Senior airman Senior airman ( SrA ) is the fourth enlisted rank in the United States Air Force , just above airman first class and below staff sergeant . It has a pay grade of E - 4 . Between its approval on 30 December 1975 ( with implementation 1 June 1976 ) and 19 March 1991 , senior airmen wore sleeve chevrons with blue center stars instead of silver to distinguish them from the non - commissioned officer rank of " sergeant " , also a pay grade of E - 4 . The latter was abolished in 1991 and the blue center star was changed to white to conform to all enlisted rank chevrons . The Air Force promotes an airman first class ( A1C ) to senior airman after 36 months time in service ( TIS ) and 20 months time in grade ( TIG ) , or 28 months TIG , whichever occurs first . Outstanding airmen first class , limited to no more than 15 percent of the total , may be promoted to senior airmen six months early , in a competitive process called Below - the - Zone , which normally involves going before a competitive board . Senior airmen are expected to be technically proficient and begin to develop leadership skills , and may be expected to supervise an airman of lesser rank . Senior airmen must attend the six - week Airman Leadership School , the first course of the Air Force ' s College of enlisted professional military education , before being promoted to staff sergeant . History . Formerly , from 1976 to 1991 , this grade was divided into ranks with separate titles : sergeant ( referred to unofficially but almost universally within the USAF as " buck sergeant " or simply " buck " ) , a non - commissioned officer ; and senior airman , which is the equivalent of specialist , a non - supervisory rank . Senior airmen were promoted to sergeant after 12 months ' time in grade and completion of the now - defunct non - commissioned officer preparatory course . This schism reflected a desire by the Air Force in 1976 to subdivide enlisted ranks into a three - tier organization , a move which was resisted by the Chief Master Sergeant of the Air Force , resulting in the compromise dual - rank that lasted fifteen years . The last Air Force promotions to sergeant were effective 1 May 1991 . Those personnel who had been promoted to sergeant prior to this cut off date retained the rank until being promoted to a higher rank or leaving the service . There are no longer any personnel on active duty who hold this rank . Due to high year of tenure rules in effect at the time , the last person to hold the rank was forced out of the Air Force on 23 March 1998 . Sergeants wore the same chevrons as present - day senior airmen . Senior airmen wore similar chevrons , but with a blue ( green on the fatigue or battle dress uniform ) subdued central star , as did all airmen in the lowest tier . As with any change in policy , many airmen supported this change , while others protested . The grades of senior airman and sergeant held the same pay grade , but sergeants were expected to supervise other airmen as part of their duties as non - commissioned officers . Those Air Force members against the change protested that the rank of sergeant prepared airmen for transition to staff sergeant , and that new staff sergeants would therefore be less well - trained for their new position . Air Force personnel who supported the change argued that proper leadership training eliminated the need for a separate rank within the pay grade ; moreover , the rank created disparity between individuals earning the same pay and benefits and , often , performing the same duties , since often there were no additional junior airmen in a given duty section for a new buck sergeant to supervise . Today , senior airmen who complete Airman Leadership School may supervise lower - ranking airmen but are not considered non - commissioned officers . Senior airmen are the lowest USAF rank eligible for selection as a USAF recruiter , and as a military training instructor for USAF basic military training . Today , the USAF is again the only United States military service that does not have an non - commissioned officer rank at the E - 4 pay grade . Previously , from 1947 to 1952 , and from 1967 to 1997 , the rank of sergeant was an NCO rank in the USAF . In the interim , from 1952 to 1967 , the paygrade rank was titled Airman First Class .