UH-60 Black Hawk and CH-47 Chinook helicopters arrive to pick-up U.S., Greek and Canadian troops before participating in night air assault training during exercise Swift Response at Bezmer Air Base, Bulgaria, July 21, 2017. The exercise is part of the Saber Guardian 17 exercise. The helicopter crews are assigned to the 10th Combat Aviation Brigade. Army photo by Spc. Thomas Scaggs