Tech. Sgt. Caleb Warren, an aerospace ground equipment craftsman assigned to the 28th Maintenance Squadron, holds up a Consolidated Aircraft Support System air valve at Ellsworth Air Force Base, S.D., March 16, 2017. Over the course of the last 10 years the 28th Civil Engineer Squadron and 28th MXS have put more than $500,000 worth of modifications into CASS in order to keep it running. (U.S. Air Force photo by Airman 1st Class Donald C. Knechtel)