Avia Special is based at Waltham, operating Tiger Moths and a Cap 10. Avia has a Zlin but it has not been coming out to play for a while (I think that it's having its bits fiddled with). There are a number of aerobatic operators at Waltham, with Caps, Pittses, Moths, and at least one Chipmunk. Also several Yaks and Jungmanns (Jungmennen?), which I am told are mighty fine machines, although none, I believe, operated by an instructional outfit. Enquire at WLAC for details.