View source for Martin B-10

{{Short description|American bomber aircraft}}
{{Use dmy dates|date=December 2019}}
{{Infobox aircraft
 |name=B-10
 |image=File:Martin-B-10B.jpg
 |image_caption=B-10 being flown during a training session at [[Maxwell Air Force Base|Maxwell Field]]
 |aircraft_type= [[Bomber aircraft]]
 |manufacturer=[[Glenn L. Martin Company]]
 |designer=[[Peyton M. Magruder]]
 |first_flight=16 February 1932
 |introduction=November [[1934 in aviation|1934]]
 |retired=[[1949 in aviation|1949]] ([[Royal Thai Air Force]])
 |primary_user=[[United States Army Air Corps]]
 |more_users=[[Royal Netherlands East Indies Army Air Force|Netherlands East Indies Air Force]]<br/>[[Turkish Air Force]]
 |produced=[[1933 in aviation|1933]]–[[1940 in aviation|1940]]
 |number_built={{ubl
  | 121 B-10
  | 82 model 166
  | 32 B-12
  | 348 of all variants, incl. 182 export versions
  }}
 |variants=[[Martin Model 146]]
}}

The '''Martin B-10''' is a [[bomber]] aircraft designed by the [[Glenn L. Martin Company]]. Entering service in June 1934, it was the first all-metal [[monoplane]] bomber to be regularly used by the [[United States Army Air Corps]].<ref name="jackson">Jackson 2003, p. 246.</ref> It was also the first mass-produced bomber whose performance was superior to that of the Army's [[fighter aircraft|pursuit]] [[aircraft]] of the time.<ref name="world1">Eden and Moeng 2002, p. 931.</ref>

The B-10 served as the airframe for the '''B-12''', '''B-13''', '''B-14''', '''A-15''', and '''O-45''' designations – using [[Pratt & Whitney]] engines instead of [[Wright Cyclone]]s. A total of 348 of all versions were built. The largest users were the US, with 166, and the Netherlands, with 121.

==Design and development==
[[File:25th_Bombardment_Squadron_B-10s.jpg|thumb|Martin B-10, [[25th Bombardment Squadron]], Panama Canal Zone]]
[[File:Martin B-10 Variant.jpg|thumb|Martin B-10 during exercises over Oahu, Hawaii, 1941]]

The B-10 began a revolution in bomber design. Its all-metal monoplane airframe, along with its features of closed cockpits, rotating gun turrets (almost simultaneously with the 1933 British [[Boulton & Paul Overstrand]] biplane bomber's own enclosed nose-turret), retractable landing gear, internal bomb bay, and full engine cowlings, became the standard for bomber designs worldwide for decades.<ref name="world1"/> It made all existing bombers completely obsolete. Martin received the 1932 [[Collier Trophy]] for designing the XB-10.<ref>''Collier Trophy Is Presented to Martin'', 1 June 1933.</ref>

The B-10 began as the '''Martin Model 123''', a private venture by the [[Glenn L. Martin Company]] of [[Baltimore, Maryland]]. It had a crew of four: [[Aviator|pilot]], copilot, nose [[Air gunner|gunner]] and fuselage gunner. As in previous bombers, the four crew compartments were open, but it had a number of design innovations as well.<ref name="Flying Fish">[https://books.google.com/books?id=aygDAAAAMBAJ&pg=PA51 "Flying Fish–Our Army's Newest Plane Hits Terrific Speeds (photo of Model 123, US Army designation XB-907, in flight)."] ''Popular Science,'' October 1932. Retrieved: 22 December 2010.</ref><ref name="M=List">[http://aerofiles.com/_martin.html "M-list."] ''Aerofiles.'' Retrieved: 22 December 2010.</ref>

These innovations included a deep belly for an internal [[bomb bay]] and [[Landing gear|retractable main landing gear]]. Its {{cvt|600|hp|kW|0}} [[Wright R-1820|Wright SR-1820-E]] Cyclone engines provided sufficient power. The Model 123 first flew on 16 February 1932 and was delivered for testing to the [[U.S. Army]] on 20 March as the XB-907. After testing it was sent back to Martin for redesigning and was rebuilt as the '''XB-10'''.<ref name="Flying Fish"/><ref name="M=List"/>

The XB-10 delivered to the Army had major differences from the original aircraft. Where the Model 123 had [[Townend ring]]s, the XB-10 had full [[NACA cowling]]s to decrease [[Aerodynamic drag|drag]].<ref name="fitz46">Fitzsimons 1969, p. 1846.</ref> It also sported a pair of {{cvt|675|hp|kW|0}} [[Wright R-1820]]-19 engines, and an {{convert|8|ft|m|adj=on}} increase in the wingspan, along with an enclosed nose turret. When the XB-10 flew during trials in June, it recorded a speed of {{cvt|197|mph|km/h|0}} at {{cvt|6000|ft|m|0}}. This was an impressive performance for 1932.<ref name="world1"/>

Following the success of the XB-10, a number of changes were made, including reduction to a three-man crew and addition of [[canopy (aircraft)|canopies]] for all crew positions. The Army ordered 48 of these on 17 January 1933. The first 14 aircraft were designated '''YB-10''' and delivered to [[Wright Field]], starting in November 1933, and used in the [[Air Mail scandal|Army Air Corps Mail Operation]]. The production model of the XB-10, the YB-10, was very similar to its prototype.{{citation needed|date=July 2016}}

==Operational history==
{{Expand section|date=July 2016}}

===United States===
[[File:Martin B-10B during exercises.jpg|thumb|Martin B-10B during exercises]]
[[File:Martin B-12 at March Field, Calif., on Nov. 19, 1935.jpg|thumb|Martin B-12 at [[March Field]], California, 1935]]

