Hi all, I have to tell you that every mod I've done lately had a tail. The reason I'm bringing this up is I just tried to fly a mod'ed plane w/o a tail and it didn't fly well. In dead air, my mods still seem to require the tail to be lower than the wing. I thought that I was just battling the wind. So in dead air an 18" SILK ribbon will do the job. For clothe and nylon ribbon I would guess around 12", maybe less. Tim