I'm not sure if this is the correct place to post, but I'll test my luck.
I was flying back and forth to Hong Kong and I noticed there is a three hours difference between the duration of the flight between the going to and coming back.
The flight I'm talking about are TK70
IST - HKG which takes 9h 48 min versus TK71
HKG to IST which takes 12h 21m
I first thought that it's a difference in distance traveled. But it seems that is not (actually the one that is shorted travels a longer distance).
Any explications for this?