The B-25 first gained fame as the bomber used in the April 18, 1942 Doolittle Raid, in which 16 B-25Bs led by Lieutenant Colonel Jimmy Doolittle attacked mainland Japan, four months after the bombing of Pearl Harbor. The mission gave a much-needed lift in spirits to the Americans, and alarmed the Japanese who had believed their home islands were inviolable by enemy forces. Although the amount of actual damage done was relatively minor, it forced the Japanese to divert troops for the home defense for the remainder of the war. The raiders took off from the carrier USS Hornet and successfully bombed Tokyo and four other Japanese cities without loss. However, 15 B-25 bombers subsequently crash-landed en route to recovery fields in Eastern China. These losses were the result of the task force being spotted by a Japanese vessel forcing the bombers to take off 170 mi (270 km) early, fuel exhaustion, stormy nighttime conditions with zero visibility, and lack of electronic homing aids at the recovery bases. Only one B-25 bomber landed intact; it came down in the Soviet Union, where its five-man crew was interned and the aircraft confiscated. Of the 80 aircrew, 69 survived their historic mission and eventually made it back to American lines.

North American B-25 Mitchell
[Source: Unknown]

Following a number of additional modifications, including the addition of Plexiglas windows for the navigator and radio operator, heavier nose armament, and deicing and anti-icing equipment, the B-25C was released to the Army. This was the second mass-produced version of the Mitchell, the first being the lightly armed B-25B used by the Doolittle Raiders. The B-25C and B-25D differed only in location of manufacture: -Cs at Inglewood, California, -Ds at Kansas City, Kansas. A total of 3,915 B-25Cs and -Ds were built by North American during World War II.

North American B-25 Mitchell
[Source: Unknown]

Although the B-25 was originally designed to bomb from medium altitudes in level flight, it was used frequently in the Southwest Pacific theater (SWPA) on treETOp-level strafing and parafrag (parachute-retarded fragmentation bombs) missions against Japanese airfields in New Guinea and the Philippines. These heavily armed Mitchells, field-modified at Townsville, Australia, by Major Paul I. "Pappy" Gunn and North American tech rep Jack Fox, were also used on strafing and skip-bombing missions against Japanese shipping trying to resupply their land-based armies. Under the leadership of Lieutenant General George C. Kenney, B-25s of the Fifth and Thirteenth Air Forces devastated Japanese targets in the Southwest Pacific theater from 1942 to 1945, and played a significant role in pushing the Japanese back to their home islands. B-25s were also used with devastating effect in the Central Pacific, Alaska, North Africa, Mediterranean and China-Burma-India (CBI) theaters.

Because of the urgent need for hard-hitting strafer aircraft, a version dubbed the B-25G was developed, in which the standard-length transparent nose and the bombardier were replaced by a shorter solid nose containing two fixed .50 in (12.7 mm) machine guns and a 75 mm (2.95 in) M4 cannon, one of the largest weapons fitted to an aircraft, similar to the experimental British Mosquito Mk. XVIII, and German Ju 88P heavy cannon carrying aircraft. The cannon was manually loaded and serviced by the navigator, who was able to perform these operations without leaving his crew station just behind the pilot. This was possible due to the shorter nose of the G-model and the length of the M4, which allowed the breech to extend into the navigator's compartment.

North American B-25 Mitchell
[Source: Unknown]

The B-25G's successor, the B-25H, had even more firepower. The M4 gun was replaced by the lighter T13E1, designed specifically for the aircraft. The 75 mm (2.95 in) gun fired at a muzzle velocity of 2,362 ft/s (about 720 m/s). Due to its low rate of fire (approximately four rounds could be fired in a single strafing run) and relative ineffectiveness against ground targets, as well as substantial recoil, the 75 mm (2.95 in) gun was sometimes removed from both G and H models and replaced with two additional .50 in (12.7 mm) machine guns as a field modification. Besides that, the -H normally mounted four fixed forward-firing .50 (12.7 mm) machine guns in the nose, four more fixed ones in forward-firing cheek blisters, two more in the manned dorsal turret, one each in a pair of new waist positions, and a final pair in a new tail gunner's position. Company promotional material bragged the B-25H could "bring to bear 10 machine guns coming and four going, in addition to the 75 mm cann on, a brace of eight rockets and 3,000 lb (1,360 kg) of bombs."

