The Cubs they use for this are highly modified. For example, the [url=
http://www.pietschaircraft.com/airshows/"Jelly Belly" Cadet[/url] has a fake left aileron (and it flies perfectly well without it) that comes off during the "flight". Kyle just has steel scrape plates on the wingtips of his Cub. Scares the crap out of some people when they see it for the first time (including myself). It takes an EXCELLENT pilot to fly a plane that badly and not do any damage to it. Just look at how long on that last landing he's able to keep it up on one wheel. That is not something a "typical" pilot is capable of doing.
Kyle however is an EXCELLENT stick and does this routine very well. You can see more about him on the main site -
http://www.franklinairshow.com/
BTW, if you want to see a really cool performance, try and see one of his brother-in-law Matt Yonukin's night performances in his dad's Beech 18 (go here -
http://www.franklinairshow.com/Our%20Acts.htm and scroll down about 2/3 of the way down the page to "Night Twin Beech 18"). I saw that in person 2 years ago at AirSho and it was AWESOME. (Video:
http://www.youtube.com/watch?v=b-ihRSHKWz8)
As an aside, these gentlemen are sons of the late Bobby Younkin and Jimmy Franklin, sadly killed in a mid-air collision while flying a duo aerobatic act in Canada.
http://www.franklinairshow.com/Memorial.htm I then unfortunately watched the 3rd member of their team, and close family friend to them, Jim LeRoy pass away in an accident at the Dayton Air Show two years later.