Assuming the idle rpm of your setup is where it should be or at least close,the prop size is OK,and I think you just need a little more practice on your approach and landing techniques.The LT 40 like most good trainers is a "floater" to give you time to get your height right as you pass the edge of the field,set up your glide path as you slow the plane with the elevator and do a perfect "10" flare and landing!