U.S. Air Force Senior Airman Ruben Mejia, 1st Maintenance Squadron precision measurement equipment laboratory journeyman, calibrates parallel bars at Langley Air Force Base, Va., Aug. 18, 2015. The PMEL flight consists of approximately 25 personnel who calibrate and repair measurement tools used across the installation. (U.S. Air Force photo by Senior Airman Kayla Newman/Released)

U.S. Air Force Senior Airman Ruben Mejia, 1st Maintenance Squadron precision measurement equipment laboratory journeyman, calibrates parallel bars at Langley Air Force Base, Va., Aug. 18, 2015. Langley PMEL specialists are responsible for the accuracy and tolerance of electronic and physical dimensional test equipment across the installation. (U.S. Air Force photo by Senior Airman Kayla Newman/Released))

U.S. Air Force Senior Airman Samuel Weirick, 1st Maintenance Squadron precision measurement equipment laboratory journeyman, calibrates a signal generator at Langley Air Force Base, Va., Aug. 18, 2015. The PMEL specialists are responsible for calibrating equipment used for measuring in practically every aspect of maintenance. (U.S. Air Force photo by Senior Airman Kayla Newman/Released)

An obsolete inches-of-water-gauge calibrator is updated with a digital standard at Langley Air Force Base, Va., Aug. 18, 2015. The unit can generate one to 24 inches of water pressure in order to get accurate readings on water levels. (U.S. Air Force photo by Senior Airman Kayla Newman/Released)

A U.S. Air Force Senior Airman Ruben Mejia, 1st Maintenance Squadron precision measurement equipment laboratory journeyman, calibrates parallel bars at Langley Air Force Base, Va., Aug. 18, 2015. Langley PMEL specialists at Langley service approximately 119 customers, to include Air Combat Command and the U.S. Coast Guard. (U.S. Air Force photo by Senior Airman Kayla Newman/Released)