At about 0830 Mountain time, the airplane impacted the ground shortly after takeoff. The pilot/owner and a certified flight instructor were killed. The airplane sustained substantial damage. Visual conditions prevailed. Witnesses reported the takeoff was normal, but on climbout the engine began to sputter. The airplane appeared to “dip” and then recovered, followed by a high-pitched revving sound. Witnesses saw the airplane rocking back and forth, and then the left wing “dropped.” The airplane stalled and entered a dive before impacting the ground.
