Task: Question Generation
Input (English): Context : Willy Lehnert (9 March 1916 -- 10 July 1975) was a German Luftwaffe bomber radio operator and recipient of the Knight's Cross of the Iron Cross (German: Ritterkreuz des Eisernen Kreuzes) during World War II. The Knight's Cross of the Iron Cross was awarded to recognise extreme battlefield bravery or successful military leadership. 
Subject : Willy Lehnert 
Relation : military branch
Output (English): Which armed forces utilised the service of Willy Lehnert?