Service members from the US Air Force, Army, Navy, and the Bulgarian Air Force participated in a two-week jump exercise called Operation Thracian Fall in Plovdiv, Bulgaria, from 9-22 October 2011. The exercise is part of semi-annual off-station training to enhance interoperability between the US and Bulgarian air forces and gives US and coalition jumpers an opportunity to hone their battlefield skills together. A US C-130J Super Hercules crew from the 37th Airlift Squadron at Ramstein AB, Germany, along with Bulgarian C-27 Spartan crews often dropped more than 100 coalition service members a day during the exercise.