In 1935, the Army ordered an additional 103 aircraft designated '''B-10B'''. These had only minor changes from the YB-10. Shipments began in July [[1935 in aviation|1935]]. B-10Bs served with the [[2d Operations Group|2d Bomb Group]] at [[Langley Field]], the [[9th Operations Group|9th Bomb Group]] at [[Mitchel Field]], the [[19th Operations Group|19th Bomb Group]] at [[March Field]], the [[6th Operations Group|6th Composite Group]] in the [[Panama Canal Zone]], and the 4th Composite Group in the [[Philippines]]. In addition to conventional duties in the bomber role, some modified YB-10s and B-12As were operated for a time on large twin floats for coastal patrol.<ref name="world2">Eden and Moeng 2002, p. 932.</ref><ref name="ohnine">Swanborough and Bowers 1964, p. 331.</ref>

In February 1936, the US Army Air Corps used 13 B-10Bs of the [[49th Bomb Squadron]] to drop supplies to the residents of [[Virginia]]'s [[Tangier Island]] and [[Maryland]]'s [[Smith Island, Maryland|Smith Island]]; with ships unable to reach the islands due to heavy ice in the [[Chesapeake Bay]], the islanders faced starvation after a severe winter storm. The B-10B supply flights followed earlier supply flights to the islands by the [[Goodyear Blimp]] ''Enterprise'' on 2 February 1936 and by the squadron's [[Keystone B-6|Keystone B-6A]] bombers on 9 and 10 February 1936.<ref name="TouchofGreatnesspp4142">[https://books.google.com/books?id=OsIBdVV_YOAC&pg=PA43&lpg=PA43 Bentley, Stewart W., Jr., PhD., ''The Touch of Greatness: Colonel William C. Bentley, Jr., USAAC/USAF; Aviation Pioneer''], Bloomington, Indiana: AuthorHouse, 2010, {{ISBN|978-1-4490-2386-7}}'', pp. 41–42.''</ref><ref>Anonymous, "Bombing Planes to Bring Food to Ice Victims," ''Chicago Tribune'', 2 February 1936.</ref>

With its advanced performance, the Martin company fully expected that export orders for the B-10 would flood in. The U.S. Army owned the rights to the Model 139 design. Once the Army's orders had been filled in 1936, Martin received permission to export Model 139s, and delivered versions to several air forces. These included six Model 139Ws sold to [[Siam]] in April 1937, powered by [[Wright R-1820]]-G3 Cyclone engines, and 20 Model 139Ws sold to [[Turkey]] in September 1937, powered by R-1820-G2 engines.{{citation needed|date=July 2016}}

===China===

In July 1936, the Martin B-10 was put up for export, with the first sale being made to the [[Republic of China Air Force]] in the same year, purchasing six Model 139WC-1s and three Model 139WC-2s.<ref>{{Cite book |last=Chant |first=Christopher |title=The World's Great Bombers: From 1914 to the Present Day |publisher=Amber Books Ltd |year=2005 |isbn=978-0-7858-1989-9 |pages=68}}</ref> When introduced, it was the fastest aircraft in China.

The 139WC was primarily used for [[night bombing]] and [[Maritime reconnaissance aircraft|maritime reconnaissance]].<ref>{{Cite web |last=Cluett |first=Nathan |date=2023-06-23 |title=Martin B-10 - A Leap in Military Aviation |url=https://planehistoria.com/the-martin-b-10/ |access-date=2024-06-17 |website=PlaneHistoria |language=en-US}}</ref>

On 25 August 1937, as the air battles intensified in the early part of the [[Second Sino-Japanese War]],<ref>{{cite web|last=Sun|first=Lianggang|title=Shanghai 1937 – Where World War II Began|url=http://www.shanghai1937.tv/|access-date=2020-11-20|website=SHANGHAI 1937: WHERE WORLD WAR II STARTED|language=en-US}}</ref> five [[Republic of China Air Force|Chinese Nationalist Air Force]] bombers of the [[Development of Chinese Nationalist air force (1937–1945)|8th BG, 19th and 30th Squadrons]] consisting of three [[Heinkel He 111|Heinkel He 111A]]s and two Martin B-10s, flying from their base in [[Nanjing]] to [[Shanghai]], successfully dropped their bombs on Japanese landing forces at [[Liuhe, Taicang]], northwest of Shanghai. However, Japanese aircraft pursued the bombers and shot up two of the Heinkels, forcing them to crash land; two crew members were killed on the ground by Japanese aircraft strafing them.<ref>{{cite web|title=Martyr Chen Xiong-ji|url=https://air.mnd.gov.tw/EN/PastCurrent/PastCurrent_Detail.aspx?FID=28&CID=176&ID=1328|access-date=2020-11-20|website=air.mnd.gov.tw|language=en}}</ref><ref>{{cite web|title=Martyr Yun Feng-zeng|url=https://air.mnd.gov.tw/EN/PastCurrent/PastCurrent_Detail.aspx?FID=28&CID=176&ID=1329|access-date=2020-11-20|website=air.mnd.gov.tw|language=en}}</ref>
[[File:Martin 139WC (B-10) No 1403.jpg|thumb|ROCAF Martin 139WC]]

As the [[National Revolutionary Army]] of China fought desperately to hold onto their remaining positions in the [[Battle of Shanghai]], the Chinese Air Force launched a major strike with a motley mix of aircraft against Japanese positions in Shanghai on 14 October 1937, consisting of three B-10s, two Heinkel He 111As, five [[Douglas O-2]]MCs, five [[Northrop Gamma]]s, and three [[Curtiss BF2C Goshawk|Curtiss Hawk IIIs]] from Nanjing in the late afternoon; in the evening, one bomber was launched every hour from Nanjing to attack Japanese positions in Shanghai until 03:00 on 15 October.

