Five remote-controlled cannons with computer-aided aiming made the Superfortress way, way ahead of its time.
It could cruise at over 300 mph and it could hit 410mph during a dash. Considering that the aircraft could carry 8,000 lbs of weapons and had a range approaching 2,000 miles, the Mixmaster looked like it would become a huge success. But the tide of World War II was changing and the B-29 ended up being everything that it promised. Jet engine technology was emerging as the wave of the future, leaving little room for piston engine-based designs. This left the XB-42 without a production contract.