Conspicuous by its absence is any mention of flight as something Clark can do.
I don't know if it's canon or fanon that LnC Clark couldn't fly till he was eighteen.
In JSN, Clark says that he's been flying since high school, but I don't think canon mentions anything more specific than that in terms of when he began to fly.
Doesn't he say in ASU that he didn't learn to fly until he was 18? He must have somewhere, because I never have him learn to fly until then in any of my fics. It's also why I assumed he hasn't learn to fly, yet, here.