On 19 May 1938, two B-10s of the [[Development of Chinese Nationalist air force (1937–1945)|2nd BG, 14th Squadron]], led by Capt. [[Xu Huansheng|Hsu Huan-sheng]] and Lt. Teng Yen-bo, successfully flew the first air raid on mainland Japan; the unescorted nighttime raid over Japan saw the B-10s dropped 2 million leaflets in "alerting the conscience of the Japanese people against atrocities committed by the Japanese invasion and occupation of China", over the cities of Nagasaki, Fukuoka, Kurume, Saga, and others, while reconnoitering airbases, ports, warships and factories.<ref>Dunn, Richard L. [http://www.warbirdforum.com/elusive.htm "Illusive <sic> Target: Bombing Japan from China."] ''warbirdforum.com'', 2006. Retrieved: 16 May 2013.</ref><ref>[https://books.google.com/books?id=Re8pJnCXvWoC&pg=PA265 Li & Li 1998], p. 265.</ref><ref>[https://books.google.com/books?id=mpSkIrOCrQkC&pg=PA126 Xu 2001], p. 126.</ref><ref>[https://books.google.com/books?id=s2NKutuUlA8C&pg=PA320 Fenby 2009], p. 320.</ref><ref>[https://books.google.com/books?id=N6yy9mXwAEUC&pg=PA86 Underwood 1942], p. 86.</ref>

===Dutch East Indies===
[[File:COLLECTIE TROPENMUSEUM Een Glenn Martin bommenwerper van het KNIL op het militaire vliegveld Andir bij Bandoeng TMnr 60029585.jpg|left|thumb|Dutch Martin 139 at Andir in 1937]]

In the mid-1930s, the Netherlands government adopted a doctrine for defense of the [[Netherlands East Indies]], which relied on the use of land-based bombers against any attacking force, with orders for defensive fighters cancelled to pay for the bomber force. The Martin 139 was chosen in preference to the Dutch [[Fokker T.V]], as its all metal construction was considered more robust than the steel tube and fabric Fokker, while the Martin bomber was also already in production and therefore would be available sooner.<ref name="Casius p1-2">Casius 1983, pp. 1–2.</ref> Twelve Martin 139 WH-1s were ordered for the [[Royal Netherlands East Indies Army Air Force]] (ML-KNIL) in 1936, followed by 26 improved WH-2s in March 1937, sufficient bombers to equip a Group of three squadrons.<ref name="Casius p2">Casius 1983, p. 2.</ref> In December 1937, an order was placed for 39 Martin 139 WH-3s, followed by an order for 40 Martin 139 WH-3As in November 1938. Two more Martin 139 WH-3As were ordered in July 1939 to replace aircraft lost during delivery. The last of these attrition replacement aircraft was delivered in March 1940, including the last Martin B-10/139 built.<ref name="Casius p3">Casius 1983, p. 3</ref> On the outbreak of war with Japan in December 1941, about 58 Martins (WH-3 and WH-3As) were operational with six squadrons, with about 20 more of the older variants in reserve.<ref>Shores, Cull & Izawa 1992, pp. 59–60</ref> B-10s of the ML-KNIL served in the [[Dutch East Indies campaign|defense of the Dutch East Indies]].

During the start of [[Pacific War]], Dutch Martin units were as follows:<ref name="Oktorinop42">Oktorino 2019, pp. 42</ref>
*''Ie Vliegtuiggroep'' (VLG-I) based on [[Husein Sastranegara International Airport|Andir Airfield]], [[Bandung|Bandoeng]] which consisted of ''1e Afdeling'' (1-VLG-I) and ''2e Afdeling'' (2-VLG-I), each has nine Martin 139WH-3/3A with additional two aircraft as reserve. Each ''afdeling'' has a detachment during the war, with the ''Patrouille'' Butner of 1-VLG-I stationed at [[Juwata International Airport|Tarakan]] and ''Patrouille'' Cooke of 2-VLG-I stationed at [[West Kutai Melalan Airport|Samarinda II Airfield]], [[West Kutai Regency|Melak]].
*''IIe Vliegtuiggroep'' (VLG-II) based on [[Abdul Rachman Saleh Airport|Singosari Airfield]], [[Malang]] which consisted of ''1e Afdeling'' (1-VLG-II) with nine WH-3/3A with three additional reserves and three WH-2. During the war, four ''patrouille'' consisted of three aircraft plus a reserve were created from 1-VLG-II, with the crews mobilized from [[Suryadarma Air Force Base|Kalidjati]] flight school.
*''IIIe Vliegtuiggroep'' (VLG-III) based on [[Halim Perdanakusuma International Airport|Tjililitan Airfield]], [[Batavia, Dutch East Indies|Batavia]] which consisted of ''1e Afdeling'' (1-VLG-III) and ''3e Afdeling'' (3-VLG-III), each equipped with nine WH-3/3A with two additional reserves, and ''2e Afdeling'' (2-VLG-III) with nine WH-2 with two additional reserves. ''7e Afdeling Bommenwerpers'', a reserve unit mobilized on 15 December 1941, were placed under VLG-III and consisted of one WH-2, two WH-3 and six WH-3A.
[[File:AWM 011293.jpg|thumb|Dutch Martin Model 166 over Malaya in January 1942]]

