Airmen assigned to the 1st Maintenance Squadron precision measurement equipment laboratory use gauge blocks to calibrate linear measurement tools at Joint Base Langley-Eustis, Va., March 17, 2017. The PMEL flight supports 98 agencies to include the Fitness Assessment Cell, the 633rd Medical Group, the 1st Maintenance Group, the U.S. Coast Guard, U.S. Army, U.S. Air National Guard and other Air Force bases across the country. (U.S. Air Force photo/Senior Airman Areca T. Bell)