The United States Air Force has designated its E-7 Noncommissioned Officers (NCOS) as Master Sergeants ever since it came into existence, but the design of the insignia has undergone a couple tweaks in the seven decades since then. Initially, the Air Force simply used the same titles and insignia design as the Army did for its enlisted ranks: In the case of Master Sergeants, this was three upward-pointing chevrons and three “rockers” at the bottom. But the Air Force radically changed the design in 1948, when the upper chevrons were reversed to point downward, made slightly curved, and had an Air Force star in a circle superimposed over them.
With the introduction of E-8 and E-9 pay grades in 1958 and the need for insignias to represent them, the Air Force took what could be considered the easy route and simply added the old, upward-point Army chevrons above the “gull-winged” chevrons already on the E-7 insignia—but the Master Sergeant insignia remained unchanged.
More E-7 Master Sergeant Insignia and DevicesIt wasn’t until 1991 that the current insignia was established by changing the chevron system used for E-7 through E-9 by moving one stripe (a rocker) from the bottom and adding it at the top as an upward-pointing chevron. With the change, all Senior Noncommissioned Officer (SNCOs) would have an insignia with an upward-pointing chevron(s), immediately distinguishing them from the two ranks (E-5 and E-6) that the Air Force classified as the “NCO Tier.”