On April 12, 1994, approximately 1300 Pacific daylight time (PDT), a Bell 47G-2 helicopter, N2865B, collided with the terrain while hovering at Portland-Troutdale Airport, Troutdale, Oregon. The certified flight instructor and his student were not injured, but the aircraft sustained substantial damage. The local instructional flight, which departed the same airport about 15 minutes earlier, was in visual meteorological conditions at the time of the accident. No flight plan had been filed, and there was no report of an ELT activation. According to the FAA inspector who responded to the scene, the dual student, who had a total time of 3.5 hours, was practicing a hover about three to five feet above the ground when the helicopter began a deviation from the desired flight attitude. The instructor took over from the student, but the tail rotor impacted the ground before the instructor was able to complete his desired remedial action. After a post-accident inspection of the aircraft, this same inspector said that he could find no evidence of pre-impact malfunctions or anomalies. The Troutdale Surface Analysis (SA), taken about five minutes prior to the accident, showed that there were rain showers of unknown intensity in all quadrants, and the flight instructor reported that the winds, which he said were gusting to 10 knots, were coming from an "unusual" direction. The instructor said that Troutdale Airport was "...notorious for having very unusual wind directions, speed, turbulence, and wind shear."