Wenzl flew first for an artillery cooperation unit, FAA 236. He transferred, first to KEK Ost, then to Jasta 31 in the spring of 1917. For his first victory, he shot down a Spad on 19 April 1917. He had an unconfirmed claim the following month. He would not score again for a year, after he had switched into Jasta 11 on 27 March 1918. After his second victory, on 16 May, he transferred to Jasta 6 the next day. He began a five-month scoring streak on 5 June, running his total to twelve on 5 November 1918. Wenzl also served as the squadron's acting commander from 10 August to 9 September 1918.
Above the Lines: The Aces and Fighter Units of the German Air Service, Naval Air Service and Flanders Marine Corps 1914 - 1918 Norman L. R. Franks, et al. Grub Street, 1993. ISBN 0-948817-73-9, ISBN 978-0-948817-73-1.