North American B-25 Mitchell was an American twin engined medium bomber manufactured by North American Aviation. Production: 9984.
Variants and serials
Twin-engined five-seat bomber to meet 1938 USAAC requirement for attack bomber. NA-40 was direct B-25 predecessor. Originally powered by two 1,100 hp (820 kW) Pratt & Whitney R-1830-56C3G radials. First flew on 29 January 1939 but proved to be underpowered and difficult to handle, aggravated by engine problems and tail buffet.
The NA-40B (also known as the NA-40-2) was a modification of the NA-40 prototype with two 1,600 hp (1,193 kW) Wright R-2600-A71-3 radials and and a few minor aerodynamic adjustments. First flew in revised form on 1 March 1939. Bomber was crash landed whilst being flown on a single engine.
B-25 (serials 40-2165 – 40-2188)
The design of the NA-62 was approverd in September, 1939 and the first B-25 flow on August 19, 1940. Initial production version of was powered by 1,350 hp (1,007 kW) R-2600-9 2000-9 14-cylinder radial engines each driving a Hamilton-Standard propeler, 12 ft. 7 in. (3.84 m) diameter. The first nine aircraft were built with constant dihedral angle but from the 10th aircraft off the production line the outer wings were re-rigged flat to give the characteristic “gull-wing” arrangement. The first 24 B-25s built were delivered to the USAAC in February 1941. 17th Bomb Group at McChord Field, Washington, was the first unit to go operational with Mitchells.
B-25A (serials 40-2189 – 40-2228)
Similar to the B-25 except that self-sealing fuel tanks in the forward section of the wings and armour (⅜ in /9,5 mm) for the crew were added. Engines were the same Wright R-2600-9 as fitted in the B-25. First version of the Mitchell modified to make it combat ready. The first of 40 B-25As made its maiden flight on February 25, 1941.
B-25B, Mitchell Mk I (serials 40-229 – 40-2348)
This model had a completely revised armament. The nose gun remained but the midship and tail guns were replaced by two Bendix electrically-operated turrets each with two .50 cal. (12.7 mm) machine-guns (Bendix A4 upper turret and an A5 lower turret). The lower turret was retractable and remotely controlled. Lower turret was often removed already in service. The former tail gun position became a prone observation post. B-25B took part in one of the most famous bombing raids of the Second World War. The operation, which was officially known as the Tokyo Raid, was more popularly referred to as the “Doolittle Raid” after its
leader, Lt Col Doolittle.
B-25C, Mitchell Mk II, (NA-82)
B-25C was little changed from the B-25B: autopilot, new powerplants R-2600-13s, de-icing and anti-icing equipment added, the navigator’s astrodome was added; nose armament was increased to two .50 in/ 12.7 mm machine guns, one fixed and one flexible. Range was
raised through the addition of a 152-gallon self-sealing fuel tank in each wing. Later production aircraft were revised further with a modified exhaust system, a cabin heater, provision for a fuel tank in the bomb bay and underwing bomb and torpedo racks. The B-25C model was the first mass-produced Mitchell version. B-25C was built in the Inglewood, California plant.
C: 41-12434 – 41-13038
C-1: 41-13039 – 41-13296
C-5: 42-53332 – 42-53493
C-10: 42-32233 – 42-32382
C-15: 42-32383, 42-32389-42-32532
C-20: 42-64502 – 42-64701
C-25: 42-64702 – 42-64801
B-25D, Mitchell Mk II, (NA-87)
Identical to the B-25C, built in the Kansas City plant.
