Two F-15SG fighter jets from the 428th Fighter Squadron at Mountain Home Air Force Base, Idaho, fly above a storm cloud at Davis-Monthan Air Force Base, Ariz., July 7, 2015. The 428th FS was established by the Peace Carvin V program, a partnership between the U.S. Air Force and Republic of Singapore Air Force to training the RSAF pilots, weapons systems operators, ground control intercept officers, and maintainers to be able to operate their fleet.