Anoberekwa muAustria muna 1918 uye achishanda somubiki kusvika makore ake okupedzisira okuyaruka Bartels akabatana ne"Luftwaffe" pashure pokubatanidzwa kweGermany neAustria muna 1938. Bartels akapedza kudzidziswa kwake kuva mutyairi wendege muna 1941. Akapiwa kuna "Jagdgeschwader" 26 "Schlageter" (JG 26<unk>26th Fighter Wing) pamusoro Channel Front
iro rakanga rine basa rokubata kupindira kweRoyal Air Force (RAF) pamusoro peFrance neBelgium. Akawana kukunda kwake kwokutanga mumhepo muna August 1941. Bartels akaendeswa ku "Jagdgeschwader" 5 (JG 5<unk>5th Fighter Wing) kuEastern Front kwaakapihwa Knight's Cross yeIron Cross yekukunda kwe46 mumhepo. Muna 1943 Bartels akaendeswa ku "Jagdgeschwader" 27 "Afrika" (JG 27<unk>27th Fighter Wing) kunoshanda muMediterranean neBalkan theaters uye pakupera kwegore aive nekukunda makumi manomwe nenomwe. Muna 1944 akadzokera kuWestern Front ndokurwa muNormandy Campaign muna June kusvika August 1944. Nhamba yaBartel pachake yakakwira kusvika ku96 uye akasarudzwa nokuda kweOak Leaves of the Knight's Cross.