Fuel cell
Staff Sgt. Jonathan Phillips, 141st Maintenance Squadron fuel cell technician, looks on as Airman 1st Class Sarah Deberardinis, 141st MXS fuel cell technician, checks technical data prior to starting a repair on a KC-135 Stratotanker fuel cell at Fairchild Air Force Base, Wash. Without fuel systems specialists, the KC-135 would never get off the ground and could not deliver fuel to other aircraft, making fuels systems specialists the backbone of how the Air Force fuels the fight. (U.S. Air Force photo/Tech. Sgt. Michael Lee Brown)