Colombian and U.S. Air Force pilots perform pre-flight checks on an A-29 Super Tucano during Exercise Green Flag East at Barksdale Air Force Base, La., on August 17th, 2016. The exercise provides a simulated combat environment for both aviators and maintainers to hone skills necessary for real world operations. (U.S. Air Force photo / Senior Airman Mozer O. Da Cunha)