U.S. Air Force Col. Douglas Thies, 20th Operations Group commander, prepares to fist bump Col. David Vaclavik, 20th Mission Support Group commander, prior to a familiarization flight at Shaw Air Force Base, S.C., May 30, 2017. Thies flew Vaclavik, who has been his friend since college, on a familiarization flight training mission in an F-16D Fighting Falcon. (U.S. Air Force photo by Airman 1st Class Destinee Sweeney)