I came to say the same as katonic I’m afraid, I think 6-12 months is a really hard time to fly. If you could do any earlier maybe 4 months, or if not it may be better to wait a bit in my experience.
We flew to Australia when DS was 4 mths old. People thought we were mad, but the whole experience was really not too bad at all. He dipped in and out of sleep, breastfed, was easily settled in the bassinet, was much easier to entertain, and easy to be carried around in the sling at the airports and for the transfer. In Aus, I mainly kept him in the shade, he didn’t pull off his Sunday, didn’t have to worry about what he would be eating (he wasn’t on solids yet) and he was happy enough in the sling where he mostly slept, he wasn’t but in a particular routine so fitted in with whatever.
We did another, slight shorter flight (6hrs) when DS was 9/10 mths. Longest 6 hrs of my life. He was crawling and teething by then, and much more fidgety and wriggly on the plane. He wouldn’t entertain the idea of the bassinet at all, he was unsettled with his ears popping and his teeth bothering him, I could hear the tuts and signs from people around me on the plane.
When we reached our destination, again in was a bit more tricky, he wanted to crawl and cruise everywhere and was frustrated being in the sling for long periods, it was more difficult to sort out his eating, he kept pulling off his sun hat even when it was fastened so I was always worried about him being exposed to the sun, he was in more of a routine than he had been at 4 months so evenings were more limited with what we could do.
We avoided doing a longhaul flight again until he was 2 1/2, so, as Pp have said, at least he could watch the IPad then!