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American Combat Planes of the 20th Century is an incredible reference for anyone who is interested in any American Combat Plane History. There are 758 pages and 1700 b/w photos in this substantial labor of love by Ray Wagner, who has been passionately researching and writing about aircraft for over 50 years. Whether you are already familiar with his past works, or just discovering this accomplished author for the first time... This is the book that you've been waiting for!

If you'd like to see the book's Table of Contents ... Click here. You can also browse the entire Index Section to get an idea of the extensive amount of information that is covered within this book.

Search our site for other combat planes. A- 1 Eaton A- 4 Skyhawk A- 6 & A- 7 Air Weapons AV- 8 to A- 10 A- 20 Havoc A- 22 Martin Maryland A- 23 Martin Baltimore A- 24 Douglas A- 26 Douglas Invader Attack Planes B- 2A, F-111, F-117 Stealth B- 17 Flying Fortress B- 24 Liberator B- 25 North American B- 26 Marauder B- 29 Superfortress B- 32 Dominator B- 35 Flying Wing B- 36 B- 47 Stratojet B- 50 Boeing B- 52 Stratofortress B- 57 Canberra B- 58 Hustler Biplanes Biplanes, Army Pursuits Bombers, B- 70 to Stealth Bombers, First Big Curtiss Falcon CO- 1 DH- 4 De Havilland F3D- Douglas Skyknight F3H- McDonnell Demon F4D- 1 Skyray F4F Grumman Wildcats F- 4U Corsair F6F Grumman F7F Grumman F7U Vought F9F G. Cougar F9F G. Panther F- 16 Fighting Falcon F- 84 F- 86 Sabre F- 89 to F-94 F- 100 to F-108 First Fighters Flying Boats GAX Iraq to Afghanistan Martin Bombers Missile Era Fighters Navy Fighers Navy Flying Boats O- 2 Douglas P- 35 Seversky P- 36 to 42 Curtiss P- 38 Lightning P- 39 Airacobra P- 40 Line P- 47 Thunderbolt P- 51 Mustang Fighter P- 61 Black Widow P- 63 Kingcobra P- 79 to P-81 P- 82 Twin Mustang SB2C Helldiver TBF-TBM Avenger Thomas-Morse Torpedo Planes V- 11 Vultee XB -28 XP -48 / 77

CRISIS-BORN FIGHTER PROJECTS, XP-48 TO XP-77

XP-69, XP-72, XP-75

Page 9

Republic XP-72
When Republic began work in September 1941 on the XP-69 with a Wright R-2160, it also studied a Model AP-19 designed at the same time around the Pratt & Whitney Wasp Major radial engine. No urgency was attached to the project until the Air Force realized that the Wright power plant was not going to be ready on time and that the air-cooled Wasp Major had better prospects. After the XP-69 was canceled, two XP-72 interceptor prototypes were ordered June 18, 1943. GENERAL MOTORS XP-75-GM

Powered by an 3,450-hp R-4360-13 with a four-bladed propeller and a gear-driven supercharger, the XP-72 was similar in appearance to the P-47 except for the enlarged landing gear and air scoop under the fuselage. Six 50-caliber wing guns with 267 rpg and 3/8-inch cockpit armor was provided, as well as wing racks for two 1,000-pound bombs or 150-gallon drop tanks to increase the radius of action to 735 miles.

The first XP-72 flew on February 2, 1944, while the second one was flown June 26 with an R-4360-19 and six-bladed contra props. A plan to build 100 production P-72s was dropped when it was learned that jet propulsion would provide even faster fighters.

General Motors P-75
General Motors, the largest American auto manufacturer, had established a New Jersey branch to build Grumman aircraft, but the name recognition of producing its own design was attractive. In January 1942 Don R. Berlin, who designed the P-40, was hired to plan a fighter using the V-3420-19 of that company’s Allison engine division.

A proposal presented at Wright Field on September 10 resulted in a letter contract dated October 10, 1942, for two XP-75 prototypes to be built in Detroit. How the P-75 designation was chosen isn’t clear, for no P-73 or P-74 was assigned, although P-73 had been suggested for the Hughes D-2 in June 1942. Perhaps symbolism was a motive; the French 75-mm cannon in World War I, P-75 in World War II. GENERAL MOTORS P-75A-GC

The largest liquid-cooled engine available mounted behind the pilot, Airacobra-style, drove two co-axial, three-bladed props in the nose with twin power shafts. To speed development, parts from aircraft already in production were used, including Curtiss P-40 outer wings, the Douglas A-24 tail section, and the Vought F4U landing gear. Armament included four .50-caliber synchronized nose guns with 300 rpg, six .50-caliber wing guns with 235 rpg, two 1,000-pound bombs, and 177-pounds of cockpit armor. The October 13, 1942, specification promised a top speed of 426 mph at 20,000 feet. GENERAL MOTORS XP-75-GC

Even before the XP-75-GM began flight tests, General Oliver P. Echols, Chief of Materiel Command, met with Don Berlin on July 6, 1943, to decide how the P-75 might meet the pressing need for an escort fighter to protect long-range bombers. It was decided to order six XP-75-GC preproduction prototypes with increased fuel capacity and production V-3420-23 engines. A letter of intent was written July 8, 1943, to produce 2,500 P-75A-GCs at the General Motors Fisher Body plant in Cleveland, originally built to make B-29 parts. The Air Force was told it would get the first P-75A-1 in May 1944, and have 586 by the end of October, with 250 delivered each month.

Flight tests started November 17, 1943, showed the XP-75 suffering from instability, low rate of roll, poor spinning characteristics, and trouble with the engine, (actually two V-1710s joined side by side). Redesign of the six Cleveland prototypes replaced the A-24 tail and improved things somewhat, but spoiled the quick-production advantage of the original components. Tests began at Cleveland in February, and the fifth XP-75 crashed on April 8.

The first production P-75A-1 “Fisher Eagle” was not flown until September 15, 1944, proved 30 mph below the guaranteed speed, and had a fatal crash on October 10. The P-75A program was terminated October 27, reducing production to only six aircraft. Fortunately the P-51 had solved the long-range fighter problem, but the XP-75 contract had cost $9,373,629, and the P-75 production fiasco millions more.

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