Master Sgt. Richard Titcomb, 339th Flight Test Squadron C-5 flight engineer, performs pre-flight checks to a C-5M Super Galaxy March 29, 2017, at Robins Air Force Base, Ga. The 339th FLTS is part of the 413th Flight Test Group and certifies aircraft as worthy to return to service after programmed depot maintenance is completed. (U.S. Air Force photo by Jamal D. Sutter)