Hikōtei Jidai (飛行艇時代, lit. The Age of the Flying Boat) is a fifteen-page, all-watercolor manga by Hayao Miyazaki, on which his animated film Porco Rosso is based. It was published in Model Graphix in three parts, a monthly magazine about scale models, as a part of Hayao Miyazaki's "Zassou Note" series. Like other manga in this series, "Hikōtei Jidai" is a manifestation of his love for old planes. It is filled with aircraft from the 1920s (heavily modified by Miyazaki) and their technical details, as well as with the men (good-hearted and silly) who love them.
Hikōtei Jidai was published in 1992 by Dainippon Kaiga (ISBN 4-499-20595-6). It is a book of about 60 pages, includes the 'Porco Rosso' manga (15 pages total), several airplane vignettes, resin-kit models of aircraft, photos of some real counterparts of the floatplanes which appeared in the film, and some interviews with Miyazaki regarding airplane model kits.