Question: The Champaign Aviation Museum is an aviation museum in Urbana, Ohio, in which country, the museum and its volunteers are restoring a B-17 Flying Fortress back to flying status, a our-engine heavy bomber developed in the 1930s for the United States Army Air Corps (USAAC)?
Related documents: [0]  [DOC] The Champaign Aviation Museum is an aviation museum in Urbana, Ohio, United States. The museum and its volunteers are restoring a B-17 Flying Fortress back to flying status. [END] 
[1]  [DOC] The Boeing B-17 Flying Fortress is a four-engine heavy bomber developed in the 1930s for the United States Army Air Corps (USAAC). Competing against Douglas and Martin for a contract to build 200 bombers, the Boeing entry (prototype Model 299/XB-17) outperformed both competitors and exceeded the air corps' performance specifications. Although Boeing lost the contract (to the Douglas B-18 Bolo) because the prototype crashed, the air corps ordered 13 more B-17s for further evaluation. From its introduction in 1938, the B-17 Flying Fortress evolved through numerous design advances, becoming the third-most produced bomber of all time, behind the B-24 and the multirole Ju 88. [END] 
Answer: 
United States
United States