As the subject of this post asks. What makes a pattern plane a pattern plane. They all seem to be long in the fuse. narrow in the wing. and just pain racy lookin to me.
I love the looks of pattern ships so I thought i'd just try to find a definition of a pattern plane.
Thanks

Pattern planes are defined only by size and weight. Less than 2 meters in length and span and less than 5 kilograms (11 lbs). Within those simple rules you have to design a plane that flies the current maneuvers as best as possible.

Just to round out Diablo's succinct and technically correct description, I will only add that pattern planes are designed by expert flyers/designers, focusing on flight characteristics that favor the perfect execution of the exacting AMA and FAI specifications for aerobatic maneuvers. If a pattern flyer designs a plane thinking it will fly pattern as well as or better than what's already in use, and builds and flies it (and re-designs and re-builds and re-flies it) and it works, and other pattern flyers want to fly it as well, then it's a pattern plane. They share a strong family resemblance because they are so highly evolved. I used to think they looked rather odd, because I flew mostly scale designs, which don't resemble pattern planes much at all. But after tasting pattern flying myself, they look as natural as any other thing that flies.