It appears that the models have not been built to the Weston specs. The specs stated that there should be 3/16 balsa cheeks at the back with the grain going fore/aft. Then 1/4 balsa doublers inside of these with the grain going vertical. I know my Hype just has what appears to be 3/16 balsa cheeks around the tailplane. Ther next batch will have these specs embodied. I epoxied 1/16 ply sides the same shape as the balsa cheeks to the inside of each balsa cheek. I did this following all your comments on the tail failures. I also epoxied 3/8 triangular balsa to the underside of each tailplane to balsa cheek joint. Those that have had their Hype fail, did it fail within the balsa cheeks or did it fail in the balsa cructh sides further forward. I used the Weston Hi tork 50 motor and pipe and carbon spats/u/c etc and mine came out nose heavy so adding some epoxy and ply to the back is not a probem. I had to mount my batt 3 inches behind the back of the wing on a 1/8 ply plate across the fuz sitting on the lower longerons, I added 3/8 trianular balsa to this joint as well. My C of G is 170mm and it hovers just right. Might move it back a little more to the 180 mm max stated by Weston to see if it helps.