In efforts to reinforce the British defense of the Malay Peninsula, the Dutch East Indies sent some ML-KNIL squadrons. Included were 22 Martin 139s from VLG-III that were organized into three squadrons, which arrived at Singapore on 9 December 1941. Due to a lack of coordination, British AA mistook the Dutch Martins for enemy aircraft and engaged them as they neared Singapore. The Martins were then stationed at [[Sembawang Air Base|Sembawang]].<ref>Oktorino 2019, pp. 82–83</ref> In early January 1942, Dutch Martins along with British [[Bristol Blenheim|Blenheim]] bombers sortied over the west coast of Malaya to halt the Japanese advance.<ref>Oktorino 2019, pp. 84–85</ref> On 8 January, nine Martin and four Australian [[Lockheed Hudson|Hudson]] attacked a suspected Japanese seaplane tender anchored offshore in South China Sea, but the results were inconclusive. In the next day, nine Martin "quite successfully" bombed several Japanese ships unloading cargo at [[Kuantan]].<ref>Oktorino 2019, pp. 93 & 96</ref> Two Martins were shot down by the Japanese near [[Penang]] on 1 January, while a further four Martins were lost while attacking Japanese forces on the [[Muar River]] on 19 January. On the same day, Dutch fighter squadrons were withdrawn to Sumatra, while the Martins were also withdrawn to Java three days later.<ref>Oktorino 2019, pp. 99</ref>

===Thailand===
Six B-10s formed the medium bomber force of the [[Royal Thai Air Force#History|Royal Thai Air Force]] at the start of the 1940–1941 [[Franco-Thai War]].<ref name="Young p23"/> They flew several bombing missions during the war, with their first mission against [[Khoune district|Xieng Khuang]], [[Laos]] and a nearby airfield on 15 December 1940,<ref name="Youngp278">Young 1984, pp. 27–28</ref> with the last mission, against [[Serei Saophoan (city)|Sisophon]] in what is now Cambodia on 28 January at the very end of the Franco-Thai War.<ref name="Youngp33">Young 1984, p. 33</ref> Later on, B-10s had been assigned to the airfield in Phrae as a part of Phayap Army to invade Shan state.<ref>{{cite web|url=https://www.finearts.go.th/chiangmailibrary/view/7088-%E0%B9%80%E0%B8%8A%E0%B8%B5%E0%B8%A2%E0%B8%87%E0%B9%83%E0%B8%AB%E0%B8%A1%E0%B9%88%E0%B8%81%E0%B8%B1%E0%B8%9A%E0%B8%A0%E0%B8%B1%E0%B8%A2%E0%B8%97%E0%B8%B2%E0%B8%87%E0%B8%AD%E0%B8%B2%E0%B8%81%E0%B8%B2%E0%B8%A8|script-title=th:เชียงใหม่กับภัยทางอากาศ|language=th|work=[[National Library of Chiang Mai]]|access-date=2023-06-23}}</ref>

=== Turkey ===
After being delivered in September 1937, the Martin 139WTs were assigned to the 55th and 56th Tayyare Bölüğü (Aviation Squadrons) of the 9th Tayyare Taburu (Aviation Battalion).<ref name=":0">{{Cite web|title=MARTIN 139 WT B10 .. 1923 - 1950 Period TUAF {{sic|nolink=yes|AIRCRAFTS}} 1923 -1950 dönemi Turk HvKK UCAKLARI|url=http://www.tayyareci.com/digerucaklar/turkiye/1923ve50/martin139wt.asp|access-date=2023-01-07|website=www.tayyareci.com|archive-date=7 January 2023|archive-url=https://web.archive.org/web/20230107110746/http://www.tayyareci.com/digerucaklar/turkiye/1923ve50/martin139wt.asp|url-status=dead}}</ref> During the [[World War II|Second World War]], the aircraft were extensively deployed for surveillance over the [[Black Sea]].<ref>{{cite web|last=Oryx|title=From Martin 139 To Kızılelma: 85 Years Of Turkish Bombers|url=https://www.oryxspioenkop.com/2023/01/from-martin-139-to-kzlelma-85-years-of.html|access-date=2023-01-07|website=Oryx}}</ref> After being replaced by British Blenheims and Beauforts in 1944, the Martin 139WTs served as backup aircraft until 1946, when twelve of the sixteen remaining aircraft were still operational.<ref name=":0" />

==Legacy==
At the time of its creation, the B-10B was so advanced that General [[Henry H. Arnold]] described it as the airpower wonder of its day. It was half again as fast as any biplane bomber, and faster than any contemporary fighter. The B-10 began a revolution in bomber design, making existing bombers completely obsolete.<ref name="fitz46"/>

Rapid advances in bomber design in the late 1930s meant that the B-10 was eclipsed by the time the United States entered [[World War II]]. The Model 139s in combat in China and South East Asia suffered the same disadvantages as the other early war medium bombers, i.e. not enough armor and guns, while it could not outrun the latest fighters.

An abortive effort to modernize the design, the [[Martin Model 146]], was entered into a USAAC long-distance bomber design competition in 1934–5. The bomber came in a strong second place and was bested by only the [[Boeing B-17 Flying Fortress|Boeing B-17]] in range and endurance. However, it had a higher ceiling of {{cvt|28500|ft|m}}, was only {{cvt|2|mph|kph|0}} slower, and carried {{cvt|313|lb|kg}} less in bombs than the Boeing, at over half the cost. Nonetheless, the design was seen as a dead end, and the third-place contender, the [[Douglas B-18 Bolo|Douglas B-18]], was selected instead.<ref>David D Gravermoen ''B-10 - The Martin Bomber''</ref>

==Variants==
[[File:Martin XB-907 in flight.jpg|thumb|Martin XB-907]]
[[File:Martin YB-10.jpg|thumb|Martin YB-10]]
[[File:Martin B-12 parked.jpg|thumb|Martin B-12]]
[[File:Martin B-12A.jpg|thumb|Martin B-12A]]
[[File:Martin XB-14.jpg|thumb|Martin XB-14]]

