Boeing XB-39 Superfortress
PROTOTYPE BOMBER AIRCRAFT BY BOEING
XB-39; Boeing XB-39; Boeing B-39; XB-39 Superfortress; B-39 Superfortress; Boeing B-39 Superfortress
The Boeing XB-39 Superfortress was a United States prototype bomber aircraft, a single example of the B-29 Superfortress converted to fly with alternative powerplants. It was intended to demonstrate that the B-29 could still be put into service even if the first choice of engine, the air-cooled Wright R-3350 radial engine, ran into development or production difficulties.