An F-35A Lightning II arrives at Edwards Air Force Base, California, Aug. 1. The aircraft, Air Force serial number 338, is the first of six F-35s the 461st Flight Test Squadron and F-35 Lightning II Integrated Test Force will receive in the next few years. The upgraded fleet will be used to test the Technical Refresh 3 and Block 4 configurations of the Air Force’s newest fighter that will create tactical and operational advantages over peer competitors. (Air Force photo by Chase Kohler)