The pilot was taxiing the aircraft for takeoff at the time of the accident. He had just completed refuelling at the fixed fuel bowser and was turning the aircraft to the right when it collided with a refuelling cart that had been positioned to refuel a regular public transport aircraft that was expected to land shortly. The impact crushed a section of the wing's leading edge and then, as the cart rolled over it punched a hole in the lower surface of the wing fuel tank. The cart had been repositioned by the fuel agent between the time the pilot completed refuelling and when he taxied the aircraft. The cart had not been there when he taxied in and he was not expecting it to be there when he taxied out. The Glassair aircraft has a tailwheel and forward visibility is partly restricted. The pilot was speaking to the crew of the regular public transport aircraft, to establish their intentions, as he taxied out and this probably distracted him. He also reported that he was not feeling well and this may have reduced his concentration.