Air supply
Staff Sgt. Leirin Andra, 931st Operation Support Squadron air crew flight equipment, assists Master Sgt. Warren Bearup, 931st OSS boom operator, with a helmet functionality check Aug. 21st, 2013, at McConnell Air Force Base Kan. AFE Airmen must make sure all equipment aircrews may use is in working condition and able to operate at varying altitudes. (U.S. Air Force photo/Airman 1st Class John Linzmeier)