On January 21, 2018, about 1545 eastern standard time, an unregistered Mosquito XEL helicopter was substantially damaged after a loss of control and collision with terrain near Loxahatchee, Florida. The non-certificated pilot/owner was seriously injured. The flight was operated in accordance with Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed, and a no flight plan was filed for the flight that departed a private residence. The pilot/owner was performing a test flight. This was his first flight in the accident helicopter. He performed a brief takeoff to a hover maneuver followed by a normal landing. During the second attempted takeoff and hover, the helicopter gained altitude and began yawing to the left. It reached treetop height of about 60 ft and continued to spin before descending and impacting the ground. The single-seat helicopter was purchased by the pilot/owner in a ready to operate condition. It was equipped with a two-blade, semi-rigid main rotor system and was powered by a Compact Radial, MZ202, 60 hp engine. An inspector with the Federal Aviation Administration (FAA) responded to the accident site and inspected the wreckage. The helicopter's skids, lower fuselage, main rotor blades, and tail boom were all damaged during the accident. Review of FAA airworthiness records revealed that the helicopter was not registered and it never received an airworthiness certificate. In addition, there were no maintenance records. At 1553, the reported weather at Palm Beach International Airport (PBI) West Palm Beach, Florida, located 12 nautical miles east of the accident site included: winds from 080° at 16 knots, 10 miles visibility, few clouds at 2,000 ft, broken clouds at 6,500 ft, temperature 24° C, dew point 18° C, and an altimeter setting of 30.14 inches of mercury. According to FAA airman records, the pilot did not possess any FAA-issued pilot certificate. The FAA Inspector reported that the pilot had accumulated about 60 hours of dual instruction in two other make and model helicopters over the preceding 24 months. The pilot's logbook indicated that his last logged flight occurred on August 13, 2016.