After a satisfactory 55-minute training flight in a Robinson R22 Beta that had incorporated numerous takeoffs and landings, the instructor assessed that his 41-hour PPL(H) student pilot handled the helicopter competently and was ready for his first solo. He reminded the student that with no instructor occupying the left seat, the helicopter’s centre of gravity would move right and aft, so the cyclic stick would have to be positioned to the left and forward to compensate, and that gentle control movements should be made during lift off. The student adjusted the cyclic stick to what he thought was the correct position and raised the collective, but was unable to prevent the helicopter rolling quickly onto its right side and striking the ground. The instructor reported that the pilot kept the helicopter straight through correct use of the yaw pedals but did not apply sufficient left cyclic control to compensate for the change of centre of gravity. The pilot, who had been trapped in his seat with minor injuries to his hands, was helped to escape by the instructor, who later attributed the accident to dynamic rollover – a phenomenon the pilot had been briefed about in the classroom and pre-flight. The AAIB has reported on four other accidents in the last ten years that have involved dynamic rollover, three of which occurred during a student pilot’s first or second solo flight in an R22 Beta, while the fourth occurred to an R66 during a student pilot’s first solo on type.