Martin 139, South American and European Users

 

The Martin 139 (known in service with the United States Army Air Corps - USAAC) as B-10, was an American all-metal bomber, one of the first mass-produced in the 1930s that saw service with various countries. On this post we're covering the next ones:

• Argentina: Both Argentine Comando de Aviación del Ejército (Army Aviation Command) and Armada Argentina (Argentine Navy) used the Type 139. 
  In the mid-1930 the Army Aviation Command sought to modernise their bomber fleet and, in February 1937, after having studied other choices, they signed a contract with Martin for a total of 22 machines, which were designated by the company as Martin Type 139WAA (with the demonstrator being denominated just as Type 139WA). The bombers were assigned to the Regimiento de Aviación Nº1 (No.1 Aviation Regiment) at El Palomar Air Base, close to the capital, Buenos Aires and Regimiento 1 de Bombardeo (Bombing Regiment 1) of Villa Reynolds in the province of San Luis. They served until 1954, however, by that year the last three ones were being used as target tows. They were replaced by the native IAe-24 Calquin.
  The Argentine Navy acquired also a total of 12 new aircraft, plus a demonstrator, designated by the company as Type 139WAN. The contract was signed on 24th December 1936 and they were delivered in November 1937. They were assigned to two newly-formed bomber squadrons, one based at Punta Indio Naval Air Base, close to Buenos Aires and other one based at Comandante Espora Naval Air Base, close to Buenos Aires too. 
  This type was chosen by the Navy as the fuselage featured watertight compartments that could help with floatability in case of an emergency landing on sea and the type could also be fitted with EDO-made floaters. They also were the first airplane to feature a retractable landing gear to operate with the Argentine Navy. They all served until 1949.
• USSR: One aircraft, denominated by Martin as Martin Type 139WR, powered by two Wright R-1820-F53 Cyclone engines and Hamilton screws was bought by the Soviet Union for evaluation purposes. It seems that the performance of this machine wasn't satisfactory as no further machines were ordered by the Soviets and nothing is known about the fate of the aircraft. As there doesn't seem to be any graphical evidence of the type serving in Soviet colours, the drawing should be considered as speculative.
• Republic of Spain: The Spanish Republican Government had closed a deal for several Martin 139WSP (denomination given by the company), just before the outbreak of the Spanish Civil War. This deal also included the licensed production of the type by CASA, however, it was eventually blocked by the US State Department and the type was never delivered. When the Soviet Tupolev SB Katyusha appeared over the Spanish skies, many sources initially misidentified it as a "Martin Bomber"(which shouldn't come as a surprise as the Soviet aircraft types were kept under secrecy back in the 1930s).
  The presence of the 139WSP in the Spanish Civil War is even quoted by many authors and there are even some manipulated photographs, made with obvious propaganda purposes. We decided to draw a fictional version of the type serving with the Republican side.

Sources:

1. https://en.wikipedia.org/wiki/Martin_B-10

2. http://www.amilarg.com.ar/martin-139.html (translated)

3. https://web.archive.org/web/20200920135216/http://bioold.science.ku.dk/drnash/model/Spain/didnt.html

4. https://www.globalsecurity.org/military/systems/aircraft/b-10-foreign.htm