Following flight training, he was posted to Jagdgeschwader 54 (JG 54—54th Fighter Wing) in 1941, operating on the Eastern Front.

In March 1943, Rademacher joined Schwarm, flight of four aircraft, headed by Walter Nowotny, the most successful fighter pilot team in the Luftwaffe.

Staffel was temporarily commanded by Oberleutnant Max-Hellmuth Ostermann and subordinated to I. Gruppe (1st group) headed by Hauptmann Erich von Selle.

[5] That day, the Gruppe flew missions in the area of the Volkhov, southeast of Leningrad, and to Tosno where Rademacher claimed an Ilyushin Il-2 ground attack aircraft shot down.

Initially reported as missing in action, he was replaced by Hauptmann Hans Philipp as commander of I. Gruppe on 17 February.

[13] In early July, I. Gruppe of JG 54 was ordered to move to Oryol, in the southern sector of Army Group Centre, where it fought in Operation Citadel which initiated the Battle of Kursk.

That day, I. Gruppe claimed 59 aerial victories, including seven by Rademacher in the vicinity of Maloarkhangelsk and Kursk, making him an "ace-in-a-day".

Staffel of Jagdgruppe Nord, a fighter pilot training unit later renamed to Ergänzungs-Jagdgeschwader 1 where he served as an instructor.

[1][12] The presentation was made at the Luftwaffe airfield in Sagan-Küpper, present-day Nowa Kopernia in Żagań County, during his convalescence by Oberst Hannes Trautloft, a former Geschwaderkommodore (wing commander) of JG 54 at the time serving with the staff of the General der Jagdflieger (General of Fighters).

[22] Depending on source, Rademacher claimed between eight and sixteen aerial victories flying the Messerschmitt Me 262 first operational jet fighter, making him one of the top jet-aces of the war.

The USAAF lost 23 Boeing B-17 Flying Fortress bombers and seven North American P-51 Mustang fighters in the attack.

[26] On 9 February, over 1,200 heavy bombers of the Eighth Air Force attacked synthetic fuel factories, railroad and other targets.

[30] On 18 March, the Eighth Air Force headed for various railway stations and tank factories in the greater Berlin area with 1,329 heavy bombers, escorted by 632 fighter aircraft.

[31] The next day, 1,273 heavy bombers from the USAAF 3rd Air Division attacked the synthetic fuel factories.

[32] On 24 March, the Eighth Air Force flew over 1,700 combat missions in support of Operation Plunder, the crossing of the Rhine.

That day, approximately 250 heavy bombers also headed for Berlin to bomb the tank factories close by.

[33] The Eighth Air Force attacked fuel storage sites in areas of Braunschweig, Hamburg and Lauenburg on 25 March.

[34] On 31 March, 428 Avro Lancaster and Handley Page Halifax bombers of the Royal Air Force (RAF) No.

[35] In the afternoon, the Eighth Air Force lost a few aircraft to Me 262 fighters in combat over Zeitz, Brandenburg and Braunschweig.

[36] On 4 April, the USAAF Eighth Air Force dispatched 1,431 heavy bombers, escorted by 850 fighter aircraft, to northern Germany.

[1] According to Spick however, Rademacher is credited with 126 aerial victories, 90 of which claimed over the Eastern Front and 36 in the western theatre of operations, including 10 heavy bombers.