On June 9, 2002, at 0027 central daylight time, a Bell 206L-3 single-engine helicopter, N103AE, was substantially damaged when its tail rotor struck trees during an approach to a landing zone near Dover, Arkansas. The helicopter was registered to and operated by Air Evac EMS, Inc., of West Plains, Missouri. The commercial pilot and two medical crewmembers were not injured. Dark night visual meteorological conditions prevailed, and a company VFR flight plan was filed for the 14 Code of Federal Regulations Part 91 positioning flight. The flight originated from Paris, Arkansas, on June 8, 2002, at 2358. The 5,055-hour pilot reported that when the helicopter neared the landing zone (LZ), a light from a flashlight was observed in the vicinity of the proposed LZ. The helicopter over flew the LZ, and the pilot initiated an approach from the south. The pilot determined the helicopter was too high for the approach and initiated a go-around. On the second approach, while using the landing light, the pilot was leaning forward and scanning the area ahead when he "felt the aircraft shudder," and then realized the helicopter was in a high sink rate. The pilot applied power to arrest the descent. The helicopter had "just turned 90 degrees when it stabilized; however, not before striking a tree or trees." The pilot applied additional power to climb above the tree line. "Control response was normal except for excessive vibration in the foot pedals, resonating through the fuselage." Due to rough terrain, low illumination, and obstacles, the pilot elected to fly the helicopter to the Russellville Regional Airport (RUE), Russellville, Arkansas, located approximately 18 miles south of the landing zone. The helicopter landed at the RUE without further incident. According to a crewmember, the landing light was on and created a limited view of the LZ. During the approach, he lost sight of the LZ, but could still see the reflection of light from the LZ crew off the front bubble of the helicopter. He called out to abort the landing, and the other crewmember starting yelling "trees." The pilot stopped the descent, and performed a 90-degree right turn. One crew member noted "moderate" vibration during the flight to RUE. Examination of the helicopter, by an FAA inspector, revealed that the tail rotor gearbox was partially separated from its mount, and both tail rotor blades were damaged. At 0053, the weather observation facility at the RUE, reported the wind calm, 7 statute miles visibility, a few clouds at 1,100 feet, and an altimeter setting of 30.01 inches of Mercury. The temperature was 70 degrees Fahrenheit, and the dew point was 66 degrees Fahrenheit.