|I agree with Howard, at least as the play is presented in NY. There are conversations, and then there are statements like, "If I had told him ...," etc. I think the reality is supposed to be that they don't interact. Check out the NY Times review. It expresses a similar sentiment.
Yes, T.J. would not want to fly because he doesn't want to leave a trace of where he's going (AWOL). I don't remember him saying he couldn't take a plane, but that's the sense I got.