The Longjohn Flap autobiography, "Never Have Your Dog Stuffed: and Other Things I've Learned", Alan Alda says that for this episode, he borrowed the structure from "La Ronde". "In my version, the object that's passed from couple to couple is a pair of long johns during a cold spell in the Korean winter." The Longjohn Flap "The Longjohn Flap" was episode #19 of the first season of the TV series "M*A*S*H". It originally aired on February 18, 1973 and was the first episode of "M*A*S*H" to be written by series star Alan Alda. In the middle of a cold snap, Hawkeye receives a
Things Which Have Never Yet Been Done was shot with a handheld camera by the episode's director, TJ Scott, with Maslany and Outerbridge improvising the dialogue and use of props. The subsequent shot of the barn on fire was created by the visual effects company Intelligent Creatures. The title of the final two episodes, "Things Which Have Never Yet Been Done" and "By Means Which Have Never Yet Been Tried", are taken from a Francis Bacon quotation in his philosophical work "Novum Organum": "It would be an unsound fancy and self-contradictory to expect that things which have never yet been done can be done except by means