Over the next few decades Bartlett drifted into and out of the studio system, helming the prison melodrama "Unchained" (1954) for Warners, and the inspiration for the spoof "Airplane," "Zero Hour" (1957), for Paramount. He limited himself to impersonal producing chores on several MGM films during the 60s, including "Sol Madrid" (1968) and the Bob Hope vehicle, "A Global Affair" (1964). The films on which he filled multiple roles vary from the campy shlock mental asylum melodrama "The Caretakers" (1963), with Joan Crawford as a nasty nurse, to the well-intended but routine racial drama set during the Civil War, "All the Young Men" (1960), pitting a fading Alan Ladd against an ascendant Sidney Poitier. Two of Bartlett's more personal films featured his stepson by actress Rhonda Fleming, Kent Lane, in the leading role: "Changes" (1968), a story of restless youth, and "The Wild Pack" (1972), a tale of homeless orphans in Brazil. As with most of his other films, though, results never quite equalled aspirations.Bartlett followed up with what is unfortunately his best-remembered effort, the boring and rather silly existential quest of a beatified birdie, "Jonathan Livingston Seagull" (1973). Despite having a basis in Richard Bach's best-selling EST-ified book, extensive consumer tie-ins and some stunning aerial cinematography, the film flopped with both critics and public alike. The undaunted indie continued on pursuing his singular vision, though, turning out the sympathetic but stodgy "The Children of Sanchez" (1978) and his last effort, "Comeback" (1982), which told the factual story of an Australian reporter attempting to rescue a Laotian girl in the aftermath of the Vietnam War. Public disputes between Bartlett and star Michael Landon did not help the film (later released to TV as "Love Is Forever"). A highly respected filmmaker in Europe, Bartlett never quite achieved a really outstanding or important film, but his oeuvre does occasionally suggest the chances postwar independent filmmakers could take in terms of subject matter.