459th Air Refueling Wing KC-135R Stratotankers conduct an elephant walk during an alert exercise at Joint Base Andrews, Maryland, March 5, 2017. The term “elephant walk” has been used since World War II when large numbers of aircraft would line up for rapid response take-off. Onlookers said the procession looked like elephants headed to a watering hole, and the name has been part of the U.S. Air Force lexicon ever since. (U.S. Air Force photo/ Senior Airman Philip Bryant)