Kuban bridgehead and Kursk

The Gruppe was moved to the combat area of the Kuban bridgehead on 1 April 1943 where it was based at an airfield at Taman. Operating from Taman until 2 July, III. Gruppe also flew missions from Kerch on 12 May, from Sarabuz and Saky on 14 May, Zürichtal, present-day Solote Pole, a village near the urban settlement Kirovske on 23 May, and Yevpatoria on 25/26 June.^[12] Korts became an "ace-in-a-day" for the first time on 26 May, claiming four Petlyakov Pe-2 bombers and a Soviet-flown Supermarine Spitfire fighter shot down.^[13] The following day, he again claimed five aerial victories, making him an "ace-in-a-day" for the second time.^[14]

In preparation for Operation Citadel, III. Gruppe was relocated to the central sector of the eastern Front. The Gruppe first moved to Zaporizhzhia and then to Ugrim on 3 July. There, under the command of Luftflotte 4, they supported Army Group South fighting on the southern flank of the salient.^[15] On 5 July, the first day of the Battle of Kursk, Hauptmann Günther Rall replaced von Bonin as Gruppenkommandeur (group commander) of III. Gruppe.^[16] That day, Korts claimed three LaGG-3 fighters and an Ilyushin Il-2 ground-attack aircraft.^[17] This includes a claim over a Soviet fighter shot down near Oboyan.^[18] A week later, Korts was awarded the German Cross in Gold (Deutsches Kreuz in Gold) on 12 July 1943.^[3] That day, Soviet forces launched Operation Kutuzov and advanced towards Orel from the north and east. Two days later, III. Gruppe was ordered to an airfield at Sowjetzki just north of Orel near the Oka river. There, Korts claimed four aerial victories, one on 16 July, two on 17 July, and one 18 July.^[19] On 20 July, the Gruppe moved to Ivanovka near Bryansk where it was subordinated to Jagdgeschwader 54 (JG 54—54th Fighter Wing).^[20]

Squadron leader and missing in action

Promoted to an officer's rank, Korts was appointed Staffelkapitän (squadron leader) of 9. Staffel (9th squadron), also referred to as the Karaya-Staffel of JG 52, on 27 July 1943. He replaced Oberleutnant Rudolf Trepte who had temporarily led the Staffel after Hauptmann Ernst Ehrenberg had been killed in action on 10 May.^[16][21] At the time, III. Gruppe was based at Ivanovka near Bryansk and engaged in the fighting near Orel during Operation Kutuzov. On 28 July, the Bryansk Front, supported by ground attack aircraft, attacked the German forces at Oryol.^[22] During the course of the day, Korts claimed a LaGG-3 fighter shot down west of Bolkhov. The following day, he claimed another LaGG-3 fighter destroyed.^[23] On 2 August, III. Gruppe moved to an airfield at Warwarowka, located south of Belgorod, where they stayed for three days.^[24] There, Korts claimed a total of fifteen aerial victories, including his 75th aerial victory on 3 August.^[25] On 4 August, strong Soviet forces breached the right defensive flank of the 4th Panzer Army. In defense of this attack, III. Gruppe was engaged in combat near Tomarovka, northwest of Belgorod.^[25] In total, the Gruppe claimed 42 aerial victories that day, including nine of which by Korts. This made him an "ace-in-a-day" for the third time.^[26]

On 5 August, the Gruppe moved to an airfield at Kharkov-Rogan airfield, southeast of Kharkov.^[27] Flying from this airfield, Korts claimed five aerial victories until III. Gruppe was ordered to Kharkov-Waitschenko, southeast of Kharkov-Rogan, on 11 August.^[28] He claimed two LaGG-3 fighters shot down on 14 August, the day the Gruppe relocated to Pereshchepyne.^[29] Flying from Pereshchepyne, Korts reached the century mark on 17 August 1943 when he shot down two LaGG-3 fighters in the vicinity of Izium.^[30] He was the 50th Luftwaffe pilot to achieve the century mark.^[31] The following day, he claimed another LaGG-3 fighter before the Gruppe moved to Mikhaylovka.^[32] On 19 August, Korts became an "ace-in-a-day" for the fourth time, claiming three LaGG-3 fighters and two Il-2 ground-attack aircraft destroyed.^[33] On 23 August, III. Gruppe was ordered to an airfield at Makeyevka while Korts and his wingman Unteroffizier Hans-Otto Müller were sent to Kramatorsk for two days to liaise with a Romanian fighter unit there.^[34]

Korts and his unit received the announcement that he had been awarded the Knight's Cross of the Iron Cross (Ritterkreuz des Eisernen Kreuzes) on 29 August, the day he went missing in action.^[35][36][37] Flying Messerschmitt Bf 109 G-6 (Werknummer 15899—factory number), he and his wingman Müller in Bf 109 G-6 (Werknummer 15869) were last seen in combat with Soviet P-39 Airacobra fighters in the vicinity of Amvrosiivka.^[38] He was succeeded by Erich Hartmann as Staffelkapitän of 9. Staffel.^[35][39][40]

Aerial victory claims

According to US historian David T. Zabecki, Korts was credited with 113 aerial victories.^[41] Authors Obermaier and Spick also list Korts with 113 aerial victories.^[1][42] Mathews and Foreman, authors of Luftwaffe Aces — Biographies and Victory Claims, researched the German Federal Archives and found records for 108 aerial victory claims, all of which claimed on the Eastern Front.^[43] The authors Prien, Stemmer, Rodeike and Bock indicate that additional five aerial victories have been claimed by Korts, two of which end of June or early July 1943, and further three on 5 August 1943.^[44]

Victory claims were logged to a map-reference (PQ = Planquadrat), for example "PQ 0516". The Luftwaffe grid map (Jägermeldenetz) covered all of Europe, western Russia and North Africa and was composed of rectangles measuring 15 minutes of latitude by 30 minutes of longitude, an area of about 360 square miles (930 km²). These sectors were then subdivided into 36 smaller units to give a location area 3 km × 4 km (1.9 mi × 2.5 mi) in size.^[45]

Awards

• Iron Cross (1939) 2nd and 1st Class^[67]
• Honor Goblet of the Luftwaffe on 1 February 1943 as Feldwebel and pilot^[68]
• German Cross in Gold on 12 July 1943 as Leutnant in the Stab III./Jagdgeschwader 52^{[69][Note 9]}
• Knight's Cross of the Iron Cross on 29 August 1943 as Leutnant and pilot in the 9./Jagdgeschwader 52^[70][71]