The Martin Model 167 Maryland was an American-designed light bomber that first flew in 1939. It saw action in World War II with France and the United Kingdom. In response to a United States Army Air Corps light bomber requirement issued in 1938, the Glenn L. Martin Company produced its Model 167, which was given the official designation XA-22. Martin's design was a twin-engine all-metal monoplane, capable of around 310 mph (500 km/h) with a crew of three. The XA-22 was not adopted for operational service in the U.S., as the contract was won by the Douglas DB-7, which became the A-20 Havoc, but Martin received foreign orders, and about 450 of these fast, twin-engined bombers were built. The prototype Model 167W was powered by twin-row Pratt & Whitney R-1830-37 Twin Wasp engines, which were replaced in French production aircraft by single-row nine-cylinder Wright R-1820 Cyclone engines, although the Twin Wasps were then restored for the British Maryland. All versions of the Model 167 were armed with six machine guns, four fixed guns in the wings (mainly for ground-attack), one dorsal gun and one ventral gun. In the prototype, these guns were all 0.30 in Browning machine guns. The dorsal gun was mounted in a fully retractable turret. The French aircraft used license-built Belgian Fabrique Nationale FN-Brownings, and used a lighter semi-retractable dorsal turret. The weight saved helped to increase the top speed to 288 mph (463 km/h). The Model 167 was a fairly typical twin-engined bomber of the period. The most unusual feature of the Model 167 was the very narrow fuselage, although it was shared with a number of late prewar contemporaries. The crew of three was carried in two isolated compartments: the bombardier sat in the nose below the pilot and the gunner was in the mid-upper twin-machine gun turret in a separate rear compartment, isolated by a bulkhead. Glenn L. Martin doubled the size of the Baltimore factory, and built all 115 aircraft in six months, but they were then prevented from delivering them by a US government arms embargo. Despite this the French placed an order for an additional 100 aircraft. The embargo was lifted in October 1939, and the 115 aircraft from the first order were delivered by late November 1939. Deliveries then slowed, and only 25 of the second batch reached France before the Armistice of 22 June 1940. For details of the operational history in French and British service, click here.