The standard's standard
U.S. Air Force Senior Airman Evan Caso, 31st Maintenance Squadron precision measurement equipment laboratory journeyman, checks the setscrew height on a rate sensor unit boresight, Feb. 10, 2015, at Aviano Air Base, Italy. The PMEL Airmen support 5,200 different types of equipment on base for 84 different work centers. (U.S. Air Force photo by Airman 1st Class Ryan Conroy/Released)