North American B-25 Mitchell WRG# 0000065
North American B-25H Mitchell
[Source: North American Aviation via Mark Nankivil]

The B-25H also featured a redesigned cockpit area, required by the dorsal turret having been relocated forward to the navigator's compartment - just aft of the cockpit and just ahead of the leading edge wing roots, thus requiring the addition of the waist and tail gun positions - and a heavily modified cockpit designed to be operated by a single pilot, the co-pilot's station and controls deleted, and the seat cut down and used by the navigator/cannoneer, the radio operator being moved to the aft compartment, operating the waist guns. A total of 405 B-25Gs and 1000 B-25Hs were built, the 248 of the latter being used by Navy as PBJ-1H.

North American B-25 Mitchell
[Source: Unknown]

The final, and the most built, version of the Mitchell, the B-25J, looked much like the earlier B, C and D, having reverted to the longer, glazed bombardier's nose, but with the -H version's relocated-forward dorsal manned turret. The less-than-successful 75 mm (2.95 in) cannon was deleted. Instead, 800 of this version were built with a solid nose containing eight .50 (12.7 mm) machine guns, while other J-models featured the earlier "greenhouse" style nose containing the bombardier's position. Regardless of the nose style used, all J-models also included two .50 in (12.7 mm) guns in a "fuselage package" located directly under the pilot's station, and two more such guns in an identical package just under the co-pilot's compartment, with the co-pilot's seat and flight controls restored to their previous locations. The solid-nose B-25J variant carried an impressive total of 18 .50 in (12.7 mm) light-barrel AN/M2 Browning M2 machine guns: eight in the nose, four in under-cockpit confo rmal gun pod packages, two in the dorsal turret, one each in the pair of waist positions, and a pair in the tail - with fourteen of the guns either aimed directly forward, or aimable to fire directly forward for strafing missions. No other main series production bomber of World War II carried as many guns. The first 555 B-25Js (the B-25J-1-NC production block) were delivered without the fuselage package guns, because it was discovered that muzzle blast from these guns was causing severe stress in the fuselage; this problem was cured with heavier fuselage skin patches. Although later production runs returned these fuselage package guns to the aircraft, they were often removed as a field modification for the same reason. Later B-25J was additionally armed with eight 5 in (130 mm) high velocity aircraft rockets (HVAR). In all, 4,318 B-25Js were built.

North American B-25 Mitchell WRG# 0000066
North American B-25J Mitchell/43-4570.
[Source: North American Aviation via Mark Nankivil]

By the time a separate United States Air Force was established in 1947, most B-25s had been consigned to long-term storage. However, a select number continued in service through the late 1940s and 1950s in a variety of training, reconnaissance and support roles. Its principal use during this period was for undergraduate training of multi-engine aircraft pilots slated for reciprocating engine or turboprop cargo, aerial refueling or reconnaissance aircraft. Still others were assigned to units of the Air National Guard in training roles in support of Northrop F-89 Scorpion and Lockheed F-94 Starfire operations. TB-25J-25-NC Mitchell, 44-30854, the last B-25 in the USAF inventory, assigned at March AFB, California as of March 1960, was flown to Eglin AFB, Florida, from Turner Air Force Base, Georgia, on 21 May 1960, the last flight by a USAF B-25, and presented by Brig. Gen. A. J. Russell, Commander of SAC's 822d Air Division at Turner AFB, to the Air Proving Ground Center Commander, B rig. Gen. Robert H. Warren, who in turn presented the bomber to Valparaiso, Florida Mayor Randall Roberts on behalf of the Niceville-Valparaiso Chamber of Commerce. Four of the original Tokyo Raiders were present for the ceremony, Col. Davy Jones, Col. Jack Simms, Lt. Col. Joseph Manske, and retired Master Sgt. Edwin W. Horton. It was donated back to the Air Force Armament Museum c. 1974 and marked as Doolittle's 40-2344.

Today, many B-25s are kept in airworthy condition by air museums and collectors.

U.S. Navy and USMC
The PBJ-1 was a navalized version of the USAAF B-25. It had its origin in a deal cut in mid-1942 between the Navy and the USAAF. As part of the deal, 50 B-25Cs and 152 B-25Ds were transferred to the Navy from the USAAF. The bombers carried Navy serial numbers beginning with 34998. The first PBJ-1s arrived in February 1943. They were used by Marine Corps pilots, beginning with VMB-413. Many of them were equipped with a search radar with a retractable radome fitted in place of the ventral turret.

Large numbers of B-25H and J variants were delivered to the Navy as PBJ-1H and PBJ-1J respectively. These aircraft joined, but did not necessarily replace, the earlier PBJs.

