Reported to have been intended as the swan song for the character of Margaret, as she finally got married to the career military man of her dreams, flying off with him to Tokyo, leaving the dead-end affair with Frank Burns behind. However, actress Loretta Swit came back for Season 6 and Larry Linville did not, so Margaret's character continued to be fleshed out and Burns was replaced by Maj. Charles Emerson Winchester III.
Larry Linville left the show because he felt that the character of Frank Burns was too one-dimensional, and that they'd done all they could do with it.
Although frequently mentioned and referred to by Margaret Houlihan, the character of LTC Donald Penobscott only appears in person in the series twice, and was portrayed by two different actors: Beeson Carroll in "Margaret's Marriage," and Mike Henry in "The M*A*S*H Olympics."
Final Appearance of Larry Linville as Major Frank Burns, although his departure took place off screen during the subsequent episode and was a major factor in the introduction of his replacement Major Charles Emerson Winchester III as played by David Ogden Stiers, although Linville along with other departed MASH regulars would appear in flashbacks in Season 7