Martin B-10
| Martin B-10 | |
|---|---|
 A USAAC B-10B |
|
| Type: | bomber |
| Design country: | |
| Manufacturer: | |
| First flight: |
February 16, 1932 |
| Commissioning: |
November 1934 |
| Production time: |
1933 to 1936 |
| Number of pieces: |
342 |
The Martin B-10 was an American all-metal bomber in monoplane design . The machines entered service with the United States Army Air Corps (USAAC) in 1934 . It was the first mass-produced bomber whose performance was comparable to that of the fighter planes of the time.
The B-10 served under the designations B-12 , B-13 , B-14 and A-15 .
construction
A revolution in bomber design began with the B-10 . In addition to the all-metal fuselage and the design as a monoplane, many innovations were incorporated into the B-10, which later became standard in bomber construction. It had a rotating gun turret, retractable landing gear, internal bomb bay and fully faired engines. The crew consisted of four men, the pilot, copilot, a gunner in the aircraft nose and a gunner in the fuselage.
The aircraft was powered by two 600 hp (447 kW) Wright SR-1820 E Cyclone radial engines.
history
The development of the XB-10 began as Martin Model 123 in a private financing by the Glenn L. Martin Company in Baltimore . The first flight took place on February 16, 1932 and the test delivery to the US Army on March 20 of the same year.
The XB-10 delivered to the US Army had, in contrast to the 123 model , fully faired engines and was aerodynamically better built. In addition, a turret was built into the aircraft nose and the wingspan was slightly increased. Test flights in June 1932 achieved a speed of 317 km / h at an altitude of 1,830 m - an impressive achievement at the time.
After the success of the XB-10 , minor changes were made and the crew reduced to three men. The engine output was increased to 675 hp (503 kW). On January 17, 1933, the US Army ordered 48 machines.
The first 14 machines were named YB-10 (Martin Model 139) and were delivered to Wright Field in November 1933. The YB-10 was still very similar to the XB-10 :
After deliveries to the US Army were completed, Martin received an export license for the Model 139 in 1936. The machines were shipped to Argentina , China , the Netherlands , Dutch East Indies , Thailand , the Soviet Union (a test machine), and Turkey .
During World War II they were only used briefly in the Dutch East Indies and China , but had to be withdrawn because of the superiority of the Japanese Mitsubishi Zero .
An Argentine YB-10 returned to the United States in 1976 and is now in the USAF Museum at Wright-Patterson Air Force Base in Dayton, Ohio . A number of B-10 parts from the Borneo jungle can now be found in the Militaire Luchtvaart Museum in Soesterberg in the Netherlands .
The only difference between the YB-10A and the YB-10 was the engine. It had Wright R-1820-31 turbocharged radial engines that allowed it a speed of 380 km / h. It was the fastest B-10 variant, but there was only one prototype.
In 1935 the US Army ordered 103 additional machines with the designation B-10B , which practically resembled the YB-10 type. The B-10B came in the following units: 2nd Bomb Group in Langley Field , 9th Bomb Group in Mitchel Field, 19th Bomb Group in March Field, 6th Bomb Group in the Panama Canal Zone, and the 28th Bomb Group in the Philippines .
The rapid development of bombers in the 1930s finally led to the replacement of the B-10 by the B-17 Flying Fortress and the Douglas B-18 Bolo before the USA entered the war at the end of 1941. General Henry H. Arnold described the B-10 as a miracle in flight its time. It was one and a half times faster than any existing bomber and faster than the fighters of its time.
B-12
Of the 48 XB-10s ordered, 7 were converted into YB- 12s. They had Pratt & Whitney R- 1690-11 'Hornet' radial engines with 775 hp (578 kW) and reached a maximum of 351 km / h.
Another 25 machines of the XB-10 were converted into 25 B-12A . They had larger 1,381 liter fuel tanks and a range of 1995 km.
XB-13
The XB-13 was a version of the B-10 with Pratt & Whitney R-1860-17 radial engines. Ten machines were ordered, but the order was later canceled.
XB-14
The last machine of the 48 XB-10 series received Pratt & Whitney YR-1830-9 twin-Wasp radial engines.
A-15
The A-15 was planned as an attack bomber, but this variant was canceled in favor of the Curtiss A-14 Shrike .
Technical specifications
| Parameter | B-10A data |
|---|---|
| crew | a pilot, two gunmen |
| length | 13.6 m |
| span | 21.5 m |
| height | 4.7 m |
| Wing area | 63 m² |
| Empty mass | 4391 kg |
| Takeoff mass | 7440 kg |
| drive | two radial engines Wright R-1820-33 with 775 HP (578 kW) each |
| Top speed | 346 km / h |
| Service ceiling | 7380 m |
| Range | 2200 km |
| Armament | three 7,62 mm Browning machine guns, 1030 kg bombs |
