The Hughes Tool Company series (1912-1990) encompasses the administrative, financial, and legal management of Hughes Tool Company. Materials within the series depict Howard Hughes' control of the company; his film, aeronautics, electronics, and real estate ventures; and his lawsuits and United States Senate hearing. The series also includes research reports on the corporate history of Hughes Tool Company and its subsidiaries, copyright histories for films Hughes produced, and correspondence from Hughes' associates searching for reels of Hughes' films domestically and internationally.

Materials contain photographs of the Hughes XF-11 prototype military reconnaissance aircraft. Howard Hughes piloted the two XF-11 prototypes built: in July 1946, Hughes crashed the first XF-11 in Beverly Hills, California; in April 1947, Hughes successfully flew the second prototype at high speeds and at high altitudes. However, the United States Air Force abandoned the controversial project, and in August of 1947, Hughes was called to testify before the Truman Committee in the U.S. Senate about the failures of the program.