=== Martin Model 123 ===
Private venture of Martin company, predecessor of the XB-10, served as prototype for the series, one built.<ref name="fitz45">Fitzsimons 1967/1969, p. 1845.</ref>
;XB-907
:US Army designation for the Model 123 in evaluation,<ref name="fitz45"/> with open cockpits and two Wright SR-1820-E, delivered April 1932.
;XB-907A
:Modified XB-907 after Martin returned it to U.S. Army for further operational trials,<ref name="fitz46"/> with larger wingspan and two Wright R-1820-19.
;XB-10
:Designation of the prototype when purchased by the United States Army Air Corps; modified XB-907A with enclosed cockpits and turret and single strut landing gear.<ref name="world1"/><ref>{{cite web | url = http://www.10af.afrc.af.mil/shared/media/photodb/photos/060511-F-1234S-003.jpg | title = Photo of XB-10 | archiveurl=https://web.archive.org/web/20110722180510/http://www.10af.afrc.af.mil/shared/media/photodb/photos/060511-F-1234S-003.jpg| archivedate=2011-07-22 | work = US Air Force }}</ref>

=== Martin Model 139, 139A and 139B ===
Army Air Corps versions, 165 built.
;YB-10
:Model 139A, test and production version of the XB-10 with crew reduced to three members, and two {{cvt|675|hp|kW}} R-1820-25, 14 built, some flown temporarily as float planes.<ref name="world2"/>
;YB-10A
:The '''YB-10A''' was different from a YB-10 only in its engines. It used [[Wright R-1820]]-31 turbo-supercharged radials, allowing it to attain speeds of {{cvt|236|mph|kph}}. This made it the fastest aircraft of the B-10 series. Despite this advantage, only one was built, as a test aircraft.<ref name="world2"/>
;B-10
:According to one source, two additional aircraft ordered in 1936.<ref name="world2"/>
;B-10B
:Model 139, main production version with two {{cvt|775|hp|kW}} R-1820-33 engines, 105 built, delivered August 1936.<ref name="world2"/>
;B-10M
:According to one source this was, these were B-10Bs converted as target tugs.<ref name="world2"/> According to Martin's own archive, this was the designation of the YB-10 after testing, then used for airmail and Alaska missions, 13 of the 14 built were still in service in April 1940.
;RB-10MA
:One former NEIAF Model 139WH-3A model impressed in July 1942 and flown from Australia to the United States.<ref name="world2"/>
;YB-12
:Model 139B. With {{convert|250|or|500|USgal|L}} flotation chambers for safety on overwater flights, and two [[Pratt & Whitney R-1690]]-11 "Hornet" radial engines. These {{cvt|775|hp|kW}} engines gave similar performance to those on the B-10B ({{cvt|218|mph|kph}}), seven built, five still in service in April 1940.<ref name="world2"/>
;(Y)B-12A
:The production version of the YB-12 with provision for a {{cvt|365|USgal|L}} fuel tank in the bomb bay, giving the B-12A a combat range of {{cvt|1240|mi|km}}, 25 built, 23 still in service in April 1940.<ref name="world2"/>
;YB-13
:Re-engined version of the YB-10 powered by two {{cvt|700|hp|kW}} [[Pratt & Whitney R-1860|Pratt & Whitney R-1860-17 Hornet B]] radial engines. Ten were on order but cancelled before production started, not built.<ref name="world2"/>
;XB-14
:To test the new {{cvt|900|hp|kW}} [[Pratt & Whitney R-1830|Pratt & Whitney YR-1830-9]] "Twin Wasp" radial engines, one built which was converted back to YB-12 after testing.<ref name="world2"/>
;A-15
:Proposed attack variant of the YB-10 with two {{cvt|750|hp|kW}} R-1820-25 engines, was never built. The contract fell to the [[A-14 Shrike]].<ref name="ohnine2">Swanborough and Bowers 1964, p. 332.</ref>
;YO-45
:With two {{cvt|750|hp|kW}} Wright R-1820-17, proposed high-speed observation role, one B-10 was beginning to be converted in 1934 and another in 1935 but both were stopped before being completed and were converted back into B-10s.

=== Model 139W and 166 ===
The export versions, 100 built (182 including the Model 166, see below).
;Model 139WA
:Martin demonstrator for Argentina, later sold to Argentine Navy.
;Model 139WAA
:Export version for Argentine Army, 22 built, delivered April 1938.
;Model 139WAN
:Export version for the Argentine Navy, 12 built, delivered November 1937.
;Model 139WC and WC-2
:Export version for China, six and three built, delivered in February and August 1937.<ref name="jackson"/><ref name="Baugher">Baugher, Joe. [http://www.joebaugher.com/usaf_bombers/b10.html "Martin B-10".] ''American Military Aircraft'', 11 July 1999. Retrieved: 13 June 2010.</ref>
;Model 139WH
:Export version for the Netherlands, used in the Netherlands East Indies. Thirteen WH-1s, powered by {{convert|770|hp|kW|abbr=on}} Cyclone GR-1820-F53 engines delivered from December 1936, followed by 26 WH-2s, with {{convert|875|hp|kW|abbr=on}} GR-1820-G3 engines, delivered 1938.<ref name="Casius p23,6">Casius 1983, pp. 2–3, 6.</ref>
;Model 139WR
:Single demonstrator to the Soviet Union.<ref name="world2"/><ref name="Baugher"/>
;Model 139WSM and WSM-2
:Export version for Siam, three and three built, delivered in March and April 1937.<ref name="world2"/>  Locally designated B.Th.3 ({{langx|th|บ.ท.๓}}).<ref>{{Cite web |title=Thai Military Aircraft Designations |url=https://designation-systems.net/non-us/thailand.html |access-date=2025-03-18 |website=designation-systems.net}}</ref>
;Model 139WSP
:Proposed license built version to be built by CASA of Spain, production blocked by U.S. State Department.
;Model 139WT
:Export version for Turkey, 20 built, delivered September 1937.<ref name="jackson"/>
 
