David Spangler, 633d Civil Engineer Squadron electrical foreman, locks up a power box at Joint Base Langley-Eustis, Virginia, March 12, 2025. JBLE conducted the Energy Resilience Readiness Exercise to identify any hidden vulnerabilities and verify that backup systems and processes function as expected with no mission impacts. (U.S. Air Force photo by Airman 1st Class Donnell Ramsey)