The Lockheed Ventura was designed as a military version of the Lockheed Model 18. Great Britain placed an initial order for the Ventura Mk.I (Model 37-21-01) in February 1940. The RAF Air Ministry increased the initial order to 300 aircraft in May and submitted a follow-on order for 375 more aircraft later in 1940. These 675 aircraft were on order for about a year before the first flight of a Ventura Mk.I occurred on July 31, 1941.
Great Britain ordered 487 more Mk.II Venturas (Model 37-27-01) for distribution to the RAF, RCAF and SAAF; however, the USAAF diverted 264 aircraft for its own use. The first aircraft to actually carry the B-34 designation was the Ventura Mk.IIA (Model 137-27-02). Two hundred were ordered by the Army in 1941. Some of these were diverted for RAF, RAAF and RNZAF use.
An order for 550 improved versions of the Ventura was placed on Aug. 8, 1941. This aircraft was initially designated O-56, then RB-34B and finally B-37. Only 18 B-37s were completed before the contract was canceled.
TECHNICAL NOTES (B-34A): Armament: Four .50-cal. and six .30-cal. machine guns plus 3,000 lbs. of bombs Engines: Two Pratt & Whitney R-2800-21 radials of 2,000 hp each (takeoff power) Maximum speed: 315 mph at 15,000 ft. Cruising speed: 230 mph Range: 2,600 miles (maximum ferry range); 950 miles with full bomb load Service ceiling: 24,000 ft. Span: 65 ft. 6 in. Length: 51 ft. 5 in. Height: 11 ft. 11 in. Weight: 27,750 lbs. (maximum gross weight) Crew: Four Serial numbers: 41-38020 to 41-38219