The non-rated pilot reported that he was landing the weight control shift aircraft. While on a final approach, about 40 ft above the ground, he increased the engine power to arrest an excessive descent rate. The rapid descent continued, and the front tire struck the edge of the runway. As a result, the front wheel assembly “broke” and got jammed on the throttle cable, and with its weight on the cable, set the throttle setting to full. The aircraft tookoff and became airborne. The pilot safely maneuvered the aircraft at full throttle around the traffic pattern and initiated a power off landing north of the runway in the dirt field. Shortly after touchdown, the aircraft “somersaulted” once before coming to a stop. Both wings were substantially damaged. The non-rated pilot reported that there were no preaccident mechanical failures or malfunctions that would have precluded normal operation.