20191006018789A

Aircraft was performing aerobatic maneuvers to add to the phase ii capability list. During a 4G recovery, the aircraft entered an overspeed condition and experienced subsequent elevator flutter which malfunctioned the flight control. During aerodynamic flutter of the elevator the right wing spoiler malfunctioned and deployed cause more induced drag and unstable control of flight. The crew was able to establish and maintain control of aircraft after a few moments, they elected to land in the desert rather than bail out via parachute since they were able to maintain limited positive control of the aircraft. As aircraft passed through approximately 10' AGL, the rate of descent increased and aircraft main wheel impacted a small berm prior to the planned touchdown point, the aircraft tail section broke off and the aircraft fish tailed to the right coming to rest perpendicular to the path of landing resting on its left wing. One pilot experienced back pain\ and was transported to the hospital for medical review and was released with no issue but muscle soreness. No corrective action needed for the pilots as this a was testing platform in a non-populated area for expanding the maneuvering capabilities of the aircraft as required by their operating limitations.