The pilot attempted to land the helicopter on a landing cart. As the helicopter's skids contacted the cart, the helicopter began to slide forward and to the left. The pilot aborted the landing and brought the helicopter back to a hover. During the maneuver, the tail boom stinger contacted the landing cart and the helicopter nosed over. The helicopter touched down and rolled on to its side, causing substantial damage to the tail boom, fuselage, and rotor system. The pilot reported a variable wind and a developing tailwind during the landing.