[[File:Dutch Martin Model 166.jpg|thumb|Side view of Dutch Martin Model 166]]
;Model 166
Final version, a.k.a. 139WH-3 and 139WH-3A, 82 built.
:Export version for the Netherlands, used in the Netherlands East Indies. Redesigned wings, nose and single 'glass house' canopy, bomb shackles between engines and fuselage, and better engines. The WH-3 had two {{cvt|900|hp|kW}} R-1820-G5 (40 built, delivered September 1938), the WH-3A had two {{cvt|1000|hp|kW}} R-1820-G-105A (42 built, delivered March 1940). With the bomb shackles, the bomb load could be doubled for a shorter range. A total of 121 of all types were built for the Dutch.<ref name="world2"/>

==Operators==
;{{ARG}}
*[[Army Aviation Service]] received 22 Model 139WAA aircraft,<ref>{{cite web|url=http://www.gacetaeronautica.com/gaceta/wp-101/?p=5991|title=Catálogo Ilustrado de Aeronaves de la Fuerza Aérea Argentina|last1=Ay|first1=Carlos|language=es|date=2013-08-15|website=Gaceta Aeronautica|access-date=2014-05-31}}</ref> plus 1 fuselage for training.
*[[Argentine Navy]] – The [[Argentine Naval Aviation]] received 12 Model 139WAN and 1 Model 139WA aircraft.<ref>[http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=3366 "Donation of the Martin B-10."] {{webarchive|url=https://web.archive.org/web/20071026102426/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=3366|date=2007-10-26}} ''National Museum of the United States Air Force''. Retrieved: 13 June 2010.</ref>
;{{Flagcountry|Nationalist government}}
*[[Chinese Nationalist Air Force]] ordered nine Martin 139s (six Model 139WC-1 and three Model 139WC-2), which were delivered in 1936 and 1937.<ref>Andersson 2008, p. 275</ref><ref>{{cite web|url=http://cwlam2000.0catch.com/caf30.htm|title=Photos as well as paintings of ROC|access-date=2013-06-13|archive-date=2013-10-20|archive-url=https://web.archive.org/web/20131020064937/http://cwlam2000.0catch.com/caf30.htm|url-status=dead}}</ref>
;{{flag|The Netherlands}}
*[[Royal Netherlands East Indies Army Air Force]]
;{{Flag|Philippine Commonwealth|1936}}
*[[Philippine Army Air Corps]]<ref>Shores, Cull and Izawa 1992, pp. 38, 56.</ref>
;{{Flagicon|Thailand}} [[Thailand]]
*[[Royal Thai Air Force]] received six Model 139W aircraft in April 1937 and used them during the [[French-Thai War]] of 1940–41,<ref name="Young p23">Young 1984, p. 23.</ref> and during the 1942 [[Burma Campaign#Thai army enters Burma|invasion of Burma]]. It was given a further nine ex-Dutch aircraft by the Japanese in 1942. They remained in service until 1949.<ref name="Casius p20">Casius 1983, p. 20.</ref>
;{{TUR}}
*[[Turkish Air Force]] received 20 Model 139W aircraft in September 1937.
;{{USSR}}
*[[Soviet Air Force]] bought one aircraft for evaluation.
;{{flag|United States|1912}}
*[[United States Army Air Corps]]

==Surviving aircraft==
[[File:Martin YB-10 NMUSAF GVG.jpg|thumb|Ex-Argentine model 139WAA at the [[National Museum of the United States Air Force]] painted as a USAAC B-10]]

*The only surviving complete example is on display at the [[National Museum of the United States Air Force]] at [[Wright-Patterson Air Force Base]] near [[Dayton, Ohio]]. The aircraft is painted as a B-10 used in the 1934 Alaskan Flight but was a Martin 139WAA export version sold to [[Argentina]] in 1938. The aircraft was restored by the 96th Maintenance Squadron (Mobile), [[Air Force Reserve]], at [[Kelly Air Force Base]], Texas, in 1973–1976, and placed on display in 1976.<ref name="Fact Sheet">[http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=3366 "USAF Fact Sheet Martin B-10."] {{webarchive|url=https://web.archive.org/web/20071026102426/http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=3366|date=2007-10-26}} ''National Museum of the United States Air Force''. Retrieved 13 June 2010.</ref>
*The wreck of a crashed Dutch Martin 166WH-3 in [[East Kalimantan]], [[Indonesia]] was rediscovered during an expedition by local newspaper ''Berau Post'' in early August 2018, based on local villagers' story of a crashed aircraft on top of a mountain. The wreck is located on Gunung Besar, Long Keluh Village, Kelay District, [[Berau Regency]].<ref>Coordinates {{coord|1|52|38.5|N|116|52|24.3|E}}</ref> Large parts of the wreck, such as the two engines, mid and rear fuselage, tail and elevators, and the right wing are still extant at the time of the expedition. According to a local villager, parts of the wreck have been looted by locals for decades. The aircraft's number, "M-574", was still visible amidst the moss in the wreck.<ref>{{cite web|last1=Co |first1=Prokal |url=https://berau.prokal.co/read/news/56681-nama-diambil-dari-pesawat-yang-jatuh|title=Menguak Misteri Gunung Pesawat: Nama Diambil dari Pesawat yang Jatuh|website=berau.prokal.co|date=2018-08-17|access-date=2022-09-26|language=ID}}</ref><ref>{{cite web|last1=Co |first1=Prokal |url=https://berau.prokal.co/read/news/56682-pesawat-di-gunung-itu-diduga-martin-b-10|title=Pesawat di Gunung Itu Diduga Martin B-10|website=berau.prokal.co|date=2018-08-17|access-date=2022-09-26|language=ID}}</ref><ref>{{cite web|url=http://tintakaltim.com/misteri-gunung-pesawat-di-kabupaten-berau/|title=Misteri Gunung Pesawat di Kabupaten Berau|website=tintakaltim.com|date=2019-03-26|access-date=2022-09-26|language=ID}}</ref> The "M-574" was reported missing during a mission over southeast Dutch Borneo on 5 January 1941.<ref>{{cite web|url=https://aviation-safety.net/wikibase/221262 |title=Accident Martin 166 WH-3 M-574, 05 Jan 1941|website=aviation-safety.net|access-date=2022-09-26}}</ref>
*Various parts of crashed B-10s, such as [[gun turret|turrets]] and [[wing]]s, were retrieved from the [[jungle]] of [[Borneo]] and were on display in the [[Militaire Luchtvaart Museum]] (Military Aviation Museum) at [[Soesterberg]], the [[Netherlands]].<ref>[http://www.militaireluchtvaartmuseum.nl/ "Martin B-10" (in Dutch).] {{webarchive|url=https://web.archive.org/web/20101023013200/http://www.militaireluchtvaartmuseum.nl/|date=2010-10-23}} ''Netherlands Military Aviation Museum''. Retrieved 22 December 2010.</ref> Since the closure of the MLM, they are stored with the [[Nationaal Militair Museum]], located on the former [[Soesterberg Air Base]].

