The Martin MB-2 was essentially an improved and slightly enlarged version of the Martin MB-1. The MB-2 can be distinguished from the MB-1 by noting the engines on the MB-2 were lowered to the bottom wing. The MB-1 engines were suspended between the wings. Twenty MB-2s were ordered by the U.S. Army in 1920, and Martin built only the first five as MB-2s. The remaining 15 were built as NBS-1 (Night Bombardment-Short Distance) when the Army adopted a new designation scheme.
During the post-World War I era, the Army usually purchased the aircraft design and contracted the actual construction to the lowest bidder. In the case of the MB-2 (NBS-1), four firms built the aircraft. Martin only built the first 20 aircraft. The remaining 110 aircraft were built by Curtiss (50 aircraft), LWF (35 aircraft) and Aeromarine (25 aircraft).
The MB-2's (AS 64195) first flight was on Sept. 3, 1920. Twenty Curtiss-built NBS-1s (AS 68508 to 68527) were fitted with superchargers allowing the aircraft to climb as high as 25,600 feet.
The most notable contribution of the MB-2 (NBS-1) was as the aircraft used in the famous ship bombing trials in 1921. Flying out of Langley Field, Va., under the command of Brig. Gen. Billy Mitchell, the Martin Bombers sunk a destroyer, cruiser and a battleship and proved the worth of aerial bombardment.
TECHNICAL NOTES: Armament: Five .30-cal. machine guns and 2,000 lbs. of bombs Engines: Two Liberty 12-As of 400 hp each Maximum speed: 98 mph at sea level Cruising speed: 91 mph Range: 400 miles Service ceiling: 7,700 ft. (9,900 ft. absolute ceiling) Span: 74 ft. 2 in. Length: 42 ft. 8 in. Height: 14 ft. 8in. Weight: 12,027 lbs. gross Serial numbers: AS 64195 to 64199