The Hell’s Angels sub-series (1922-1965) contains material related to the development, production, and post-production of The Caddo Company film, Hell’s Angels. Both the silent and sound versions of the film are represented in the materials.

Materials include contracts and lawsuits, correspondence, financial, story development, and production and direction records, editing and special effects, aviation logs, and advertising, as well as musical scores for the silent version composed by Adolph Tandler and the sound version composed by Hugo Riesenfeld. Also included are black-and-white photographic prints and negatives and twenty-four miniature airplane models.

The RKO Radio Pictures, Incorporated series (1930-1974) contains material primarily pertaining to development of RKO films during Hughes' ownership of the company. This series primarily features The Conqueror (1956) and Jet Pilot (1957), but also includes material for other films such as His Kind of Woman (1951), and Son of Sinbad (1955). Records include film set and publicity photographs, film advertising and news articles, screenplays, ledgers, and music scores. Corporate materials contain newspaper clippings, copyright documents, administrative correspondence, actor contracts and agreements, and stock information. Also included are scripts, screenplays, and manuscripts collected to draft potential film adaptations. Ledgers contain theatrical screening reports and corporate budgets. Other materials include reports pertaining to the Cold War and film industry blacklisting.