==Specifications (B-10B)==
[[File:Martin B-10 3-view silhouette.png|thumb|3-view silhouette of the Martin B-10]]

{{Aircraft specs
|ref=''United States Military Aircraft Since 1909.''<ref name="ohnine3">Swanborough and Bowers, 1964, p. 333.</ref>
|prime units?=imp
<!--
        General characteristics
-->
|crew=4
|length ft=44
|length in=9
|length note=
|span ft=70
|span in=6
|span note=
|height ft=15
|height in=5
|height note=
|wing area sqft=678
|wing area note=
|aspect ratio=<!-- sailplanes -->
|airfoil=<!--'''root:''' [[NACA airfoil|NACA ]]; '''tip:''' [[NACA airfoil|NACA ]]<ref name="Selig">{{cite web|last1=Lednicer|first1=David|title=The Incomplete Guide to Airfoil Usage|url=https://m-selig.ae.illinois.edu/ads/aircraft.html|website=m-selig.ae.illinois.edu|access-date=2019-04-16}}</ref>-->
|empty weight lb=9681
|empty weight note=
|gross weight lb=14700
|gross weight note=
|max takeoff weight lb=16400
|max takeoff weight note=
|fuel capacity=
|more general=
<!--
        Powerplant
-->
|eng1 number=2
|eng1 name=[[Wright R-1820-33 Cyclone]] (F-3)
|eng1 type=9-cylinder air-cooled radial piston engines
|eng1 hp=775
|eng1 note=

|prop blade number=3
|prop name=variable-pitch propellers
|prop dia ft=<!-- propeller aircraft -->
|prop dia in=<!-- propeller aircraft -->
|prop dia note=
<!--
        Performance
-->
|max speed mph=213
|max speed note=
|cruise speed mph=193
|cruise speed note=
|stall speed mph=
|stall speed note=
|never exceed speed mph=
|never exceed speed note=
|minimum control speed mph=
|minimum control speed note=
|range miles=1240
|range note=
|combat range miles=
|combat range note=
|ferry range miles=
|ferry range note=
|endurance=<!-- if range unknown -->
|ceiling ft=24200
|ceiling note=
|climb rate ftmin=
|climb rate note=
|time to altitude=
|wing loading lb/sqft=21.7
|wing loading note=
|fuel consumption lb/mi=
|power/mass={{cvt|0.105|hp/lb|abbr=on}}

|more performance=<!--<br />
*'''Take-off run:''' {{cvt||ft|0}}
*'''Take-off distance to {{cvt|50|ft|0}}:''' {{cvt||ft|0}}
*'''Landing run:''' {{cvt||ft|0}}
*'''Landing distance from {{cvt|50|ft|0}}:''' {{cvt||ft|0}}-->
<!--
        Armament
-->
|guns=3 × {{cvt|0.300|in|2}} [[M1919 Browning machine gun|Browning machine gun]]s
|bombs={{cvt|2260|lb|0}}
}}

==See also==
{{Aircontent
|similar aircraft=
* [[Boeing Y1B-9]]
* [[Tupolev SB]]
|lists=
* [[List of bomber aircraft]]
* [[List of military aircraft of the United States]]
* [[List of aircraft of World War II]]
}}

