Martin Maryland

The Martin Model 167 was a U.S.-designed light bomber that first flew in 1939. It saw action in World War II with France and the United Kingdom, where it was called the Maryland.

Design and development

Martin XA-22, 13 April 1939.

In response to a U.S. Army Air Corps light bomber requirement issued in 1938, the Glenn L. Martin Company produced their Model 167, which was given the official designation XA-22. Martin's design was a twin-engine fully metallic monoplane, capable of around 310 mph (447 km/h) and carrying a crew of three. The bombardier sat in the nose below the cockpit, and self-defense was provided by a mid-upper twin-machine gun turret, as well as four forward firing light machine guns in the wings.

The XA-22 was not adopted for operational service in the U.S., as the contract was won by Douglas with its DB-7, but Martin received foreign orders, and about 450 of these relatively fast, twin-engined bombers were built.

The prototype Model 167W was powered by Pratt & Whitney R-1830-37 “Twin Wasp” engines, which were replaced in French production aircraft by Wright “Cyclone 9” engines (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.

The Model 167 was a fairly typical twin engined bomber. The crew of three were carried in two isolated compartments – pilot and bombardier in the nose and the gunner in a separate rear compartment, isolated by a bulkhead. The most unusual feature of the Model 167 was the very narrow width of the fuselage.

Glenn L. Martin doubled the size of their Baltimore factory, and built all 115 aircraft in six months, but they were then prevented from delivering them by a US arms embargo. Despite this the French placed an order for another 100 aircraft. The embargo was finally lifted in October 1939, and the 115 aircraft from the first order were delivered by the end of November 1939. After this impressively speedy start, things slowed down, and only 25 of the second batch of aircraft had reached France before the Armistice of June 1940.

Operational history

French service

A captured French Martin 167F at Aleppo, Syria, in 1941.

Facing a massive German arms buildup and desperate for modern aircraft, the French Air Force purchased U.S. aircraft of numerous types in the late 1930s. Martin received an order for more than 200 167 Fs which incorporated French-specific equipment such as metric instruments. French officials expected the deliveries to begin in January 1939 but the type, locally designated Glenn Martin 167 A-3 only entered service in early 1940.

Notably, because of the U.S. embargo on arms exports after the beginning of World War II, many aircraft were impounded for two months before being shipped to Europe. When the Germans eventually invaded France there were only four Groupes de bombardement (bomber squadrons) equipped. The Glenns were quickly sent to the front lines where they performed well with their adequate speed and excellent maneuverability for an aircraft in this class. They sometimes had a chance to avoid enemy fighters.^[1] In about 400 sorties versus the Germans, they suffered a loss rate of only 4%, much better than the 16% endured by LeO 451s and their crews above the same targets.

Immediately before the June 1940 Armistice, units flying the Glenn Martin 167 were evacuated to French North Africa to avoid capture by the Germans. One of them landed in Spain and was interned, being tested by the Spanish Air Force. ^{[citation needed]}Some examples were transferred to the Aéronautique Navale. During the Vichy rule on the French empire, French Martins occasionally clashed with British Commonwealth forces, most notably during the Syria-Lebanon campaign of 1941. As French North Africa got back in the Allied camp in 1943, M.167s were phased out of service and replaced with more modern Allied types, including Martin's B-26 Marauder.

Approximately 215 Martin 167s were delivered to France.

British service

Martin Maryland bombers fly past in formation, North Africa 1941

Just before the Franco-German Armistice, the remaining 75 planes on the French order were signed over to the United Kingdom. Thirty-two aircraft had been completed to French specifications and were converted to British requirements in the UK. Engines were changed from the Cyclone 9 to the Pratt and Whitney Twin Wasp and various weapons and instruments were replaced. The last 43 of the order were completed as required by Glenn Martin. All these aircraft received the designation Maryland Mk.I. A further 150 aircraft had been ordered directly by Britain with two-speed superchargers on their Twin Wasps and were designated Maryland Mk.II.^[2]

Many of the aircraft were shipped to Egypt and Malta in time for the 1941 fighting there. The RAF used the aircraft to some effect for photo-reconnaissance operations in North and Eastern Africa, sometimes as a bomber, being faster and better armed than the Bristol Blenheim, but since it was a "rare bird", its role was mainly reconnaissance missions, often flown over the most important Italian targets. A Maryland bomber was the aircraft sent to gather photographs of the Italian fleet before and after the Battle of Taranto on 11 November 1940.^[3] The pilot of that Maryland was the famous ace Adrian Warburton, who scored his five confirmed kills with the Maryland's forward-firing guns - the only person ever to achieve ace status in a bomber type.

Three Maryland Mk.I aircraft were transferred to the British Fleet Air Arm^[4] and were mainly used for target towing duties.^[5] On 22 May 1941, a Maryland of 771 Naval Air Squadron based at Hatston in the Orkney Islands, reported that the German battleship Bismarck had left Bergen, confirming that she was breaking-out into the Atlantic.^[6]

Operators

 France

• Armée de l'Air
• Aéronavale

 South Africa

• South African Air Force

 United Kingdom

• Royal Air Force
• Fleet Air Arm

Specifications (Maryland Mk I)

General characteristics

• Crew: 3 (Pilot, Navigator/Bomb Aimer/Gunner & Radio Operator/Gunner)
• Length: 46 ft 8 in (14.2 m)
• Wingspan: 61 ft 4 in (18.7 m)
• Height: 16 ft 3 in (5.0 m)
• Wing area: 537 ft² (49.9 m²)
• Empty weight: 10,586 lb (4,802 kg)
• Loaded weight: 15,297 lb (6,939 kg)
• Max. takeoff weight: 16,809 lb (7,624 kg)
• Powerplant: 2 × Pratt & Whitney R-1830-S1C3-G "Twin Wasp" radial engine, 1,050 hp (900 kW) each
• Propellers: 10 ft 11 in (3.3 m) Hamilton Standard 3T50 three-bladed constant-speed metal propellers
• Fuel capacity: 514 imperial gallons (2,336 litres)

Performance

• Maximum speed: 304 mph (489 km/h) at 13,000 ft (3,962 m)
• Cruise speed: 248 mph (399 km/h)
• Range: 1,300 miles (2,100 km)
• Service ceiling: 29,500 ft (8,991 m)
• Rate of climb: 2,400 ft/min (12 m/s)
• Wing loading: 28.5 lb/ft² (139.1 kg/m²)
• Power/mass: 0.157 hp/lb (259 W/kg)

• Guns: 4 x .303 (7.7 mm) Browning Mk II machine guns in outer wings with 750 rpg, 1 × .303 in (7.7 mm) Vickers K machine gun in dorsal and ventral step positions each with 5 x 97-round magazines
• Bombs: 2,000 lb (907 kg) internally; (Usually 4 x 500 lb (227 kg) bombs)

See also

Related development

• Martin Baltimore

Related lists

• List of aircraft of World War II
• List of aircraft of the Royal Air Force
• List of aircraft of the Armée de l'Air, World War II
• List of military aircraft of the United States

References

Notes

Bibliography

External links

Wikimedia Commons has media related to Martin Maryland.

• Fleet Air Arm Archive article
• "The French Martin" a 1940 Flight article