John J. Bertin, deceased, was Professor Emeritus of Aeronautics at the US Air Force Academy, formerly holding positions at NASA, The University of Texas at Austin, and Sandia National Laboratories. Russell M. Cummings is Professor of Aeronautics at the US Air Force Academy. He is a Fellow of the American Institute of Aeronautics and the Royal Aeronautical Society, and the lead author of Applied Computational Aerodynamics (Cambridge University Press, 2015).