Oberstabsfeldwebel

Oberstabsfeldwebel (OStFw or OSF, lit. 'Senior staff field usher') is the highest Non-commissioned officer (NCO) rank in German Army and German Air Force. It is grouped as OR-9 in NATO, equivalent to a sergeant major in the United States Army and a Warrant Officer Class 1 in the British Army. Attainment of this rank requires at least sixteen years since promotion to feldwebel and at least six years since promotion to hauptfeldwebel

In army/ air force context NCOs of this rank were formally addressed as Herr Oberstabsfeldwebel also informally / short Oberstaber.

The rank was introduced in the German Heer equivalent to the Marine grade Oberstabsbootsmann in 1955, and belongs to the grad group Unteroffiziere mit Portepee.

History
The rank is a comparatively new rank, and had not been used by any German military prior to in 1955. The Kriegsmarine, did however have a Stabsoberfeldwebel, used from 1939 to 1945.

Rank sequence
The sequence of ranks (top-down approach) in that particular group (Senior NCOs with portepee) is as follows:
 * OR-9: Oberstabsfeldwebel / Oberstabsbootsmann
 * OR-8: Stabsfeldwebel / Stabsbootsmann
 * OR-7: Hauptfeldwebel / Hauptbootsmann
 * OR-6a: Oberfeldwebel / Oberbootsmann
 * OR-6b: Feldwebel / Bootsmann