On June 2, 1944, 130 American B-17 Flying fortress bombers, accompanied by 70 long-range P-51 fighters, took off from airfields in southern Italy and attacked the major railway junction of Debrecen in Eastern Hungary. This bombing of a target far removed from the Western allies ' air force bases was made possible by an agreement with the Soviet Union: after completing the combat mission, the American planes did not reverse course, but headed East. The bombers landed at Soviet airfields near Poltava and Mirgorod, while the fighters landed at Pyryatyn. The RAID on Debrecen was the beginning of a series of American air strikes on targets in the Eastern part of the territory controlled by Germany and its European satellites.
The operation with the Shuttle movement of American bombers between airfields in Italy, England and Ukraine was codenamed "Frantic" and lasted from June to September 1944. About 1,300 U.S. air force personnel were transferred to the three Soviet airfields assigned to it.