Crew Chief An Air Force crew chief prepares an F-35A Lightning II for takeoff at Nellis Air Force Base Nev., Jan. 31, 2019, during Red Flag 19, an aerial combat exercise. SHARE: Download: Full Size (1.98 MB) Tags: Exercises, Air Force, Red Flag Credit: R. Nial Bradshaw, Air Force VIRIN: 190131-F-OD616-0006C.JPG Photo Gallery