Schlacht von Rschew
In January 1943, Leie transferred as "Gruppenkommandeur" to I. "Gruppe" of JG 51, based on the Eastern Front. Leie had received the transfer-order on 6 January and arrived at his new unit on 17 January which at the time was based at Isotscha near Nevel. That day, Leie's predecessor as "Gruppenkommandeur", "Oberleutnant" Rudolf Busch, was killed in action when he collided in mid-air with "Geschwaderkommodore" "Oberstleutnant" (Lieutenant Colonel) Karl-Gottfried Nordmann. At the time of Leie's arrival on the Eastern Front, Soviet and German forces were engaged in the Battle for Velikiye Luki and in the Battles of Rzhev in the sector of JG 51 area of operation. On 28 January, I. "Gruppe" was forced to give up its airfield at Isotscha and moved to an airfield west of Oryol. Flying from Oryol, Leie claimed a Mikoyan-Gurevich MiG-3 fighter shot down on 2 February, his first aerial victory on the Eastern Front.