
A Bulgarian air force MiG-21 pilot taxis past U.S. Air Force F-16 Fighting Falcons April 19, 2012, at Graf Ignatievo Air Force Base, Bulgaria. Two U.S. fighter squadrons and more than 500 personnel are deployed here from the 31st Fighter Wing, Aviano Air Base, Italy, in support of Thracian Star 2012. The month-long exercise is geared toward strengthening partnerships and increasing interoperability between NATO allies.