Major fps issues when landing KA-50

So i have a issue with the ka-50, so idk why but when I play the ka-50 I go from 100+ fps down to 14-16fps when I try to land on heli landing area, its super strange because it only happens with the ka-50, no other heli have this issue with my game.

when I repair/resupply the heli I get my fps back.

as I said idk if its WT problem or a hardware problem.

hmm, do you see dust from the ground showing, when the FPS drops?

Also, have you updated your Graphics card drivers recently? - maybe roll them back to see if this helps