The pilot had previously flown 75 to 80 hours in an ultralight controlled by a combination of weight-shift and rudder. On the day of the accident, he and his partner had practiced a series of crow hops in a Teratorn TA. The Teratorn TA was a 3-axis controlled ultralight which had stick-controlled spoilerons and elevator, and a foot pedal actuated rudder. The pilot stated that on his last crow hop, he was flying about 5 feet above the ground across an open field when he found himself inadvertently heading toward a single, 40-foot tree. He was unable to turn away and decided to fly over the tree. A climb was initiated. However, as the ultralight reached about treetop level, the vehicle mushed, then the right wing dropped and the ultralight impacted the ground. This was the pilot's first flight in this aircraft, which he and his partner had recently purchased. He had not received dual instruction in either a two-place ultralight or a certificated powered aircraft. No preimpact or mechanical failure or malfunction was found.