this time it showed the entire J class empty so I changed to the seats that I wanted and saved. What's more strange is I repeated the process and my new seats were saved but it again showed the entire J cabin blocked out. I'm not sure what's going on but I managed to secure the seats I wanted.