The year 1991 also saw the last major change to the enlisted rank insignia. In October 1991 General McPeak and Chief Master Sergeant of the Air Force Pfingston announced that the senior NCO tier would have new chevron layouts and that all chevrons would have a white star in the center. The change in senior NCO chevrons was the first since chevrons came into being in 1948. Until that time, Master Sergeant had been composed of six inverted chevrons (six down) with none pointing up, Senior Master Sergeant six down with one up and Chief Master Sergeant six down with two up. The new layout changed the insignia to the current layout (see chart above). The second change, changing the star color to white, was actually two changes in one. It added a star to the Airman through Senior Airman rank insignias where there had been none since 1975 (the blue star carried by these chevrons was the same color as the blue in the stripes giving the impression that the star was not there) and changing the silver star on the NCO and senior NCO chevrons to white.
when did air force master sergeant stripes change
1991 1991