The Boeing XB-44 Superfortress was a United States B-29 Superfortress bomber aircraft upgraded with Pratt & Whitney R-4360-33 Wasp Major radial engines of 3 000 horsepower (2 200 kW) takeoff rating in place of the production engines rated at 2 200 hp (1 600 kW) takeoff rating.
Made by Boeing.
It is the successor of the Boeing B-29 Superfortress .