capi3101, lordcirth thanks fo yur answers.
I'm afraid i didn't balance my plane before reentry and i had the center of gravity too close to my tail after burning more than 90% of my fuel. I lost control after i exceed the critical angle of attack having about 2000 m/s at 40 km or lower.
I built two similar aircrafts. With one i was close but finally i burnt during reentry. It was nice.
With second i exceeded AoA of ~15 -20deg in similar conditions and my plane desintegrated due to G-forces and aero pressure as i think it shoud. I was pleased Really.
I'll test some other aircrafts. I stand by what I said, this mod, just an idea of this mod is just fantastic. It's easy to modify some aspects of flights in a vacuum, additional parts, life support etc. but this mod is something. Fluid mechanics in the atmosphere is the weakest part of stock KSP .
cheers