A few months ago I took an Appleseed rifle skills course. It's amazing what goes inyo "just" hitting a static target from a static position at 25 yards with soft time constraints. It's amazing what goes into hitting a moving target from a moving plane in a few seconds.
https://www.youtube.com/watch?v=UOX-2d9qLec
The B-29 also had ECM detectors and transmitters, so they could block enemy radar signals.