On January 18, 2018, about 1605 mountain standard time, a Tukan experimental, amateur-built weight-shift aircraft, N907T, was substantially damaged when it collided with trees and terrain during an approach to Erie Municipal Airport (ELK), Erie, Colorado. The student pilot sustained minor injuries. The aircraft was registered to a private individual and the flight was conducted as a Title 14 Code of Federal Regulations Part 91 solo training flight. Visual meteorological conditions prevailed throughout the area and no flight plan was filed for the flight. The flight originated from ELK about 1600. A flight instructor flew the aircraft with the student pilot and conducted seven landings and takeoffs. The aircraft was operating normally during the dual instructional flight. After the dual instruction, the aircraft was taxied back to a hangar where the instructor pilot explained single pilot operations to the student. The student pilot then took off solo and entered the landing pattern. The instructor pilot observed that the student seemed to lose control on his first final approach and executed a go-around. On the second approach, the instructor observed the aircraft on final. The aircraft collided with trees and the wing struck the ground, resulting in substantial damage. According to the student pilot, while securing the airplane after the accident, he realized that he had inadvertently shut off the fuel valve while on the downwind leg instead of activating the carburetor heat. He stated that the two systems had similar push/pull control knobs that were positioned next to each other in the cockpit. Examination of the wreckage at the accident site by a Federal Aviation Administration inspector did not reveal any pre-impact mechanical with the airframe or engine.