l anta . ▁The ▁B - 2 9 B ▁was ▁a ▁limited ▁production ▁aircraft , ▁built ▁sole ly ▁by ▁Bell - At l anta . ▁It ▁had ▁all ▁but ▁the ▁tail ▁def ensive ▁arm ament ▁removed , ▁since ▁experience ▁had ▁shown ▁that ▁by ▁ 1 9 4 4 ▁the ▁only ▁significant ▁Japanese ▁f ighter ▁attacks ▁were ▁coming ▁from ▁the ▁rear . ▁The ▁tail ▁gun ▁was ▁aim ed ▁and ▁fired ▁automatically ▁by ▁the ▁new ▁AN / AP G - 1 5 B ▁rad ar ▁fire ▁control ▁system ▁that ▁detected ▁the ▁approaching ▁enemy ▁plane ▁and ▁made ▁all ▁the ▁necessary ▁calculations . ▁The ▁elim ination ▁of ▁the ▁tur rets ▁and ▁the ▁associated ▁General ▁Electric ▁computer ized ▁gun ▁system ▁increased ▁the ▁top ▁speed ▁of ▁the ▁Super fort ress ▁to ▁ 3 6 4   m ph ▁at ▁ 2 5 , 0 0 0 ▁feet ▁and ▁made ▁the ▁B - 2 9 B ▁suitable ▁for ▁fast , ▁un esc orted ▁hit - and - run ▁bomb ing ▁ra ids ▁and ▁phot ographic ▁miss ions . ▁ ▁M oved ▁to ▁North west ▁Field , ▁Gu am , ▁April – J une ▁ 1 9 4 5 , ▁and ▁assigned ▁to ▁the ▁ 3 1 5 th ▁Bomb ▁Wing , ▁Tw enti eth ▁Air ▁Force . ▁Bom bed ▁Japanese - h eld ▁Tru k ▁late ▁in ▁June ▁ 1 9 4 5 . ▁Fle w ▁first ▁mission ▁against ▁the ▁Japanese ▁home ▁islands ▁on ▁ 9 ▁July ▁ 1 9 4 5 ▁and ▁after ward ▁operated ▁princip ally ▁against ▁the