A rooftop landing can be tricky since there is no "ground effect" to facilitate a "in-ground-effect" (IGE) hover, and so, a pilot must determine if the helicopter has enough power for a out-of-ground-effect (OGE) hover. If not, the pilot will make a direct landing from a descent rather than terminate in a hover. A landing from descent is also accomplished when rotorwash during a hover landing might blow things around; other aircraft, snow, gravel. The rotor brake in X-Plane is not realistic since it is either "off" or "on." In reality, it is much like a car's brake pedal: the more it is moved to the vertical, the greater braking action applied. A pilot must be careful on slippery surfaces since aggressive use of the brake can cause the helicopter itself to rotate in the opposite direction. (Newton said it would, too.)