Immelmann turns or split S's
An interesting question came up in my last WoGs weekend.
To do an immelmann turn or split S you must perform a straight before and after the turn itself. I always thought (rightly or wrongly) that to do another one afterwards you needed to do another set of straights to do another. My opponent however pointed out that he could do a straight then immelmann then straight then immelmann then a straight. For simplicity that's S, I, S, I, S. Looking at the rules as written it would appear he is right.
What do you think?