An handwriting note from Ernest Lehman.

Ernest Lehman (1915-2005) is the writer of North by northwest.

Mini Biography : One of the most critically and commercially successful screenwriters in Hollywood history, Lehman grew up on Long Island, graduated from NY's City College. One of his first jobs was as a copywriter for a Broadway publicist. This experience would later be reflected in his novel and screenplay, "Sweet Smell of Success." He also worked as a radio comedy writer, and as editor of a financial magazine. He freelanced short stories for the likes of Collier's magazine and one of these fiction piece 'The Comedian' led to his first job in Hollywood as a screenwriter for Paramount in the mid 1950s. Nick Roddick, in Dictionary of Literary Biography, praised Lehman as "a champion of the well-crafted, what-happens-next screenplay." Served as president of the Writers Guild of America from 1983-85. (from IMDB)

The note (source) is about the plane chase scene and the crash in the oil tanker.

Even the greatest scenes begin with little notes !