On May 15, 2003, at 0815 eastern daylight time, an Agusta A109E helicopter, N7YL, operated by Tri-State Emergency Systems, was substantially damaged after takeoff from the Harbor Creek Heliport, Harbor Creek, Pennsylvania. The certificated airline transport pilot and 2 passengers were not injured. Visual meteorological conditions prevailed and no flight plan was filed for the air medical positioning flight conducted under 14 CFR Part 91. In a written statement provided by the pilot, he stated that while checking the tailrotor driveshaft during a preflight inspection, he was called by the mechanic to look at another item on the helicopter. He placed the flashlight he was using on the V-shaped "strake" on the tailboom, and when he finished with the mechanic, he prepared for departure. The pilot then departed for a local flight and while leveling off at 700 feet, the rotor system experienced a vibration. The pilot executed a precautionary landing to a field, after which he noticed damage to the main rotor and tail rotor blades. He then attempted to locate the flashlight he had used during the preflight to further inspect the helicopter. When he was unable to locate the flashlight, the pilot realized he had left it on the "strake" during the preflight, which damaged the blades during takeoff.