The Consolidated B-32 Dominator (Consolidated Model 34) was an American heavy strategic bomber built for United States Army Air Forces during World War II, which had the distinction of being the last Allied aircraft to be engaged in combat during World War II. It was developed by Consolidated Aircraft in parallel with the Boeing B-29 Superfortress as a fallback design should the B-29 prove unsuccessful. The B-32 only reached units in the Pacific during mid-1945, and subsequently saw only limited combat operations against Japanese targets before the end of the war. Most of the extant orders of the B-32 were canceled shortly thereafter and only 118 B-32 airframes of all types were built. The engineering development of the B-29 had been underway since mid-1938 when, in June 1940, the United States Army Air Corps requested a similar design from the Consolidated Aircraft Company in case of development difficulties with the B-29. The Model 33 on which Consolidated based its proposal was similar to the B-24 Liberator. Like the B-24 it was originally designed with a twin tail and a large Davis wing, but with a longer, rounder fuselage and a rounded nose. The powerplants were to be the same quartet of eighteen-cylinder, 2,200 horsepower (1,600 kW) Wright Duplex-Cyclones, as specified for B-29s. The aircraft was designed to be pressurized, and have remote-controlled retractable gun turrets with fourteen .50 in (12.7 mm) machine guns. It was to have an estimated gross weight of 101,000 lb (46,000 kg). The first contract for two XB-32s was signed on 6 September 1940, the same day as the contract for the Boeing prototype XB-29. Due to problems with the pressurization system, the gun turrets and landing gear doors, these items were omitted on the first prototype. The aircraft had R-3350-13 engines inboard and R-3350-21s outboard, with all four powerplants driving three-bladed propellers. The XB-32 had persistent problems with engine oil leaks and poor cooling, but the B-29 also had similar engine problems. The inboard propellers' pitch could be reversed to shorten the landing roll or to roll back in ground maneuvers. The first XB-32 was armed with eight .50 in (12.7 mm) machine guns in dorsal and ventral turrets, and an odd combination of two .50 caliber and one 20 mm (0.787 in) cannon in each outboard engine nacelle firing rearwards, plus two .50 caliber machine guns in the wings outboard of the propellers. The turrets were remotely controlled from periscopic sights in aiming stations inside the aircraft. The sights were coordinated by a sophisticated analog computer system developed by Sperry Gyroscope Company. For further details of the development and design, operational history and variants of the B-32, click here.