B-25J 43-27485 9T named MISSION COMPLETED of 340th BG, 489th BS
The B-25J was the final production variant of the Mitchell bomber and the most widely produced, with a total of 4,318 delivered. Most B-25Js retained the framed glass bombardier’s nose that had been standard on earlier versions, but 72 additional aircraft completed towards the end of the war were not delivered under contract and were later modified for other missions.
To enhance its effectiveness in the strafing role, some B-25Js were outfitted with solid noses featuring eight .50-caliber machine guns arranged in two vertical rows of four. Kits for this solid nose configuration were also available for field conversions. Defensive armament on the B-25J remained consistent with the B-25H, including the forward-mounted top turret in the navigator’s compartment, staggered waist gun positions, and a twin tail turret.
The cockpit of the B-25J reverted to a dual configuration with both pilot and co-pilot seats and controls. Instruments were rearranged to suit two-pilot operations. The flash shield installed on the pilot’s windshield on previous models was retained on most B-25Js, though some aircraft had the metal plate replaced with a clear perspex section framed with metal.
Modifications to the bomb bay allowed for an increase in the number of 1,000-pound bombs carried from two to three, and the capability to load two 1,600-pound armor-piercing bombs for hardened targets was introduced. The B-25J could also carry six 325-pound depth charges on wing racks. Beginning with the B-25J-1-NC, serial number 43-4019, the ability to carry a 2,000-pound bomb was removed.
Contrary to popular belief, the B-25J did not uniformly feature the strapon gun packs on the forward fuselage. The initial 555 B-25J-1-NCs were delivered without these side gun packs, which were added in later production blocks but were often removed in the field due to fuselage stress caused by muzzle blast. Starting with the B-25J-5-NC, serial number 43-27793, the N3B gun sight was replaced with the N3C, though the A-1 bombing head was retained. The N3C was subsequently replaced by the N9B in later production. Deicing panels and blast arresters for the top turret’s guns were introduced, and electrically operated bomb racks and doors were added from the B-25J-10-NC, serial number 43-35995. Optical sights were introduced for the waist guns starting with the B-25J-15-NC, serial number 44-28711.
From B-25J-20-NC, serial number 44-29111, a second fixed .50-caliber machine gun was added to the right side of the bombardier’s nose. This modification was also applied to many existing aircraft at Townsville, Australia, where a second pair of fixed guns was installed on the left side of the nose as well. To manage the considerable gun gas generated, a gun gas extractor was installed in a fairing under the nose.
During the production of the B-25J-20-NC, additional reinforcements were made to the top turret dome, the mount for the flexible nose gun was raised, and armor protection was added for the bombardier. Beginning with the B-25J-25-NC, serial number 44-29911, new armored seats with hinged plates were introduced for the pilot and co-pilot to facilitate cockpit access.
Armament capabilities continued to improve, with provisions for T-64 zero-length launchers under the wings for carrying 5-inch rockets starting with the B-25J-30-NC, serial number 44-31338. The tail turret was equipped with a K-10 lead-computing sight and an M8A gun mount from serial number 44-31491. Glide bombing provisions were added starting with serial number 44-86692, and from B-25J-35-NC, serial number 44-86892, the capability to carry and deploy aerial mines was introduced.
The U.S. Navy’s Bureau of Aeronautics acquired 244 B-25Js, redesignated as PBJ-1Js. This was the largest number of any Mitchell variant procured by the Navy. Many of these aircraft had search radars added to their starboard wing tips or nose. Some aircraft assigned to VMB-612 were modified to carry two Tiny Tim rockets on the fuselage sides next to the bomb bay.
The Royal Air Force acquired 314 B-25Js, designating them as Mitchell III. Other nations that operated the B-25J during the war included Australia, Brazil, China, Canada, and the Netherlands. Post-war, Argentina received three B-25Js for private use, while Chile, Colombia, Mexico, Peru, Uruguay, and Venezuela also operated small numbers of B-25Js.
The Mitchell airframe proved adaptable for various non-combat roles after the war. Several VIP transports were converted from standard airframes, initially designated RB-25s (with “R” standing for restricted). Two of these went to Generals Henry “Hap” Arnold and Dwight D. “Ike” Eisenhower. Post-war, more transports were converted and designated VB-25. The RB-25 designation was reassigned to remaining F-10 reconnaissance aircraft. Both VB-25J and VB-25N VIP transports were converted.
The B-25’s airframe continued to be versatile, with many converted to trainers. Wartime training versions designated AT-24D were re-designated as TB-25J in June 1948. Some of these trainers were used for multi-engine transition or refresher training and were often designated TB-25L. Radar training versions included the TB-25K for the Hughes E-1 radar/fire control system and the TB-25M for the E-5 system. JB-25Js, JTB-25Js, and JTB-25Ns were used for special tests, while other Mitchells served as hack or utility aircraft, towing targets and performing non-combat roles.