TRAVIS AIR FORCE BASE, Calif. --Tech. Sgt. Francisco Guerrero-Vasquez, flight engineer with the 312th Airlift Squadron, performs a pre-flight "walk around" inspection of a C-5B Galaxy Aug. 11, 2014, at Travis Air Force Base, Calif. The C-5 Galaxy is a heavy airlifter with intercontinental range. It is the largest U.S. military aircraft, capable of carrying more than 270,000 pounds of cargo. (U.S. Air Force photo/Lt. Col. Robert Couse-Baker)