LANGLEY AIR FORCE BASE, Va. -- Staff Sgt. Jennifer Flecker, 1st Aerospace Medicine Squadron aerospace physiology logistics noncommissioned officer in charge (left), performs a gas mask fit test on Tech. Sgt. Eugene McCardell, 1st Maintenance Group Air Force repair enhancement program manager, March 14. The gas mask fit test is a requirement for all Airmen participating in the upcoming operational readiness exercise March 17 through 22. These tests ensure masks fit properly and no hazardous chemicals can reach an Airman’s respiratory system. (U.S. Air Force photo/Airman 1st Class Chase Skylar DeMayo)