Export Versions
With such an advanced performance, the Martin company fully expected that export orders for the
B-10 would come flooding in. However, since the Army owned the rights to the Model 139 design,
it forbade any export overseas until its own orders had been filled. However, following the
completion of the last example for the Army in 1936, clearance was finally given for the export
of the Martin bomber.
The first export demonstrator, the Model 139W, was completed in August of 1936. It was powered
by a pair of 750 hp Wright R-1820-F53 Cyclones. The civilian registration number NR-15563 was
applied. It was sent to Argentina in September to compete against the German Junkers JU-86 and
the Italian Savoia SM-79B for Argentine orders. The Martin plane won the contract, and Argentina
ordered 13 examples for the Navy and 26 for the Army.
Other export orders soon followed. The Martin 139WC was a version intended for China. It was
powered by a pair of 850 hp R-1820-G2 Cyclones. 6 examples went to China in February of 1937.
They were used in combat when Japan invaded China in August of 1937. These Martin 139WCs were
the first American-designed bombers to see combat. However, the results were not all that good,
since most were destroyed on the ground during Japanese air attacks.
Six Martins were sold to Siam in April of 1937. They were powered by R-1820-G3 Cyclones. 20
Model 139Ws were sold to Turkey in September of 1937, powered by R-1820-G2 engines
A single Model 139WR (X16706) was sold to the Soviet Union for evaluation. Its fate is unknown.
Plans to sell Martin 139s to Republican Spain were blocked by the State Department. Reports that
the Martin bomber was being used in Spain on the Republican side were in error, being
misidentifications of the Soviet Tupolev SB-2, which was basically similar in overall configuration.
The largest customer for the export Martin bomber was the Dutch East Indies. The first Dutch
order was for 12 Model 139WH-1 bombers powered by 750 hp R-1820-F53 Cyclones. They were delivered
between September 1936 and February 1937. 26 Model 139WH-3s, powered by 840 hp R-1820-G3s were
delivered from November 1937 to March 1938. The final export version was the Model 139WH-3
(or Model 166), powered by a pair of 900 hp Wright R-1820G-102 radials. It had a long unbroken
transparent canopy "greenhouse" that extended from the pilot's cockpit all the way to the rear
gunner's position. 78 of these new bombers were delivered by May 5, 1939, when the last export
Martin bomber rolled off the Baltimore production line.
Between mid-1936 and 1939, a total of 189 export Model 139W and Model 166 bombers had been
manufactured.
Six squadrons of Martin bombers were serving in the Dutch East Indies when the Japanese invaded.
Dutch crews flew these Martin bombers in a futile attempt to stem the Japanese advance into the
Dutch East Indies during early 1942. By this time, the Martin bomber was thoroughly obsolete,
and its speed and armament were completely inadequate to protect against the fast and heavily-armed Japanese Zero fighters. Most were shot down in combat or were destroyed on the ground.
A surviving export Model 139 fled from the Dutch East Indies to Australia on March 7, 1942.
It was taken on strength by the USAAF for use as an utility aircraft and assigned the serial
number 42-68358. This was the only export Martin 139 to serve with the USAAF.
An Argentine Martin Model 139 was returned to the USA in 1976. It was refurbished as a standard
USAAC B-10B and is now on display in the Air Force Museum at Wright-Patterson AFB in Ohio.
So far as I am aware, it is the only surviving Model 139 bomber.
Two Wright R-1820-33 Cyclone air-cooled radial engines, rated at 775 hp for takeoff and 750 hp
at 5400 feet. Maximum speed 213 mph at 10,000 feet, 196 mph at sea level. An altitude of 5000 feet
could be attained in 3.4 minutes. Cruising speed 193 mph. Landing speed 65 mph. Service ceiling
14,200 feet. Normal range 590 miles, maximum range 1240 miles, ferry range 1830 miles.
Weights: 9681 pounds empty, 14,600 pounds gross, 16,400 pounds maximum.
One 0.30-inch Browning machine gun in nose turret,
one 0.30-inch Browning machine gun in flexible mount in dorsal gunner position,
one 0.30-inch Browning machine gun in a ventral tunnel position mounted in the
floor of the fuselage behind the bomb bay. 2260 pounds of bombs could be carried.
