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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

The Biplane Period, 1917 to 1932

Page 7

Landing speed, while not tactically significant, is included in the specifications because it is a measure of relative safety, and is one of the earliest limiting points selected in the design of an aircraft. The faster the necessary landing speed, the more difficult the landing. Landing speed depends on wing loading and the lifting efficiency of the wing. Stalling speed, at which the airplane stalls, is the minimum speed of flight, and is often cited in tables instead of landing speed.

A designer begins his task with a proposed specification that gives the armament and performance required. Traditional design procedure began with an estimate of weight, as this is the prime limiting factor of aircraft. A list of the essential parts of the useful load is totaled, including crew, armament, equipment, and probable fuel required. This is added to a rough estimate, from past experience, of the engine and airframe weight required to support such a load. Useful load and empty weight are added to make estimated gross weight.

An appropriate wing section and form is then selected; a high-lift airfoil profile for a bomber, or a low-drag airfoil for the fighter. Aspect ratio (the ratio of the wing span to the mean wing chord) is decided upon; a high aspect ratio for a long-range machine like the B-29, or a short, stubby wing for an interceptor.

American World War I aircraft used the thin airfoil profiles developed in Britain and France by the Royal Aircraft Factory and Eiffel laboratories. But while such thin wings had less drag, they required bracing by outside struts and wires. Germany, however, often favored the thick airfoils developed at the Goettingen wind tunnel. On planes like the Fokker D VII, they provided higher lift without much more drag. Most important was that thicker wings allowed a stronger internal structure, even a cantilever beam supported at one end only, without external struts.

The Clark Y airfoil appeared in 1923, and used on most Curtiss and Douglas warplanes, combined the Goettingen profile with a flat undersurface for easier manufacturing. By 1933, the Variable-Density wind tunnel at Langley Field enabled the NACA (National Advisory Committee for Aeronautics) to develop a family of 78 airfoil profiles of different qualities. World War II aircraft especially used the 230 series.

Once the airfoil and aspect ratio have been chosen, designers must determine what wing loading would permit the desired landing speed and desired flight qualities. Then the necessary wing area is given by dividing the gross weight by the wing loading. Lift-increasing devices such as landing flaps and wing slots can be added to reduce the wing area without raising the landing speed. The introduction of tricycle landing gear on combat planes in 1939 made feasible higher landing speeds, since the nose wheel permits more sudden stops. However, wing loading should not be increased to a point too detrimental to climb and maneuverability.

When the weight has been estimated, the wing chosen, and the general layout planned, the performance of aircraft depends on its power loading. This leads to the next problem: the selection of a power plant.

Power Plants
To a designer the important features of an airplane engine are its power, weight, size, arrangement and number of cylinders, and the method of cooling. The reader should notice what the official designation tells about an engine. Allison’s V-1710 has an inline Vee cylinder arrangement, and an approximate engine displacement of 1,710 cubic inches, while Wright’s R-2600 is a radial of some 2,600 cubic inch engine displacement.

A piston engine’s power is rated in horsepower available for takeoff, and at a rated altitude. Jet (gas turbine) engines are rated by pounds of static thrust.

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