Hauptsturmführer was a Nazi Party paramilitary rank that was used in several Nazi organizations such as the SS, NSKK and the NSFK. The rank of Hauptsturmführer was a mid-level commander and had equivalent seniority to a captain (Hauptmann) in the German Army and also the equivalency of captain in foreign armies.
Hauptsturmführer Albert Klett, photographed in 1945
National Socialist Flyers Corps
The National Socialist Flyers Corps was a paramilitary aviation organization of the Nazi Party.
NSFK Standarte
Image: Organisationsbuc 00nati 0 orig 0711 ORGANISATIONSBUCH DER NSDAP 1943 Tafel 70 Das Nationalsozialistische Fliegerkorps NSFK. Standarte Sturmfahne Public domain CROPPED
Image: Organisationsbuc 00nati 0 orig 0712 ORGANISATIONSBUCH DER NSDAP 1943 Tafel 71 Das Nationalsozialistische Fliegerkorps NSFK. Rottenführer im grosse Dienstanzug, Standartenführer im kleinen Dienstanzug Public domain CROPPED
Image: Organisationsbuc 00nati 0 orig 0713 ORGANISATIONSBUCH DER NSDAP 1943 Tafel 72 Das Nationalsozialistische Fliegerkorps NSFK. Standartenführer im Ausgehanzug, Sturmbannführer im Abendanzug Public domain CROPPED