D: 41-29648 – 41-29847
D-1: 41-29848 – 41-29947
D-5: 41-29947 – 41-30172
D-10: 41-30173 – 41-30352
D-15: 41-30353 – 41-30532
D-20: 41-30533 – 41-30847, 42-87113 – 42-87137
D-25: 42-87138 – 42- 87452
D-30: 42-87453 – 42-8761, 43-3280 – 43-3619
D-35: 43- 620 – 43-3869
B-25C (42-32281) “Flamin’ Maimie” fitted experimentally with heated surface anti-icing equipment to wings and tail surfaces
Another prototype with new electric anti-icing equipment (ex B-25C)
Modified B-25C in which the transparent nose was replaced to create a short nosed gunship carrying two fixed .50 in (12.7 mm) machine guns and a manually loaded 75 mm M4 cannon (21 rounds), then the largest weapon ever carried on an USAAF bomber (9 ft. 0 in. /2.9 m long and weighs ~900 lb/410 kg). Prototype first flown on October 22, 1942
The production model featured increased armor and a greater fuel supply than the XB-25G. The crew is reduced to 5, comprising the pilot (who fires the nose armament and releases the bombs or torpedo), 2nd pilot, navigator, gunner (who mans the upper turret) and radio operator. B-25Gs were likewise field modified to include 2 more .50-caliber/ 12.7 mm guns in the nose plus 4 in blister packs on the fuselage.
G-1: 42-32384 – 42-32388
G-5: 42-64802 – 42-65101
G-10: 42-65102 – 42-65201
45 brand new B-25D modified for photographic reconnaissance. All armament, armour and bombing equipment was removed. Three cameras was installed in the forward section of the bombardier’s nose compartment. This tri-metrogen arrangement consisted of 3x K-17 or T-5 6in/15cm cameras arranged to view directly down and at oblique angles via ‘bug-eye’ apertures on the left and right sides.
An improved version of the B-25G. The forward firing-guns are increased to include 4 50 cal. machine-guns (400 rounds each) in the armoured nose and 2 pairs of .50 cal./12,7 mm pods, one pair on each side of the fuselage in line with the pilot’s cockpit (400 rounds each).
The T13E1 light weight cannon replaced the heavy M4 cannon 75 mm. The top turret is moved forward into the roof of the navigator’s compartment. Between the wings and tail are 2 new waist positions, each armed with one .50 cal/12.7 mm gun. The tail gun mount of the B- 25H and J models used a Bell M-7 mount for a pair of .50-caliber/12.7 mm M-2 machine guns.
H-1: 43-4105 – 43-4404
H-5: 43-4405 – 43-4704
H-10: 43-4705 – 43-5104
NA-98X “Super Strafer”, serial 43-4406
B-25H Fitted with Pratt & Whitney R-2800- 51 engines, first flew on 31 March 1944. Top speed 340mph/547km/h. Plane had square type wing-tips with balanced, 12in/30cm longer ailerons and propeller spinners. Crash on 24 April 1944 by pilot error.
B-25J, Mitchell Mk III
A glazed nose of the B-25C type replaces the armoured nose and the nose armament is reduced to one fixed and one flexible .50 cal./12.7 mm machine-guns. Aft of the nose the armament remains the same as for the B-25H The crew is increased to six to include a bombardier. Some with solid eight-gun nose. The B-25J was the most produced variant of the Mitchell, topping out at 4318 bombers delivered by North American Aviation.
J-1: 43-3870 – 43-4104, 43-27473 – 43-27792
J-5: 43-27793 – 43-28112
J-10: 43-28113 – 43-28222, 43-35946 – 43-36245
J-15: 44-28711 – 44-29110
J-20: 44-29111 – 44-29910
J-25: 44- 29911 – 44-30910
J-30: 44- 30911 – 44-31510, 44-86692 – 44-86891
J-35: 44-86892 – 44-86897, 45-8801 – 45-9242 (45-8900 – 45-9242 not allocated, production terminated)
Mitchells converted for use as staff and VIP transports
Obsolete B-25’s, aircraft no longer considered suitable for its original mission.
AT-24A/TB-25D – 60 trainer modification of B-25D
AT-24B/TB-25G – trainer modification of B-25G.
AT-24C/TB-25C – trainer modification of B-25C.
AT-24D/TB-25J – trainer modification of B-25J.
TB-25K – 117 ex B-25J, Hughes E1 fire-control radar trainer
TB-25L – 90 ex B-25J, Hayes pilot-trainer conversion from 1952
TB-25M – 40 ex TB-25L, trainers for the E-1 and E-5 radar fire control systems
TB-25N – 47 ex B-25J, Hayes navigator-trainer conversion.
Similar to the B-25C for the U.S. Navy. Often fitted with airborne search radar AN/APS-2 or -3 and radio navigation system LORAN. Mostly used in the anti-submarine role. 50 delivered.
