Missouri Airman, St. Joseph native promoted to colonel Published Sept. 12, 2021 By Senior Master Sgt. Michael Crane ST. JOSEPH, Mo. -- Lt. Col. Jason Horn, commander of the 139th Medical Group, was promoted to the rank of colonel on Sept. 11, 2021 at Rosecrans Air National Guard Base. Horn became the medical group commander in January. As commander, he is responsible for over 80 medical Airmen ensuring the medical readiness of the wing’s 1,100 members. His previous position was deputy commander of the 139th Maintenance Group. Before that, he served in the medical group as a medical service corps officer and the chief of administrative services. Horn joined the U.S. Air Force in 1988 as a C-130 cargo aircraft loadmaster. He later transferred to the Missouri National Guard’s 139th Airlift Wing in 1992.