Kinda wonder why back during B-17’s massive bomb runs to Germany they didn’t have several “Old Lady 666” kind to fight off the German fighters?
They did... (and it didn’t work very well)
http://www.defensemedianetwork.com/stories/my-brilliant-mistake-the-yb-40/
There was a heavily up-gunned B-17, YB-40, with multiple powered turrets and no bomb load. The weight saved was devoted to carrying extra .50-cal ammo.
Unfortunately, the modifications changed the aircraft’s basic outline sufficiently for it to be easily identified by attacking German fighter aircraft. But, that wasn’t the worse problem.
After the bomb run was completed the aircraft couldn’t keep up with the rest of the formation, it was significantly heavier than the empty B-17s returning to England.