Country of origin:

United States of America

Description:

Twin-engine bomber and reconnaissance aircraft

Power Plant:

Two 895 kw (1,200 hp) Wright Cyclone GR-1820-G105A nine-cylinder air-cooled radial engines

Specifications:

Armament:

One 7.62 mm (0.30 in) machine gun in nose turret; one 7.62 mm (0.30 in) machine gun in each of dorsal and ventral positions; max bomb load 570 kg (1,260 lb)

History:

The Martin Model 123 was designed and built as a private venture, this being an attempt by Glenn L Martin Co to obtain contracts from the United States Army for an aircraft to be involved in early bomb-dropping experiments. Delivered in July 1932 to Wright Field, Ohio it had two 448 kw (600 hp) SR-1820-E Cyclone engines and a crew of three. Later that year it was fitted with a nose gun turret and R-1820-19 engines and, now known as the XB-907A, was found to be faster than any US fighter in service, having a maximum speed of 333 km/h (207 mph).

A contract was placed for 48 aircraft and the first production aircraft (Martin 139s) were delivered in June 1934. A number of different power plants were tried, including the R-1820-25 of 504 kw (675 hp), the R-1690-11 Hornet of 578 kw (775 hp), the turbo-supercharged R-1820-31, this becoming the YB-10A and having a maximum speed of 380 km/h (236 mph), and the 709 kw (950 hp) YR-1830-9 Twin Wasp.

Known in service as the B-10 and B-12, they were initially used for coastal defence duties, some being fitted with skis and a number with twin floats for operations off water. Variants included the YB-12A with 578 kw (775 hp) Pratt & Whitney R-1690-11 radial engines; and the XB-14 with 709 kw (950 hp) Pratt & Whitney Twin Wasps. The B-10 was the first US bomber to employ a nose turret. A number were modified for target towing, becoming the B-10M and B-12M. The type remained in service with Army bomber units until the introduction into service of B-17s and B-18s in the late 1930s.

In 1936 Glenn L Martin Co accepted an order for 13 aircraft known as the Model 139W for the Netherlands East Indies Air Force, these to be fitted with 634 kw (850 hp) Wright GR-1820-G2 engines. Orders were also received from China, Argentina and Turkey; and one was supplied to Russia. In 1938 a special export model appeared, initially known as the Model 139-WH3 but which later became known as the Model 166. This model differed externally in having a long glasshouse type canopy and a number of these were supplied also to the NEIAF.

The first Dutch machine (serial M501 – c/n 656) was a WH-1 handed over at Baltimore, Maryland in September 1936. Dutch B-10s included 13 Model 139Ws and 104 Model 139WH3s. However, they lacked armour protection and had an inadequate defensive armament. Those supplied to China were operated against the Japanese mainland.

In May 1941 three Dutch WH-3As visited RAAF base Darwin, NT a few months before entering the conflict with Japanese forces. Following the Japanese attacks they were used extensively from their bases in Singapore, Borneo and Batavia but suffered badly. In Singapore they were on occasions escorted by Australian crewed Brewster Buffalos.

After the fall of the Dutch East Indies surviving aircraft that could be flown south were flown to Australia. One B-10 (serial M585 – c/n 843), the sole airworthy survivor of the type, was flown from Andir to Australia on 8 March 1942, arriving at Broome, WA nine hours later flown by Lt P J P Erkel and Lt A B Wolff.  ML-KNIL crews hoped to operate the aircraft from Australia against Japanese forces. Dutch crews also put forward using it to make a bond raising tour of the United States with a Dutch crew. However, it, like the 11 Lockheed Lodestars which managed to escape, was part of an agreement of 8 April 1942 relating to surviving aircraft of the KNILM reached between the Netherlands East Indies Government and the USAFIA. In fulfilment of the agreement the B-10 was obtained from the Dutch Government and issued with USAAC serial 42-68358, being operated by the USAAF.

Carrying the name ‘Miss Latrine 1930’ it operated in an overall natural metal colour scheme with USA markings and the nose turret faired over. It seems at some stage it had a wheels-up landing in the Mascot, NSW area and was repaired, making a test flight on 24 July 1943. It made further local flights on 7 and 13 August that year. On 14 August it was flown from Mascot to Eagle Farm, QLD in a time of 2 hours 40 mins and was transferred to the 81st Depot Repair Squadron. Having the same engines as the ex-Dutch Lockheed Lodestars it saw some service within Australia, but eventually, through lack of spares, was withdrawn from service in June 1944, written off on 31 August 1944 and broken up.

It is interesting to note that a number of the ex-Dutch Martin B-10s left behind on Java were restored to airworthiness by Japanese crews, and one example was flown to Japan. At least 15 were made serviceable, and a few survived up until 1949 in Thai service.