Where can I find aeronautical blueprints, construction drawings, and/or other plans at the Library of Congress?
The Library of Congress usually does not have aeronautical construction drawings, blueprints and/or plans in its collections unless they are reproduced and included in a book or journal. Searching the online catalog of the Library of Congress, you will be able to identify works about specific airplanes, but usually not the blueprints themselves.
You may wish to contact either the library or the archives of the National Air and Space Museum for more information:
Even if the library at the National Air and Space Museum and/or its archives do not have the blueprints for this/these specific airplane(s), staff at these institutions would be in a better position to advise whether and/or where such plans exist elsewhere.
