During World War II, he was credited with 64 aerial victories in Defense of the Reich all of which claimed at night and includes the destruction of 57 four-engined bombers.

In parallel, he was accepted for flight training with the Deutsche Verkehrsfliegerschule, a covert military-training organization, and at the Lipetsk fighter-pilot school.

Following flight training, he served with Jagdgeschwader 134 "Horst Wessel" (JG 134—134th Fighter Wing) and volunteered to fight in the Spanish Civil War where he claimed one aerial victory.

At the outbreak of World War II on 1 September 1939, Radusch served with Zerstörergeschwader 1 and was appointed a squadron leader in June 1940.

In February 1944, Radusch was given command of Nachtjagdgeschwader 2 and received the Oak Leaves to his Knight's Cross on 6 April 1944 after 58 nocturnal aerial victories.

Radusch, the son of a middle school director, was born on 11 November 1912 in Schwetz, present-day Świecie in northern Poland, at the time in West Prussia within the German Empire.

Staffel (2nd squadron) of Jagdgruppe 88 they each claimed one Polikarpov I-15 shot down, one of which was flown by Felipe del Río Crespo, a seven victory flying ace.

[10] In 1939, Radusch served on the staff of the Inspekteur der Jagdflieger, an organization within the Luftwaffe responsible for the readiness, training and tactics of the fighter force.

On the night of 30 April and 1 May, 50 Royal Air Force (RAF) Armstrong Whitworth Whitley, Vickers Wellington and Handley Page Hampden bombers attacked Luftwaffe airfields in Norway.

Radusch, Falck, Oberleutnant Werner Streib, and another pilot, followed the bombers shortly before sunup on their flight back to England.

[1] On 22 June 1940, General der Flieger Albert Kesselring called Falck that Hermann Göring, commander-in-chief of the Luftwaffe, had tasked him with the creation of Nachtjagdgeschwader 1 (NJG 1—1st Night Fighter Wing).

[13] Following the 1939 aerial Battle of the Heligoland Bight, bombing missions by the RAF shifted to the cover of darkness, initiating the Defence of the Reich campaign.

[17] Radusch claimed his first nocturnal aerial victory on 10 April 1941 when he shot down a Wellington bomber 2 kilometres (1.2 miles) southwest Papenburg.

[19] On the night of 17/18 August, Bomber Command launched Operation Hydra, the attack on a German scientific research centre at Peenemünde.

[22] On 21 January, Major Heinrich Prinz zu Sayn-Wittgenstein, the commander of Nachtjagdgeschwader 2 (NJG 2—2nd Night Fighter Wing), had been killed in action.

[26] Also present at the ceremony were Anton Hafner, Otto Kittel, Günther Schack, Emil Lang, Alfred Grislawski, Erich Rudorffer, Martin Möbus, Wilhelm Herget, Hans-Karl Stepp, Rudolf Schoenert, Otto Pollmann and Fritz Breithaupt, who all received the Oak Leaves on this date.

[30] On 1 September 1958, Radusch reentered military service in the Bundeswehr holding the rank of Oberst in the West German Air Force.