On September 1, 1994, at 2210 central daylight time, a Bell 206- L4 helicopter, N2064J, was substantially damaged during landing near Hurst, Texas. The certificated flight instructor and commercial pilot receiving instruction were not injured. Visual meteorological conditions prevailed for the dark night instructional flight. In the instructor's pilot/operator report, he stated the pilot was having difficulties keeping the helicopter aligned with the runway prior to touch down. The student had completed 3 autorotations with a 180 degree turn. On the fourth autorotation, the helicopter was not aligned. While the instructor pilot attempted to correct the helicopter's alignment, it touched down with the nose left of centerline. The tailboom flexed, resulting in wrinkles in the tailboom skin. According to the pilot, the helicopter touched down hard in a level attitude with the nose to the left.