Senior Airman David Moralina, 1st Expeditionary Civil Engineer Group water and fuel systems management technician, fastens the inner layer of a small shelter system at Prince Sultan Air Base, Saudi Arabia on Oct. 31, 2019. The significant infrastructure improvements made by civil engineering Airmen at PSAB enable U.S. Air Forces Central Command and U.S. Central Command to assure and enhance the defense of Saudi Arabia and security of the Middle East region. (U.S. Air Force Photo by Tech. Sgt. John Wilkes)