In support of an official event 

The Museum will be closed Sunday, May 25
In addition, the Fourth Hangar will be closed Saturday, May 24

Guided tours of the 4th building, normally scheduled at 3:00 p.m. daily, are canceled through May 28.

Effective immediately, the William E. Boeing Presidential Gallery will have limited guest access due to scheduled event preparations. The only accessible exhibits during this time include: Douglas VC-54 Sacred Cow, Flying the President Exhibit, USAF Established Artifact. We anticipate full gallery access will resume by June 5, 2025.

Proving the Flying Fortress

As a result of the General Staff's decision, only 13 YB-17s and one YB-17A were ordered by mid-1937 as compared to 133 B-18s and 177 B-18As. The Air Corps was determined to prove the value of the four-engine B-17 with this handful of service test planes. It flew its YB-17s at every opportunity over the U.S. and even scheduled good will flights to South America to demonstrate the long-range capabilities of the plane. It eventually proved its point, and by the end of 1938, contracts for 39 additional B-17Bs were awarded. In addition, a new four-engine bomber, the Consolidated XB-24, was ordered on March 30, 1939. At the time World War II began in Europe in September 1939, the first B-17Bs were beginning to come off the production line. 

Click here to return to the Four-Engine Bomber Overview.