Staff Sgt. Johnnie Yellock Jr. parachutes down after completing his final free fall jump before being medically retired Oct. 16, 2013, at Hurlburt Field, Fla. Yellock endured 28 surgeries and two years of intense physical therapy to be able to walk again after his vehicle was struck by an improvised explosive device during a 2011 deployment to Afghanistan. Yellock is a 23rd Special Tactics Squadron combat controller. (U.S. Air Force photo/Staff Sgt. John Bainter)