North American B-25
Crewmen from the 17th Bomb Group, however, were given a unique mission; flying the only Army bombers ever to attack from an aircraft carrier. Led by LtCol. James H. Doolittle, 16 B-25Bs were launched from the USS Hornet on April 18, 1941, each loaded with 2,000 pounds of bombs and 1,141 gallons of fuel, and made a low-level attack on Tokyo and other targets in Japan.
The first mass-production Mitchell was the B-25C (NA-82) with 863 ordered from the Inglewood factory September 28, 1940, and 162 for the Netherlands East Indies on June 24, 1941. A new bomber factory was also begun in Kansas City in December 1940, and an initial order for 1,200 B-25D Mitchells was approved June 28, 1941. This model (NA-87) was to be identical to the B-25C, and the first 100 were assembled from parts made in Inglewood until the Fisher Body Division of General Motors took over parts supply.
The first B-25C, flown on November 9, 1941, was identical to the B-25B except for the R-2600-13 engines with new Holley carburetors, an anti-icing system, and new 24-volt electrical system. Changes introduced on later production aircraft were increased fuel capacity and a navigator’s scanning blister atop the fuselage on plane #385, and these were included on parallel B-25D aircraft.
Most of the first 100 B-25Cs finished by March 1942 were rushed out of the country to help Dutch and Soviet pilots. The first to see combat were 42 B-25Cs flown across the Pacific to Australia. Although intended for the Netherlands East Indies, they were taken over by the 3rd Bomb Group’s 13th and 90th squadrons, which had arrived in Australia without their own aircraft.
On April 6, 1942, the 13th Squadron attacked a Japanese air base on New Guinea with 12 Mitchells, and the 90th flew ten to the Philippines on April 11, where they raided Japanese shipping and returned without loss. These two squadrons were joined in September by a Dutch squadron (No. 18) that had obtained another 18 B-25Cs, and the 38th Bomb Group added two more B-25C squadrons to the Fifth Air Force defending Australia.
China had been told to prepare for a B-25 squadron’s arrival in April, but Doolittle’s force was unable to locate the landing fields at night. In June 1942, two 7th Bombardment Group squadrons got B-25Cs, with the 11th Squadron flying into China, and the 22nd remaining in India to become the nucleus of the 341st Group activated in September by the Tenth Air Force.
The next Mitchell unit in combat was the 12th Bomb Group, which flew 57 B-25Cs across the South Atlantic and Africa to Egypt without a loss. They made their first raid in support of British forces on August 14, 1942.
After the Americans landed in North Africa, three more B-25 groups (310th, 321st, and 340th) had by April 1943 joined the struggle for the Mediterranean under the direction of the Twelfth Air Force. The AAF, however, never used the Mitchell on raids from United Kingdom bases, reserving that role for the B-26.
After 605 B-25Cs were completed at Inglewood by July 1942, and 200 B-25Ds accepted at Kansas City from February to October, production continued with 258 B-25C-l and 100 B-25D-l bombers. They added external wing bomb racks that could hold eight 250-pound bombs in addition to the bomb bay’s racks for two 1,600, three 1,000, or six 500-pound bombs, up to a maximum of 5,200 pounds. A 2,000-pound torpedo could be carried externally, although that was not used in combat by the Army.
Beginning in October 1942, a .50-caliber flexible gun and a .50-caliber fixed gun were mounted in the nose of 162 B-25C-5 (NA-90) and 225 B-25D-5 bombers and most subsequent aircraft, for a total of six .50-caliber guns with 1,350 rounds. Winterization changes were made by December on 150 B-25C-10s and 180 B-25D-10s, while in January 1943, the B-25C-15, and later the B-25D-15, had multiple flame dampening exhaust stacks.
That corrected the bright flame spurts from the older exhaust pipes that could betray the bomber on night raids. Only minor changes were made on the C-20/-25 and parallel D-20/-25 models. Modification centers were set up at Kansas City to prepare newly-delivered aircraft with the different paint and climate gear desired by each user.
Production of the B-25C series was completed in May 1943 with 1,619 built. Deliveries of 1,540 B-25Ds to block D-25 accelerated at Kansas City until they surpassed the output of the California factory. From September 1943 to March 1944, the last blocks of 500 B-25D-30s and 250 B-25D-35s were completed with a single .50-caliber gun in a tail position and the belly turret replaced by a pair of waist guns like those of the B-25H/J models.
A B-25C-10 modified to test a heated surface anti-icing system was designated XB-25E and first flown February 4, 1943, but an XB-25F planned for an alternate system was not completed. Forty-five B-25Ds stripped of armament and fitted with trimetrogon cameras for photo mapping were redesignated as the F-10 on August 18, 1943.
The Fifth Air Force in the Southwest Pacific added its third medium bomber group when the 345th left California with 62 B-25D-5s in May 1943, and began operations in June. The 38th Bomb Group increased from two to four B-25 squadrons by October 1943, and the 22nd Group completely converted to B-25s after the departure of the Martin B-26 Marauder from the Pacific war scene in February 1944. Since the B-26 needed larger airfields and had less range, the B-25’s rival was considered more suitable for Europe.
More pressure on Japan was added with the arrival of the 42nd Group in the South Pacific’s Thirteenth Air Force by April 1943 and the 41st Group in the Central Pacific’s Seventh Air Force in October.