<Dl> <Dd> 1: The U.S. Air Force does not have a separate First Sergeant rank; it is instead a duty position denoted by a diamond within the upper field of the E-7 / MSgt, E-8 / SMSgt, E-9 / CMSgt paygrades / chevrons / ranks and is abbreviated "1st Sgt ." </Dd> </Dl> <Dd> 1: The U.S. Air Force does not have a separate First Sergeant rank; it is instead a duty position denoted by a diamond within the upper field of the E-7 / MSgt, E-8 / SMSgt, E-9 / CMSgt paygrades / chevrons / ranks and is abbreviated "1st Sgt ." </Dd> <P> While all Air Force military personnel are referred to as Airmen, it can specifically refer to the pay grades of E-1 through E-4 which are below the level of non-commissioned officers (NCOs). Above the pay grade of E-4 (E-5 through E-9) all ranks fall into the category of NCO and are further subdivided into NCOs (E-5 & E-6) and Senior NCOs (E-7 through E-9); the term Junior NCO is sometimes used to refer to staff sergeants and technical sergeants (E-5 & E-6). </P> <P> The Air Force is the only one of the five branches of the United States military where NCO status is now only achieved at the grade of E-5 . Formally, the grade of Sergeant was obtained after a time as a Senior Airman and successful completion of the Air Force NCO School . In all other branches NCO status can be achieved at the grade of E-4 (a Corporal in the Army and Marine Corps, Petty Officer Third Class in the Navy and Coast Guard). However, E-4s in the Army with the rank of Specialist are not NCOs . The Air Force mirrored the Army from 1976 to 2 May 1991 with an E-4 being either a Senior Airman wearing three stripes without a star or a Sergeant (informally referred to as "Buck Sergeant") which was noted by the presence of the central star and considered an NCO . Despite not being an NCO, a Senior Airman who has completed Airman Leadership School can be a supervisor . </P>

What rank is an e9 in the air force
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