After looking at the game table (board) I can understand why this idea is intriguing. But after thinking a bit, Russia & GB can very easily keep any the black sea ship free with their air force. At least if I was Russia, I would sink anything built there. Also would love Germany to spend that kind of $$ ion an IC & navy instead of tanks, art & inf……still, it might be fun to give it a go sometime.
I once built an airbase in Romania in a Tech game where I had rockets and paratroopers. If you had that, I guess you could protect a TT with scrambled fighters and hit Caucusus from the Ukraine.