A derivative of the first US-designed bomber, the Martin MB-1, the MB-2 featured a number of improvements. Twenty MB-2s were ordered in June 1920, and the type was rushed into production so that Brig. Gen. William L. "Billy" Mitchell could use the aircraft in the planned strategic bombing tests off the Virginia Capes. From July 13–21, 1921, General Mitchell's 1st Provisional Air Brigade, based at Langley Field, Va., sank three ships, including the captured German battleship Ostfriesland, and demonstrated the vulnerability of naval vessels to aerial attack. The Air Service then ordered another 110 aircraft, which were designated NBS-1 for "Night Bombing, Short-Range." Curtiss underbid Martin (which had included development costs in its bid of $23,485 per aircraft) and received a contract for 50 aircraft (although Curtiss lost money on the program), while L. W. F. Engineering and Aeromarine received contracts for 35 and 25 aircraft, respectively. Martin then provided its competitors with drawings, parts lists, templates, and even jigs, so all the aircraft were essentially identical. The type was retired in 1928. (Specifications for MB-2.)

Contractors:	Glenn L. Martin Co.
	L. W. F. Engineering Co.
	Curtiss Aeroplane and Motor Co.
	Aeromarine Plane and Motor Co.
Locations Built:	Cleveland, Ohio.
	College Point, N. Y.
	Garden City, N. Y.
	Keyport, N. J.
Number Built: (USAF)	130 (130)
First Flight:	1921
First Flight Model:	MB-2
First Flight Location:	Cleveland, Ohio
First Flight Pilot:	Unconfirmed
Models/Variants:	MB-2
	NBS-1
Powerplant:	Two Packard Liberty 12A liquid-cooled V-12s of 420 hp each.
Wingspan:	74 ft 2 in.
Length:	42 ft 8 in.
Height:	15 ft 63/4 in.
Weight:	13,695 lb gross.
Armament:	Five .30-cal. Lewis machine guns in nose and amidships; 1,800 lb of bombs internally and up to 2,000 lb of bombs externally.
Accommodation:	Four (pilot, copilot/navigator, bombardier/gunner, and rear gunner).
Max. Speed:	101 mph.
Range:	560 mi.
Ceiling:	8,500 ft.