Airman Calvin Daniels, 28th Maintenance Squadron aircrew egress system apprentice, installs a safety pin into an Advance Concept Ejection Seat during a training session at Ellsworth Air Force Base, S.D., Jan. 23, 2012. Safety pins are installed into ejector seats to prevent accidental ejections by air and ground crews during maintenance operations. (U.S. Air Force photo by Airman 1st Class Zachary Hada/Released)