St Elmo's Fire Airmen experience St. Elmo's fire while flying a KC-10 aircraft into a thundercloud from an undisclosed location, March 22, 2017. St. Elmo's fire occurs when the electric field around the aircraft ionizes air molecules, producing sparks. Air Force photo by Senior Airman Brian Kelly SHARE: Download: Full Size (4.1 MB) Tags: Air Force, training, Airmen Credit: Senior Airman Brian Kelly VIRIN: 170322-F-ZZ999-002E.JPG Photo Gallery