North American B-25 Mitchell WRG# 0000740
PBJ Mitchell of VMB-611 after suffering a nose wheel collapse.
[Source: National Archives via the Jack Cook Collection]

The PBJs were operated almost exclusively by the Marine Corps as land-based bombers. To operate them, the U.S. Marine Corps established a number of bomber squadrons, beginning with VMB-413, in March 1943 at Cherry Point, North Carolina. Eight VMB squadrons were flying PBJs by the end of 1943, forming the initial Marine Medium Bombardment Group. Four more squadrons were in the process of formation in late 1945, but had not yet deployed by the time the war ended.

Operational use of the Marine Corps PBJ-1s began in March 1944. The Marine PBJs operated from the Philippines, Saipan, Iwo Jima and Okinawa during the last few months of the Pacific war. Their primary mission was the long range interdiction of enemy shipping that was trying to run the blockade which was strangling Japan. The weapon of choice during these missions was usually the five-inch HVAR rocket, eight of which could be carried on underwing racks. Many of the PBJ-1C and D versions carried a rather ugly, bulbous antenna for an APS-3 search radar sticking out of the upper part of the transparent nose. On the PBJ-1H and J, the APS-3 search radar antenna was usually housed inside a ventral or wingtip radome. Some PBJ-1Js had their top turrets removed to save weight, especially toward the end of the war when Japanese fighters had become relatively scarce.

After World War Two, some PBJs were stationed at the Navy's rocket laboratory at Inyokern, California to test various air to ground rockets and arrangements; including a twin barrel nose arrangement that could fire ten spin stabilized 5 inch rockets in one salvo.

Royal Air Force
The Royal Air Force (RAF) was an early customer for the B-25 via Lend-Lease. The RAF was the only force to use the B-25 on raids against Europe from bases in the United Kingdom, as the USAAF used the Martin B-26 Marauder for this purpose instead.

The first Mitchells were designated Mitchell I by the RAF and were delivered in August 1941, to No 111 Operational Training Unit based in the Bahamas. These bombers were used exclusively for training and familiarization and never achieved operational status. The B-25Cs and Ds were designated Mitchell II, altogether, 167 B-25Cs and 371 B-25Ds were delivered to the RAF.

North American B-25 Mitchell WRG# 0000071
North American B-25D Mitchell of the Royal Air Force.
[Source: North American Aviation via Mark Nankivil]

A total of 93 Mitchell Is and IIs had been delivered to the RAF by the end of 1942 and served with No. 2 Group RAF, the RAF's tactical medium bomber force. The first RAF operation with the Mitchell II took place on 22 January 1943, when six aircraft from No. 180 Squadron RAF attacked oil installations at Ghent. After the invasion of Europe, all four Mitchell squadrons moved to bases in France and Belgium (Melsbroek) to support Allied ground forces. The British Mitchell squadrons were joined by No. 342 (Lorraine) Squadron of the French Air Force in April 1945.

No 305 (Polish) Squadron flew Mitchell IIs from September to December 1943 before transitioning to Mosquitos. In addition to the 2nd Group, the B-25 was used by various second-line RAF units in the UK and abroad. In the Far East, No. 3 PRU, which consisted of Nos. 681 and 684 Squadrons, flew the Mitchell (primarily Mk IIs) on photographic reconnaissance sorties.

The RAF was allocated 316 B-25Js which entered service as the Mitchell III. Deliveries took place between August 1944 and August 1945. However, only about 240 of these bombers actually reached Britain, with some being diverted to No. 111 OTU in the Bahamas, some crashing during delivery and some being retained in the United States.

Royal Canadian Air Force
The Royal Canadian Air Force (RCAF) was an important user of the B-25 Mitchell, although most of the RCAF use of the Mitchell was postwar. The first B-25s for the RCAF had originally been diverted to Canada from RAF orders. These included one Mitchell I, 42 Mitchell IIs, and 19 Mitchell IIIs. No 13 (P) Squadron was formed unofficially at Rockcliffe in May 1944. They operated Mitchell IIs on high altitude aerial photography sorties. They retained the Mitchell until October 1948.

No 418 (Auxiliary) Squadron received its first Mitchell IIs in January 1947. It was followed by No 406 (auxiliary) which flew Mitchell IIIs from April 1947 to June 1958. No 418 Operated a mix of IIs and IIIs until March 1958. No 12 Squadron of Air Transport Command also flew Mitchell IIIs along with other types from September 1956 to November 1960. In 1951, the RCAF received an additional 75 B-25Js from USAF stocks to make good attrition and to equip various second line units.

Royal Australian Air Force
The Australians got Mitchells by the spring of 1944. The joint Australian-Dutch No. 18 (Netherlands East Indies) Squadron RAAF had more than enough Mitchells for one squadron so the surplus went to re-equip the RAAF's No. 2 Squadron, replacing their Beauforts.

