B-25 Mitchell, North American


B-25 Mitchell

The most built and used medium bomber of the war, a shoulder-wing monoplane. The B-25 was easily recognizable: The inboard sections of the wing had dihedral, but the outboard sections not, and the B-25 had twin fins. Some versions had a glazed nose for the bombardier, while others had a metal nose filled with machine guns or even a 75mm cannon. The 'Doolittle raid' on Tokyo made the B-25 famous. B-25s lend-leased to the USSR continued their service there after WWII, and had the NATO reporting name 'Bank'. 9816 built.

Type: B-25J
Country: USA
Function: bomber
Year: 1943
Crew: 6 (two pilots, navigator/bombardier, turret gunner/engineer, radio operator/waist gunner, tail gunner)
Engines: 2 * 1250 kW Wright R-2600-29 "Cyclone" radials
Wing Span: 20.60 m
Length: 16.13 m
Height: 4.98 m
Wing Area: 56.67 m2
Wing loading: 270 kg/m²
Empty Weight: 8836 kg (some other sources report 9580 kg)
Max.Weight: 15876 kg
Speed: 438 km/h
Cruise speed: 370 km/h
Ceiling: 7375 m
Rate of climb: 4 m/s
Combat Range: 2170 km
Ferry Range: 4300 km
Armament: 12 or 13*mg 12.7 mm, 2700kg


History:

The B-25 was made immortal on April 18, 1942, when it became the first United States aircraft to bomb the Japanese mainland. Commanded by Lieutenant Colonel James Doolittle, sixteen Mitchells took off from the aircraft carrier USS Hornet, flew 800 miles (1287 km) to Japan, and attacked their targets. Most made forced landings in China. They were the heaviest aircraft at the time to be flown from a ship at sea.

The B-25 was designed for the United States' Army Air Corps before the Second World War. The North American company had never designed a multi-engine bomber before. The original design had shoulder-mounted wings and a crew of three in a narrow fuselage. The USAAC then decided its new bomber would need a much larger payload -- double the original specifications. North American designers dropped the wing to the aircraft's mid-section, and widened the fuselage so the pilot and co-pilot could sit side-by-side. They also improved the cockpit. The USAAC ordered 140 aircraft of the new design right off the drawing board. There were at least six major variants of the Mitchell, from the initial B-25A and B-25B, with two power-operated two-gun turrets, to the autopilot-equipped B-25C, and the B-25G with 75mm cannon for use on anti-shipping missions. The British designated the B-25Bs as the Mitchell I, the B-25C and B-25Ds as the Mitchell II, and their B-25Js, with 12 heavy machine guns, as the Mitchell III. The US Navy and Marine Corps designated their hard-nosed B-25Js as the PBJ-1J. In the end, the B-25 became the most widely used American medium bomber of World War Two.

After the war, many B-25s were used as training aircraft. Between 1951 and 1954, 157 Mitchells were converted as flying classrooms for teaching the Hughes E-1 and E-5 fire control radar. They were also used as staff transport, utility, and navigator-trainer aircraft. The last B-25, a VIP transport, was retired from the USAF on May 21, 1960. Approximately 34 B-25 Mitchells remain flying today.

Development:

The B-25 was a descendant of the earlier XB-21 (North American-39) project of the mid-1930s. Experience gained in developing that aircraft was eventually used by North American in designing the B-25 (called the NA-40 by the company). One NA-40 was built, with several modifications later being done to test a number of potential improvements. These improvements included Wright R-2600 radial engines, which would become standard on the later B-25.

In 1939, the modified and improved NA-40B was submitted to the United States Army Air Corps for evaluation. This plane was originally intended to be an attack bomber for export to the United Kingdom and France, both of which had a pressing requirement for such aircraft in the early stages of World War II. However, those countries changed their minds, opting instead for the also-new Douglas A-20 Havoc. Despite this loss of sales, the NA-40B re-entered the spotlight when the Army Air Corps evaluated it for use as a medium bomber. Unfortunately, the NA-40B was destroyed in a crash on April 11, 1939. Nonetheless, the type was ordered into production, along with the Army's other new medium bomber, the Martin B-26 Marauder.
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