It's 52 eps, right? I'll say about halfway-ish because I don't want you to know exactly when it happens. You should be surprised in case it doesn't happen the same way as in the manga.

(I knew I LJ'd about that event, and my one fma-tagged item pinpoints the episode. Go me in being so obsessed I have to write on LJ about it!...

er, wait, you did the same thing. heh.)