On 25 April 1945, Mutke landed at Dübendorf, Switzerland, flying the Me 262A-1a jet fighter, 'White 3', from 9. "Staffel", "Jagdgeschwader" 7. He claimed that he got lost during a combat mission and landed there by mistake, although there were suspicions that he'd defected. The Swiss authorities never attempted to fly the plane, keeping it in storage and returning it to Germany on 30 August 1957. He sued the post-war German government, unsuccessfully, for the return of the plane, claiming it was his own property.