On October 25, 2014, about 1240 eastern daylight time, a Bell 206B, N418SV, operated by Helix Helicopters, exhibited substantial damage after landing uneventfully at Wellington Aero Club (FD38), West Palm Beach, Florida. The commercial pilot and four passengers were not injured. The local personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the flight, which departed FD38 about 1130. The owner/pilot stated that she took some friends on a pleasure sightseeing flight. After landing the helicopter on a dolly and disembarking the passengers, she observed a large crack on the underside of the passenger side skid. Further examination of the helicopter by a mechanic revealed the following additional damage: impact damage between the main driveshaft and transmission isolation mount; a cracked support at the left forward engine mount; a cracked starter generator mount bracket; and a cracked main rotor yoke. The damage was consistent with a recent hard landing. The owner/pilot stated that there were no hard landings during the sightseeing flight, which was corroborated by a pilot-rated-passenger. The owner/pilot added that 2 days prior to the damage being observed, two instructional flights were conducted by another pilot/flight instructor at Palm Coast, Florida. Following those instructional flights, the owner/pilot repositioned the helicopter to FD38 and did not notice any damage. She further stated that the helicopter was not flown between the repositioning flight and the sightseeing flight. According to written statements from the flight instructor and two pilots receiving instruction, no hard landings occurred during the two instructional flights. Additionally, during a postflight inspection following the first flight, oil was observed around the tailrotor gearbox as the tailrotor gearbox cap had separated. The tailrotor gearbox was then serviced with oil and the tailrotor gearbox cap was secured. A preflight and postflight inspection during the second flight did not reveal any other anomalies.