KC-135 Stratotanker refueling aircraft from Fairchild Air Force Base, Wash., taxi down the runway in an "elephant walk" during a training mission demonstrating total force integration Feb. 23, 2012. Personnel from the 92nd and 141st Air Refueling Wings executed the mission and launched several aircraft. "Elephant Walk" is a historic, uniquely-Air Force term that describes the nose-to-tail, single-file taxi movements of the aircraft synonymous with the nose-to-tail trail of lumbering elephants. (U.S. Air Force photo/Airman 1st Class Taylor Curry)