Voss transferred to the Luftstreitkräfte (German Air Service) on 1 August 1915, joining Fliegerersatz-Abteilung 7 (Training Detachment 7) in Cologne. On 1 September, he began learning to fly at Egelsberg airfield in his hometown of Krefeld. A gifted natural pilot, Voss flew his first solo flight on 28 September. He was retained as an instructor at the training school after he graduated on 12 February 1916. On 2 March, as part of his progress towards becoming an officer, he was promoted to Vizefeldwebel (a senior noncommissioned officer).Franks et al. 1993, pp. 223–225. He was the youngest flight instructor in German service.Crean 2011, p. 40.
