Air crewmen prepare to load a training mannequin onto an MH-60S Sea Hawk helicopter assigned to the Blackjacks of Helicopter Sea Combat Squadron 21 during a training exercise at Naval Medical Center San Diego. HSC-21 is based at Naval Air Station North Island and is preparing for an upcoming search and rescue qualification. The medical center receives an average of 50 medical evacuations per month. (Photo by Seaman Clay M. Whaley)