OSAN AIR BASE, Republic of Korea -- The 51st Civil Engineer Squadron hosts an ability to survive and operate training at Osan Air Base, Republic of Korea, July 24, 2025. The ATSO training involved realistic training demonstrations from Airmen assigned to the 51st CES, 51st Security Forces Squadron, and the 51st Communications Squadron, where 113 Airmen trained and learned pre-attack actions, and how to operate in a contingency environment.