Schentke was born on 23 November 1919 in Kriescht in the Province of Brandenburg within the Weimar Republic, present-day Krzeszyce in western Poland.

Gruppe of JG 3 was considered operationally ready and transferred to Detmold Airfield where it was tasked with defending Germany's western border during the "Phoney War".

On this mission, Schentke claimed a Royal Air Force (RAF) Supermarine Spitfire fighter shot down.

Gruppe spent a couple of days of R&R skiing in the Kleinwalsertal before returning for active service on 17 March.

These air elements supported Generalfeldmarschall Gerd von Rundstedt's Heeresgruppe Süd (Army Group South), with the objective of capturing Ukraine and its capital Kiev.

Then, continuing eastward over the steppes of southern USSR to the Volga with the aim of controlling the oil-rich Caucasus[11] Schentke claimed his first aerial victory on the Eastern Front on 24 June when he shot down a Soviet Polikarpov I-15 biplane fighter aircraft.

[12][Note 2] Over the next weeks, Schentke frequently flew as wingman to Hauptmann Walter Oesau, who was the Gruppenkommandeur (group commander) of III.

[19] In late July 1942, after 71 aerial victories claimed, Schentke was transferred to Ergänzungsgruppe Süd (Supplementary Fighter Group South) as an instructor, promoted to Leutnant (second lieutenant) and awarded the German Cross in Gold (Deutsches Kreuz in Gold) on 24 September.

Gruppe of JG 3, was responsible for providing fighter escort to Junkers Ju 52 transport aircraft and Heinkel He 111 bombers shuttling supplies for the encircled German forces fighting in the Battle of Stalingrad.

[21] On 25 December 1942, Schentke claimed an Ilyushin Il-2 ground-attack aircraft and was then was shot down in aerial combat with Soviet bombers near the Kotluban train station.

[22] Although he was seen to bail out of his Bf 109 G-2 (Werknummer 13885—factory number) behind enemy lines, Schentke remains missing in action.

[14] According to Spick, Schentke was credited with 87 aerial victories, including four during the Battle of France and Britain and further 83 on the Eastern Front, claimed in an unknown number of combat missions.