Two U.S. Air Force B-1B Lancers deployed to Andersen Air Base, Guam, and two F-15K Slam Eagles assigned to Daegu Air Base, Republic of Korea, fly over ROK skies Sept. 21, 2016. The flight was the closest a B-1 has ever flown to the border between the ROK and North Korea. The B-1 is the backbone of the U.S. long-range bomber mission and is capable of carrying the largest payload of both guided and unguided weapons in the Air Force inventory. (Republic of Korea air force photo by Chief Master Sgt. Kim, Kyeong Ryul)