It's not that easy to break some airplanes, a lot depends on how much "available G" they have. ThirdWires F-16 is the only one I've broken recently, just for fun. At low level the available G is huge in the transonic zone so becomes breakable if you just yank back on the stick at high speed. Someone will correct me but I think, in general, the break point is about twice the rated G so a plane rated at 7G's might not actually break up until about 14G. Some structural damage/deformation might happen prior to the break point, and it could be enough to write off the airplane. I remember reading somewhere about a Mirage F-1 accidentally pulling something like 15-17G's and still landing safely, although the airframe was a write off. Also, I think some of the ThirdWire FM's, and my own, for that matter, are unbreakable because the available G is less than the actual plane may be capable of. That's to try and keep the pitch response from getting too sensitive at high speeds in my case, and maybe for TW FM's as well. I usually target a maximum of about 12 G's, which still gives the player the option of a "Hail Mary" high G turn.