EAA Airventure air show planners routinely and safely carryout daily airshows with dozens and sometimes scores of dissimilar aircraft converging over Wittman Field at the same time. One of the keys to safety of such flyovers has been altitude separation for each of the dissimilar types of aircraft. Similarly, when different types of aircraft make continuous orbits of the airfield, they appear to be assigned different altitudes based on their speeds.