(BuNo 35048-35096; 35098-35193; 35196-35202)
Similar to the B-25D for the Navy and USMC, 152 delivered. Often fitted with airborne search radar and used in the anti-submarine role.
(BuNo 35097 ex 42-65031)
U.S. Navy and USMC designation for the B-25G. Trials only.
(BuNo 35250-35297; 88872-89071)
U.S. Navy and USMC designation for the B-25H, 248 delivered.
One specially strengthened and hooked PBJ-1H was used for catapult launch and arrested landing trials on the USS Shangri-la, but the Navy did not continue development.
(BuNo 35194-35195; 35203-35249; 35798-35920; 38980-39012; 64943-64992)
Navy designation for the B-25J-1 to J-35 with improvements in radio and other equipment. Beside the standard armament package, the USMC often fitted with 5 inch underwing rockets and search radar for the anti-shipping/anti-submarine role. The large Tiny Tim rocket-powered warhead saw use in 1945. 255 delivered.
Mitchell Mk I: FK161 – FK183
Mitchell Mk II: FL164 – FL218, FL671 – FL709, FL851 – FL874, FR141 – FR207, FR 208 – FR209, FR362 – FR384, FR 393 – FR397, FV900-FV939, FV940-FV999, FW100-FW280, HD302-HD345, KL133-KL161, MA956-MA957
Mitchell Mk III: HD346-HD400, KJ561-KJ800, KP308-KP328
A47-1 – A47-50
Bibliography and sources
- Jerry Scutts: Marine Mitchells in World War Two
- Jerry Scutts: PBJ Mitchell Units of the Pacific War, Osprey Combat Aircraft 40
- Ernest R. McDowell: B-25 Mitchell in action – Squadron/Signal Publications 1034 Aircraft No. 34
- Rene J. Francillon – USAAF Medium Bomber Units ETO & MTO 1942-45, Osprey Aircam / Airwar 7
- Charles Mendenhall: Deadly Duo: The B-25 and B-26 in WW-II
- Lou Drendel, Don Greer: Walk Around 12 B-25 Mitchell, Squadron Signal 5512
- North American B-25 Mitchell, Famous Airplanes Of The World old series 58 (japanese)
- Roger A. Freeman: North American B-25 Mitchell U.S.A.A.F. 1941-1945, Camouflage and Markings No. 22
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- Pilot Training Manual for the B-25 Mitchell Bomber by US Army Air Force
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- Frederick A. Johnsen: North American B-25 Mitchell – Warbird Tech Volume 12, Specialty Press
- Temporary Handbook of Erection and Maintenance Instructions for the B-25 H-1-NA Medium Bombardment Airplanes, North American Aviation Inc
- William Wolf: North American B-25 Mitchell The Ultimate Look – From Drawing Board to Flying Arsenal, Schiffer Military History Book
- Norm Avery, John W. Lambert: B-25 Mitchell The Magnificent Medium
- Alan C. Carey: Leatherneck Bombers: Marine Corps B-25/PBJ Mitchell Squadrons in World War II, Schiffer Military History Book
- Steve Pace: B-25 Mitchell, Warbird History Series
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- Marek Katarzynski: B-25J “Mitchell” in Combat Over Europe (MTO), Kagero SMI Library 06
- Phil H. Listemann: The North American B-25 in RAAF Service, Allied Wings No. 9
- Ernest R. McDowell: North American B.25A/J Mitchell in U.S.A.A.F. – U.S.M.C. – R.A.F. – Free French – N.E.I.F.F. – K.O.N. Marine & Foreign Service, Osprey Aircam Aviation
- Edwin Schnepf: The Killer Mitchells: The Dramatic True Story of the Allies’ Most Deadly World War Two Medium Bomber – Air Classics Special 3
- Dana Bell: Air Force Colors Volume 3, Pacific and Home Front 1942-47, Squadron/Signal Publications 6152
- Andre Zbigniewski: 345 BG Vol 1, Kagero Air Miniatures 32
- Ray Wagner: The North American B-25A to G Mitchell, Aircraft Profile Number 59
- North American: Company Profile 1928-1996, Aeroplane Company Profile