Narrator: The 309th AMARG stores the world's largest collection of military aircraft here in the Arizona desert. Col. Jennifer Barnard: I like to call this the ugliest plane out here, the YC-14. It was an aircraft that never went into production. Narrator: Eight hundred mechanics work nonstop, reclaiming critical old parts and regenerating aircraft so they can go back into service. Barnard: I can't just pull over an airplane like you can a car. And we have to make sure that these aircraft are safe to fly. Our goal is not to be like a cemetery for the aircraft. Narrator: That's Col. Barnard. She's served 25 years as a US Air Force Aircraft Maintenance Officer.