Around the same time, the Axis defeat at Stalingrad and North Africa, made the collaboration with resistance groups in the Balkans more important. British PM Winston Churchill had obtained ten Halifax bombers to add to the four Liberators and ease the delivery of military aid and in Apr 1943 sub-missions with Mihailović's commanders throughout Serbia were established. On 27 May 1943, Operation Typical, the first dedicated mission to partisans' HQ was dropped at the height of a large German offensive Operation Schwarz which aimed to destroy them. Both missions by now had American (OSS) representatives, Bailey's had Capt Mansfield, and Deakin's had Lieut M.O. Benson.