==References==
{{Reflist|30em}}

==Sources==
* {{cite book |last=Andersson |first=Lennart |title=Encyclopedia of Aircraft and Aviation in China until 1949 |year=2008 |location=Taipei, ROC |publisher=AHS of ROC |isbn=978-957-28533-3-7}}
* Bridgwater, H.C. and Peter Scott. ''Combat Colours Number 4: Pearl Harbor and Beyond, December 1941 to May 1942''. Luton, Bedfordshire, UK: Guideline Publications, 2001. {{ISBN|0-9539040-6-7}}.
* Casius, Gerald. "Batavia's Big Sticks." ''[[Air Enthusiast]]'', Issue Twenty-two, August–November 1983, pp.&nbsp;1–20. Bromley, Kent, UK: Pilot Press Ltd, 1983. {{ISSN|0143-5450}}.
* "Collier Trophy Is Presented to Martin By Roosevelt for New Airplane Design." ''New York Times'', 1 June 1933.
* Eden, Paul and Soph Moeng, eds. ''The Complete Encyclopedia of World Aircraft''. London: Amber Books Ltd., 2002. {{ISBN|0-7607-3432-1}}.
*{{cite book|title=Chiang Kai Shek: China's Generalissimo and the Nation He Lost|first=Jonathan|last=Fenby|year=2009|publisher=Da Capo Press|url=https://books.google.com/books?id=s2NKutuUlA8C|isbn=978-0786739844}}
* Fitzsimons, Bernard, ed. ''The Illustrated Encyclopedia of the 20th Century Weapons and Warfare''. New York: Purnell & Sons Ltd., 1969, First edition 1967. {{ISBN|0-8393-6175-0}}.
* Glenn L. Martin Aviation Museum. ''Martin Aircraft Specifications''.
* Gravermoen, David D. ''B-10 - The Martin Bomber''. Spartanburg: Dakar Publishing {{ISBN|978-0996993203}}.
* Jackson, Robert. ''The Encyclopedia of Military Aircraft''. London: Parragon Publishing, 2003. {{ISBN|1-4054-2465-6}}.
*{{cite journal |last1=Ledet|first1=Michel|title=Des avions alliés aux couleurs japonais |journal=Avions: Toute l'Aéronautique et son histoire |date=April 2002 |issue=109 |pages=17–21 |trans-title=Allied Aircraft in Japanese Colors|language=fr |issn=1243-8650}}
*{{cite journal |last1=Ledet|first1=Michel|title=Des avions alliés aux couleurs japonais |journal= Avions: Toute l'Aéronautique et son histoire |date=May 2002 |issue=110 |pages=16–23|language=fr |issn=1243-8650}}
*{{cite book|title=China and the United States: A New Cold War History|editor1-first=Xiaobing|editor1-last=Li|editor2-first=Hongshan|editor2-last=Li|year=1998|publisher=University Press of America|isbn=9780761809784 |url=https://books.google.com/books?id=Re8pJnCXvWoC}}
*{{cite book|title=Duel Para Elang - Pertempuran Udara di Atas Hindia Belanda|first=Nino|last=Oktorino|year=2019|publisher=PT Elex Media Komputindo|location=Jakarta|language=ID|isbn= 9786230000997}}
* Shores, Christopher; Cull, Brian and Yasuho Izawa. ''Bloody Shambles: Volume One: The Drift to War to the Fall of Singapore''. London: Grub Street, 1992. {{ISBN|0-948817-50-X}}
* Swanborough, F. Gordon and Peter M. Bowers. ''United States Military Aircraft Since 1909''. New York: Putnam, 1964. {{ISBN|0-85177-816-X}}.
* Taylor, John W. R. "Martin B-10". ''Combat Aircraft of the World from 1909 to the Present''. New York: G.P. Putnam's Sons, 1969. {{ISBN|0-425-03633-2}}.
*{{cite book |title=War Wings: The United States and Chinese Military Aviation, 1929–1949 |first=Guangqiu |last=Xu |isbn=9780313320040 |year=2001 |publisher=Greenwood Press |url=https://books.google.com/books?id=mpSkIrOCrQkC}}
*{{cite magazine |last=Underwood |first=J. Barton |date=Nov 1941 |volume=29 |number=5 |title=America Plays Its Part in the Chinese Air Force |url=https://books.google.com/books?id=N6yy9mXwAEUC&pg=PA86 |magazine=Flying and Popular Aviation |issn=0015-4806}}
* Young, Edward M. "France's Forgotten Air War". ''[[Air Enthusiast]]'' Issue Twenty Five, August–November 1984, pp.&nbsp;22–33. Bromley, Kent: Pilot Press. {{ISSN|0143-5450}}.

== Further reading ==
*{{Cite book |last1=Núñez Padin |first1=Jorge Felix |last2=Benedetto |first2=Fernando C. |title=Martin 139W en Argentina |year=2007 |editor-first=Jorge Felix |editor-last=Núñez Padin |publisher=Fuerzas Aeronavales |series=Serie en Argentina |volume=Nº1 |language=es |location=Buenos Aires, Argentina |url=http://www.fuerzasaeronavales.com/?product=libro-martin-139w-en-argentina-serie-en-argentina-no1 |access-date=29 July 2016 |url-status=dead|archive-url=https://web.archive.org/web/20160313121936/http://www.fuerzasaeronavales.com/?product=libro-martin-139w-en-argentina-serie-en-argentina-no1 |archive-date=13 March 2016  }}

==External links==
{{Commons category|Martin B-10}}
* [https://www.nationalmuseum.af.mil/Visit/Museum-Exhibits/Fact-Sheets/Display/Article/197393/martin-b-10/ National Museum of the U.S. Air Force fact sheet on the Martin B-10]
* [http://www.americancombatplanes.com/martin_bmrs_2.html Martin Bombers ~ American Combat Planes of the 20th Century by Ray Wagner] {{Webarchive|url=https://web.archive.org/web/20120227111941/http://www.americancombatplanes.com/martin_bmrs_2.html |date=27 February 2012 }}
* [https://books.google.com/books?id=uN4DAAAAMBAJ&pg=PA888 "Phantom Raiders of the Air" ''Popular Mechanics'', June 1935, pp. 888–889, cutaway drawing in flight showing crew stations]
* {{Internet Archive short film|id=gov.dod.dimoc.52240|name=15 AF HERITAGE – HIGH STRATEGY – BOMBER AND TANKERS TEAM (1980)}}

{{Martin aircraft}}
{{AircraftDesignationNavboxShell
  |1={{USAF attack aircraft}}
  |2={{USAF bomber aircraft}}
  |3={{USAAF observation aircraft}}
  |4={{Wright Field project numbers}}
  |5={{Thai bomber designations}}
  }}
{{Authority control}}

[[Category:1930s United States bomber aircraft|Martin B-10]]
[[Category:Martin aircraft|B-10]]
[[Category:Aircraft first flown in 1932]]
[[Category:Mid-wing aircraft]]
[[Category:Twin piston-engined tractor aircraft]]
[[Category:Aircraft with retractable conventional landing gear]]