The Cermark Pitts is a great flying aircraft. There have been a few stories going around that they have been loosing their upper wing due to upper wing aileron flutter. When over powered, I am inclined to believe that, as I am seeing many that are GROSSLY over powered. The upper ailerons are not directly powered by servos, but by inter-connecting push rods from the lower ailerons. The additional linkage between the lower and upper ailerons tends to develope extra slop, and it's the sloppy linkage that allows the flutter. Be sure to use the outter holes in the extra long control horns that Cermark gives you, and insure that everything is snug.

The upper wing is attatched by two blind nuts that are mounted at the cabane junction. These should be strengthened. I wrapped these junctions that enclose the blind nuts with 60 lb kevlar, and then epoxy coated the wraps. These multiple wraps of kevlar are stronger then steel.

Above all, don't overpower it. I'm using a Thunder Tiger 1.20 two stroke engine that makes for a nice combination. It's probably the nicest Landing airplane that I own,