Curious to see aircraft that never made it big. Here is one:
Boeing YB-40 - as if attacking a regular B-17 wasn't tough enough.
http://en.wikipedia.org/wiki/Boeing_YB-40_Flying_Fortress
Boeing YB-40 - as if attacking a regular B-17 wasn't tough enough.

http://en.wikipedia.org/wiki/Boeing_YB-40_Flying_Fortress