The pilot was attempting to reposition the helicopter from an off-airport site in advance of an approaching storm. Following an uneventful preflight inspection and engine start, the pilot climbed the helicopter into a hover and turned toward his intended departure path. He then pushed the cyclic control forward and increased the collective pitch in order to clear some approaching trees. The pilot then realized that “appropriate power” was not available, and turned right in order to avoid the trees. The helicopter subsequently settled with power and impacted the brush below, resulting in substantial damage to the airframe. The pilot reported that there were no pre-impact mechanical malfunctions or failures of the helicopter, nor were any discovered during a postaccident examination of the airframe and engine conducted by a Federal Aviation Administration Inspector. The pilot additionally stated that the accident could have been prevented with “better situational awareness.”