Tech. Sgt. Abimael Santiago-Soto, 9th Airlift Squadron noncommissioned officer in charge of training, explains checklists while instructing flight engineer students aboard a Dover Air Force Base C-5M Super Galaxy during a Major Command Service Tail Trainer at Holloman AFB, New Mexico, June 2, 2021. The 9th AS performs MSTTs to expedite upgrade and qualification training for C-5M loadmasters and flight engineers. (U.S. Air Force photo by Senior Airman Faith Schaefer)