The Curtiss O-24 was a proposed observation aircraft designed by Curtiss-Wright.  It was to have been powered by a single Pratt & Whitney R-1340 Wasp radial engine, however, the project was canceled before any aircraft were built.[1][2]
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| Manufacturer designations
 | | Early types |  | 
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 | Model letters |  | 
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 | Model numbers |  | 
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 | "L" series |  | 
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 | "CA" series |  | 
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 | "CR" series |  | 
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 | "CW" series |  | 
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 | "P" series | 
P-200P-202P-212P-218P-219P-222P-223P-224P-225P-227P-228P-229P-232P-235P-238P-239P-240P-241P-243P-244P-245P-247P-248P-249P-250P-251P-252P-253P-254P-255P-256P-257P-259P-261P-264P-268P-269P-272P-273P-274P-275P-276P-277P-278P-279P-280P-282P-283P-291P-292P-293P-295P-296P-297P-298P-299P-302P-303P-304P-305P-306P-307P-509P-517P-518P-538P-539P-541P-545P-551P-558P-565P-586P-588P-592
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 | "X" series |  | 
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| Operator and role | | Civil | | Experimental |  | 
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 | Racers and record |  | 
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 | Airliners |  | 
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 | Utility |  | 
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 | Army | | Ground attack |  | 
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 | Bombers |  | 
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 | Transports |  | 
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 | Fighters |  | 
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 | Observation |  | 
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 | Racers |  | 
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 | Trainers |  | 
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 | Experimental |  | 
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 | Licensed |  | 
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 | Navy | | Bombers |  | 
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 | Fighters |  | 
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 | Observation/scout |  | 
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 | Trainers |  | 
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 | Transports |  | 
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 | Maritime patrol |  | 
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 | Racers and record |  | 
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 | Export | | Bombers |  | 
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 | Maritime patrol |  | 
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 | Fighters |  | 
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 | Trainers |  | 
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| 1 Designation skipped    2 Not built | 
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| USAAC/USAAF sequence (1924–1942)
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| Tri-Service sequence (1962–present)
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| 1 Unconfirmed |