This book surveys all the Soviet/Russian aircraft that either remained "paper projects" (the work progressed no further than the design documents or even merely a design proposal) or were abandoned at the prototype construction stage. Over many years, the authors have unearthed a mass of unpublished material on these aircraft projects including the Isayev/Shevchenko bi-monoplane fighters with retractable lower wings developed in the 1930s, early Soviet jet fighter projects of the Second World War period, and the twin-boom fighters and attack aircraft developed by Semyon M. Alekseyev in the late 1940s. Wherever possible, images of the aircraft are shown, including pictures of models, and line and cutaway drawings from the project documents, giving the readers the maximum available information on Soviet aircraft projects developed over a large time scale. The book is richly illustrated with numerous photos, drawings, and diagrams, as well as color side views of the unbuilt aircraft, which will be of interest not only to the numerous Soviet/Russian aviation enthusiasts but also to scale modelers.