Senior Master Sgt. Todd Wylie, 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. Wylie has been with the squadron for eight years. (U.S. Air Force photo by Jamal D. Sutter)

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 check was part of the functional test stage of the aircraft’s programmed depot maintenance, a process designed to ensure aircraft are safe and mission ready. (U.S. Air Force photo by Jamal D. Sutter)

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 is responsible for conducting flight tests on F-15s, C-130s and C-5s once programmed depot maintenance is completed. (U.S. Air Force photo by Jamal D. Sutter)

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 check was part of the functional test stage of the aircraft’s programmed depot maintenance, a process designed to ensure aircraft are safe and mission ready. (U.S. Air Force photo by Jamal D. Sutter)

Senior Master Sgt. Todd Wylie, 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 C-5 is assigned to the 436th Airlift Wing out of Dover Air Force Base, Del. (U.S. Air Force photo by Jamal D. Sutter)

Master Sgt. Richard Titcomb, 339th Flight Test Squadron C-5 flight engineer, readjusts his glasses while performing pre-flight checks to a C-5M Super Galaxy March 29, 2017, at Robins Air Force Base, Ga. Titcomb has been with the squadron for nearly two years. (U.S. Air Force photo by Jamal D. Sutter)

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)

A C-5M Super Galaxy assigned to the 436th Airlift Wing out of Dover Air Force Base, Del., sits on the flightline March 29, 2017, at Robins Air Force Base, Ga. The aircraft was at Robins undergoing programmed depot maintenance, a process designed to ensure aircraft are safe and mission ready. (U.S. Air Force photo by Jamal D. Sutter)