The Lockheed XB-30 was a bomber version of the C-69/ C-121/ Constellation, developed in response to the same specifications that produced the B-29 Superfortress.
The Model 249 would have been powered by four 2,200hp Wright R-3350-13 engines. It would have been armed with ten 0.50in machine guns and one 20mm cannon, split between two dorsal turrets, two ventral turrets, one nose turret and one tail turret. It would have been able to carry 16,000lb of bombs. Estimated top speed would have been 382mph at 25,000ft. It was expected to have a range of 5,000 miles carrying 6,000lb of bombs.
Lockheed were given a contract for preliminary engineering date on 27 June 1940, along with Boeing (XB-29), Douglas (XB-31) and Consolidated (XB-32). Lockheed soon withdrew from the project, although not before producing a model of the proposed aircraft, which shows it as being very similar to the standard Constellation, with the same circular fuselage, low mounted wings and triple rudder tail. It would also have had a glazed nose for the bombardier. The tail was slightly extended to carry the tail turret.
Engines: Four Wright R-3350-13
Wing span: 123ft
Length: 104ft 3in
Height: 23ft 9.5in
Empty weight: 51,725lb
Loaded weight: 86,000lb
Maximum speed: 382mph at 25,000ft
Cruising speed: 240moh
Service ceiling: 40,000 miles
Normal range: 5,000 miles with 6,000lb payload; 3,380 miles at 240mph
Armament: ten 0.50in machine guns and one 20mm cannon
Payload: 16,000lb bombs