While aboard the Concorde at Mach 2.05 and 60,000 feet, I flew a small stick and tissue, rubberband-powered model airplane from the rear of the airplane toward the front. In accordance with Einstein's theories, the velocity of my model airplane as seen from earth, is the sum of the velocity of Concorde (approx. 1400 miles per hour) plus the velocity of my model airplane (approx. 10 miles per hour). My model airplane thus traveled faster than the supersonic Concorde.