I have a cordra reinforced butt on my free fly pants for the butt slide, but IMHO if you need padding then you really need to rethink being a tandem instructor. Your students should not be hitting the ground hard enough for you to need butt pading. Kirk
I don't pound them in hard or anything, it just seems like a good idea to protect your tailbone if you know you're going to be sliding in on your ass. Plus I thought it might help save the butt of my FF pants. I'm also hoping it makes sitting in the back of a 182 suck less.
I've always found a cordura butt pad to be sufficient, except the one time I hit a rock sticking up out of the ground, right on my anus, just as we were finishing the slide. Of course the vidiot was only 5 feet away and recording the post jump interview as I was trying to get out of frame so I could cry.