This group is open to everyone who likes any kind of aircraft
The Boeing YB-40 Flying Fortress was a modification of the United States B-17 Flying Fortress bomber aircraft, converted to act as a heavily-armed escort for other bombers during World War II. At the time of its development, long-range fighter aircraft such as the P-51 Mustang were just entering quantity production, and thus were not yet available to accompany bombers all the way from England to Germany and back. Now retired, no known survivors.
What was so heavily armored about it? From this pic, looks like all the other B17g's
It Accuttully Had an 3rd Extra Layer of Thick armor from AA guns
And a crap-load of MGs...