Dutch Air Force
During the World War II, the Mitchell served in fairly large numbers with the Air Force of the Dutch government-in-exile. They participated in combat both in the East Indies as well as on the European front. On 30 June 1941, the Netherlands Purchasing Commission, acting on behalf of the Dutch government in exile in London, signed contract with North American Aviation for 162 B-25C aircraft. The bombers were to be delivered to the Netherlands East Indies to help deter any Japanese aggression into the region.

In February 1942, the British Overseas Airways Corporation (BOAC) agreed to ferry 20 of the Dutch B-25s from Florida to Australia via Africa and India, and an additional 10 via the South Pacific route from California. During March, five of the bombers on the Dutch order had reached Bangalore, India and 12 had reached Archerfield in Australia. It was agreed that the B-25s in Australia would be used as the nucleus of a new squadron, designated No. 18. This squadron would be staffed jointly by Australian and Dutch aircrews plus a smattering of aircrews from other nations, but would operate at least initially under Royal Australian Air Force command. However, the B-25s of No. 18 Squadron would be painted with the Dutch national insignia (at this time a rectangular Netherlands flag) and would carry NEIAF serials. Discounting the 10 "temporary" B-25s delivered to 18 Squadron in early 1942, a total of 150 Mitchells were taken on strength by the NEIAF, 19 in 1942, 16 in 1943, 87 in 1944, and 28 in 1945. They flew bombing raids against Japanese targets in the East Indies. In 1944, the more capable B-25J Mitchell replaced most of the earlier C and D models.

In June 1940, No. 320 Squadron RAF had been formed from personnel formerly serving with the Royal Dutch Naval Air Service who had escaped to England after the German occupation of the Netherlands. Equipped with various British aircraft, No. 320 Squadron flew anti-submarine patrols, convoy escort missions, and performed air-sea rescue duties. They acquired the Mitchell II in September 1943, performing operations over Europe against gun emplacements, railway yards, bridges, troops and other tactical targets. They moved to Belgium in October 1944, and transitioned to the Mitchell III in 1945. No. 320 Squadron was disbanded in August 1945. Following the war, B-25s were used in a vain attempt of the Dutch to retain control of Indonesia.

Soviet Air Force
The U.S. supplied 862 B-25(of B,D,G and J types) aircraft to the Soviet Union under Lend-Lease during the Second World War via the Alaska-Siberia ALSIB ferry route.

A Russian B-25 Mitchel, supplied through Lend-Lease, arriving in Alaska late summer 1942. WRG #: 0021477
A Russian B-25 Mitchel, supplied through Lend-Lease, arriving in Alaska late summer 1942.
[Source: USAF Photo via Mark Allen Collection]

Other damaged aircraft arrived or crashed in the Far East of Russia, and one Doolittle Raid aircraft landed there short of fuel after attacking Japan. It is not known what happened to these latter aircraft. In general, the B-25 was operated as a ground support and tactical daylight bomber (as similar Douglas A-20 Havocs were used). It saw action in fights from Stalingrad (with B/D models) to the German surrender during May 1945 with (G/J types).

China Air Force
Well over 100 B-25Cs and Ds were supplied to the Nationalist Chinese during the Second World War. In addition, a total of 131 B-25Js were supplied to China under Lend-Lease.

The four squadrons of the 1st BG (1st, 2nd, 3rd, and 4th) of the 1st Medium Bomber Group were formed during the War. They formerly operated Russian-built Tupolev SB bombers, then transferred to the B-25. The 1st BG was under the command of CACW (Chinese-American Composite Wing) while operating B-25. Following the end of the war in the Pacific, these four bombardment squadrons were established to fight against the Communist insurgency that was rapidly spreading throughout the country. During the civil war, Chinese Mitchells fought alongside de Havilland Mosquitos.

In December 1948, the Nationalists were forced to move to the island of Taiwan, taking many of their Mitchells with them. However, some B-25s were left behind and were impressed into service with the air force of the new People's Republic of China.

Brazilian Air Force
During the war, the Força Aérea Brasileira (FAB) received a few B-25s under Lend-Lease. Brazil declared war against the Axis powers in August 1942 and participated in the war against the U-boats in the southern Atlantic. The last Brazilian B-25 was finally declared surplus in 1970.

Free French
At least 21 Mitchell IIIs were issued by the Royal Air Force to No 342 Squadron, which was made up primarily of Free French aircrews.

Following the liberation of France, this squadron was transferred to the newly formed French air force (Armée de l'Air) as GB I/20 Lorraine. These aircraft were operated by GB I/20 after the war, some being converted from bomber configuration into fast VIP transports. They were finally struck off charge in June 1947.