Hagerstown Airport, Maryland

This small municipal airport was once a major military aircraft production site, known as Air Force Plant 11. It was the site of a Fairchild Aircraft factory, making training and transport planes during World War Two, and military transport planes after the war. It also was a manufacturing site for A-10 Thunderbolts, known as Warthogs and “tank killers,” until the 1980s. Over the years thousands of planes were built there. The largest remaining structure is an 800,000 square foot aircraft assembly building, used for other things now. The Sierra Nevada Corporation, a military and aerospace company, also has facilities at the airport.