PB-5 Clipper

Warning spoilers through Devil's Due.The PB-5 Clipper is a large transport/patrol/bomber used by the Alliance. It is basically an upgraded version of the PB-2. It features 4 W/G type engines with an average of 150hp each and a max speed of 90mph and an over all weight of around 4,800 lbs. It contains 3 crew men and the complicity to carry 8 passengers. It can also be fitted with 1,500 lbs bombs.

PB-5B
The PB-5B is an upgraded version of the above but with 4 MB radial engines with an average 254hp and a max speed of 125mph, rather than the in-line W/G type. It can carry 10 passengers and/or 2,000 lb bombs.

PB-5D
PB-5D "Clipper" has stacked engines and mounted defensive weapons with hardpoints for ordnance. Taylor included as a teaser with other art. Note stacked engines for more power. Taylor wrote "I'm tossing you a preview of the new "D" Model that will be briefly alluded to in "Straits."  The D model uses the same airframe as the B, but stacks the radials, returns to the fixed wing floats, and boasts hard points under the wings."

Note the mounted Browning Machine Gun M-1917 copies for defense.