Changes

Model 345 boasted many features that Boeing had had under development since 1934, among them:

Model 345 boasted many features that Boeing had had under development since 1934, among them:

* A long, narrow, high-aspect-ratio wing with Fowler flaps for increased lift. This allowed for much heavier base and take-off weights.<ref name=Boeing1/>

* A long, narrow, high-[[aspect ratio|aspect-ratio]] wing with Fowler flaps for increased lift. This allowed for much heavier base and take-off weights.<ref name=Boeing1/>

* Three pressurized crew areas: flight deck, gunner's compartment, and tail gunner's station.<ref name=NASM/><ref name=Boeing1/> The first two of these were connected by a long tube over the bomb bays;<ref name=ace/> the tail gunner's station remained isolated, and ingress and egress were possible only on the ground or at an altitude that did not require pressurization.<ref name=Boeing1/><ref name=ace/>

* Three pressurized crew areas: flight deck, gunner's compartment, and tail gunner's station.<ref name=NASM/><ref name=Boeing1/> The first two of these were connected by a long tube over the bomb bays;<ref name=ace/> the tail gunner's station remained isolated, and ingress and egress were possible only on the ground or at an altitude that did not require pressurization.<ref name=Boeing1/><ref name=ace/>

* Remote-control gun turrets, and a sighting system that allowed one gunner to control two or more turrets at once to concentrate on a single target.<ref name=NASM/>

* Remote-control gun turrets, and a sighting system that allowed one gunner to control two or more turrets at once to concentrate on a single target.<ref name=NASM/>