On November 16, 2013, about 1315 central standard time, a Pearson Dragonfly, an amateur-built gyroplane, N975DF, impacted terrain near the Chambers County Airport (T00), in Anahuac, Texas. The pilot, the sole occupant on board, was fatally injured, and the gyroplane was destroyed. The gyroplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, and no flight plan had been filed. The flight originated from Anahuac about 1300.The following is based on the Federal Aviation Administration (FAA) inspector's report: The gyroplane was in the airport traffic pattern. Witnesses saw the main rotor head separate in flight and the gyroplane impacted terrain about 1 mile southwest of T00. According to friends of the pilot and the mechanic who performed the last conditional inspection, the pilot-owner performed the majority of the maintenance on the gyroplane, and he had recently installed a main rotor head bearing block. Examination of the wreckage revealed the bearing block had been installed upside down. The mechanic said the bearing block was being held in place solely by friction. The pilot was not an FAA-certificated mechanic nor was he a certificated repairman. An autopsy performed on the pilot disclosed the cause of death to be "blunt force injuries."