CCO - Creative Commons (CC0 1.0) This media is in the public domain (free of copyright restrictions). You can copy, modify, and distribute this work without contacting the Smithsonian. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer CCO - Creative Commons (CC0 1.0) This media is in the public domain (free of copyright restrictions). You can copy, modify, and distribute this work without contacting the Smithsonian. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer CCO - Creative Commons (CC0 1.0) This media is in the public domain (free of copyright restrictions). You can copy, modify, and distribute this work without contacting the Smithsonian. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer CCO - Creative Commons (CC0 1.0) This media is in the public domain (free of copyright restrictions). You can copy, modify, and distribute this work without contacting the Smithsonian. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer CCO - Creative Commons (CC0 1.0) This media is in the public domain (free of copyright restrictions). You can copy, modify, and distribute this work without contacting the Smithsonian. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer CCO - Creative Commons (CC0 1.0) This media is in the public domain (free of copyright restrictions). You can copy, modify, and distribute this work without contacting the Smithsonian. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer CCO - Creative Commons (CC0 1.0) This media is in the public domain (free of copyright restrictions). You can copy, modify, and distribute this work without contacting the Smithsonian. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer CCO - Creative Commons (CC0 1.0) This media is in the public domain (free of copyright restrictions). You can copy, modify, and distribute this work without contacting the Smithsonian. For more information, visit the Smithsonian's Terms of Use page. IIIF provides researchers rich metadata and image viewing options for comparison of works across cultural heritage collections. More - https://iiif.si.edu View Manifest View in Mirador Viewer

The CD-12 development history extended over several years, and involved a number of well regarded figures in the aircraft industry. Beginning in 1915, using the design skills of Charles Kirkham, and in competition with Wright which was licensed to build the popular Hispano-Suiza engine in the United States, Curtiss, then led by John North Willys, began development of the K-12 engine.

A 224 kW (300 hp) engine weighing less than 454 kg (1,000 lb) was a great challenge. So it was not surprising that the aluminum monoblock and several other advanced features, including the reduction gearing, presented substantial problems, appearing in various stages of the development process.

Unable to overcome these difficulties, Kirkham left Curtiss in 1919. However, development continued under Arthur Nutt, and a derated CD-12, without the reduction gearing of the K-12, resulted in 1921. This further developed into the 1922 D-12, a successful engine for both racing and fighter aircraft.

 Display Status

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Object Details
Date Circa1921 Country of Origin United States of America Type PROPULSION-Reciprocating & Rotary Manufacturer Curtiss Aeroplane and Motor Company
 Physical Description Type: Reciprocating, V-type, 12 cylinders, water-cooled Power rating: 242 kW (325 hp) at 1,800 rpm Displacement: 18.8 L (1,145 cu in.) Bore and Stroke: 114 mm (4.5 in.) x 152 mm (6 in.) Weight: 308 kg (680 lb) Dimensions Overall: 39 1/4 x 22 1/8 x 63in., 680lb. (99.7 x 56.2 x 160cm, 308.4kg)
 Materials Aluminum, Steel, Rubber, Preservative coating, Phenolic
 Inventory Number A19270005000 Credit Line Transferred from the U.S. Navy Department, Washington, D.C. Data Source National Air and Space Museum Restrictions & Rights Open Access (CCO)
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