Technically speaking, you've made a plane that doesn't stall then, through some combination of CoM/CoL/CoT. Planes in this game will absolutely stall, some more cleanly than others. Even in real life though, some aircrafts' stall characteristics are simply dropping the nose and diving, while others stay more or less in the same attitude and simply start descending.

I game itself have stall effect but its not that realistic

The game is over, and it’s way too late to update the physics.