The Boeing Model 299 in flight in 1935.
USAAC
1935
USAF museum website, USAF photo no. 060706-F-1234S-001 <a rel="nofollow" class="external autonumber" href="https://media.defense.gov/2006/Jul/06/2000549767/-1/-1/0/060706-F-1234S-001.JPG">[1]</a>, retrieved 2009-04-02; source link updated 2018-05-02 from gallery <a rel="nofollow" class="external autonumber" href="https://www.nationalmuseum.af.mil/Upcoming/Photos/igphoto/2000549767/">[2]</a>.