

North American’s first bomber design (indeed, it’s first multi-engine aircraft) was the NA-21, built as the XB-21 to compete against the improved B-18A Bolo. First flown in December 1936, the XB-21, with its two Twin Wasp engines, was an advanced design with powered nose and tail turrets. These proved troublesome and were removed, but once reengined with R-2180 Twin Hornets, the XB-21 showed good performance, with a top speed of 220 mph, a range of just under 2,000 miles, and a 10,000lb warload. However, the North American design was almost twice as expensive as the Bolo, and plans for the purchase of a handful of YB-21 service test aircraft were cancelled.
The company’s next try at a bomber design, the NA-40, had the same basic Twin Wasps as the original NA-21, but was otherwise quite different, with a high-mounted wing, slender fuselage with tandem seating, tricycle gear, and twin vertical tails. The NA-40 first flew in January 1939, but performance with the Twin Wasps was disappointing, and the prototype was quickly rebuilt as the NA-40B with R-2600 Twin Cyclones, flying with the new powerplants on 1 March 1939. Performance was improved, but there was little chance to show off the NA-40B before it was lost in an April 1940 crash.
North American was, on the surface, having little success with bombers, but the XB-21 and NA-40 experiences were to prove valuable, as the USAAC had issued a requirement for a new medium bomber even before the NA-40B’s loss. This called for an aircraft that could reach 300 mph, carry a ton and a half of bombs, and had a range of 2,000 miles. North American’s NA-62 contender for this requirement was clearly an NA-40B outgrowth, with a widened fuselage and lowered wing. This won a contract in September 1939 for 184 aircraft, and in September of the following year the prototype B-25 flew.
B-25J walk around

B-25 Bibliography
- Photo: B-25s lined up at Inglewood Flight May 14, 1942 p.474
- Rohm & HAas Company ad, with a photo of a glass-nose Mitchell Aviation July 1942 p.15
- B.F. Goodrich ad, with color artwork depicting a group of B-25s striking a target Aviation November 1942 p.139
- “Exploring the Aerial Arctic” Ad for Curtiss Electric Propellers, with color artwork depicting a B-25 with an icing test rig Aviation November 1943 p.155
- Photo: close-up of a B-25 dorsal turret Aviation December 1943 p.431
- Curtis Fuller “Three-Eyed Mapping” includes a closeup of a recon B-25’s nose, and a shot of the internal tri-metrogon camera equipment Flying January 1944 p.63
- Alfred Friendly “Plane Cannibals” refit of a severely damaged B-25 Flying May 1944
- Photo (small): B-25J 430646 with radar pod under nose and antennas beneath waist positions Aviation News July 22, 1946 p.7
- “B-25 Tip Tanks Give Double Value” Aviation Week July 27, 1953 p.60
- “The Catch-22 Air Force” Extensive photo coverage of the Mitchells used in the filming of Catch-22. Air Classics December 1972. Includes color photos of “Berlin Express”, “Laden Maiden”, “Dumbo” and “Free Fast Ready” nose art.
- Photo: Lineup of RAF Mitchells, one having invasion stripes. RAF Yearbook 1984 p.58-59
- Photo: Tallmantz N1042B with camera extended from bomb bay Aeroplane Monthly March 1987 p.127
- Photo: B-25J in a dissambled state. Warbird International January/February 1989 p.40
- d’Anis Elbied “B-25J Mitchell” Replic March 1994 Finishing the Italeri 1/72 Mitchell as a French aircraft. Includes cockpit photos and diagrams.
- Photo: “Mitchell Rebuild” FlyPast March 1998 p.15 B-25J 43-35972
- “B-25 emerges from the Undergrowth” Aeroplane September 2006 p.6 VB-25N N9089Z
- Preview of the B-25B cockpit detail set for the 1/48 Italeri/Accurate Miniatures Mitchell kit. Skymodel 14/07 p.27
- Photo: large color side view of B-25J 45-8882/N32T in red/black scheme Warbirds International Jan/Feb 2009 p.62-63
- John Fox “B-25” AIR Modeller 33 building the 1/48 Italeri Mitchell
- Preview: B-25J “Glass Nose” in 1/32 from HK Models Model Airplane International July 2012
- Photo: color side-view of B-25 N9117Z in fire tanker markings Warbirds International April/May 2013 p.65
- Rick Turner “Globetrotting with Eight-Seven Zulu” Warbirds International December 2013 numerous photos showing the post-military career of TB-25K 44-86873
- John Lumley “Daisey Mae Mitchell Mk. 2” Model Aircraft April 2016 Kitbashing the Accurate Miniatures B-25C/D as a high-visibility postwar Canadian Mitchell.
Bill Gunston Encyclopedia of World Airpower Aerospace Publishing, 1980 p.283: color profile of a Uruguayan B-25J
Bill Gunston Aircraft of World War II Includes a scale 5-view illustration of a B-25J-1, and color profiles of the NA-40, a B-25 of the 17th BG, a Doolittle Raider B-25B, a PBJ-1D, an RAF Mitchell II, F-10 reconnaissance model, a Chinese B-25H, and a Soviet B-25J.
Bill Gunston Illustrated Encyclopedia of Combat Aircraft of World War II p.247 color in-flight photo of camouflaged B-25J 431162 in Soviet markings
David Mondey The Hamlyn Concise Guide to American Aircraft of World War II p.191-195: Color profiles of a B-25A of the 34th BS, B-25Cs from the 81st, 487th, and 488th Bomb Squadrons, Mitchell Mk. IIs of No 226 and 320 Squadrons, B-25Js of the 498th and 499th Bomb Squadrons, Netherlands, and the RAAF.
Dana Bell Air Force Colors Vol.1 1926-1942 p.77: color profile of a 17th BG B-25B
David Gero Military Aviation Disasters – Significant Losses Since 1908 Haynes Publishing p.34-35: An account of the 1945 crash of a B-25 into the Empire State Building, and a photo of the aftermath.
Yefim Gordon, Sergey Komissarov, Dmitry Komissarov German Aircraft in the Soviet Union and Russia p.282: Photo of a Soviet Lend-Lease B-25J used during the DFS 346 program
Jerry Scutts PBJ Mitchell Units of the Pacific War Includes PBJ-1J and -1H 1/72 scale side view drawings
Steve Pace B-25 Mitchell Units of the MTO includes 1/72 scale side view drawings of the B-25C, B-25D, B-25G, B-25H, and B-25J
Chris Bishop The Encyclopedia of 20th Century Air Warfare p.233: color 3-view of B-25J Betty’s Dream
Aircraft Anatomy of World War II: Technical Drawings of Key Aircraft 1939-1945 Paul Eden, Soph Moeing, editors p.82-85: B-25H cutaway, artwork showing B-25D Dirty Gertie from Bizerte