I am not 100% sure but I believe he owns it, along with managing and developing it. There are also a few other people involved with running AE, but doing things like running the forums or managing the aircraft database.
The option already exists to go ad free, cost is $20 per year. It is however hidden away, click on your user name to find it.
Yeah, but we are more talking about putting something more firm in place ensuring all money put towards this would get used for development. I can't tell for sure but I assume the $20 donations cover server rental costs.
Doing this, I plan we would also form a dedicated group of people to act on this. Does Yuxi own the site or does he just manage/dev it?