Corporal "Radar" O'Reilly was a key character in Alan Alda's "Hawkeye" Pierce was the main character of M*A*S*H, with the role still being the actor's most acclaimed.
There were plenty of other audience favorites, such as Wayne Rogers' Trapper or Loretta Swit's Major "Hot Lips" Houlihan. Corporal "Radar" O'Reilly (Gary Burghoff) was another, with the character being so named for his almost superhuman hearing and always sensing when his commanding officer needed him. Radar's boyish innocence was also a good contrast to more cynical of the 4077th too. However, he exited during M*A*S*H season 8, as Burghoff was burned out by the show's schedule and being away from his family for long periods. In the series itself, Radar's exit was explained as being given a hardship discharge so he could go back to his family farm, and help his mother following his uncle's death.
Gary Burghoff Connected The MASH Movie & Show
While several actors from the M*A*S*H movie played guest roles on the series, Burghoff is the only actor to play the same role in both. There are differences between his portrayals, however. The Radar seen in Altman's M*A*S*H was a darker, more opportunistic character, but while the actor initially carried this over to the show, he decided to make the TV version more naive.
On the series, Radar was intended to be around 18 - despite the fact Burghoff was almost 30. His youthful appearance helped conceal this, but when he departed in M*A*S*H's "Good-Bye Radar" episode, Burghoff finally took the hat he wore throughout the series, which hid his receding hairline. Burghoff felt this was a good visual to display how the character went from a boy to a man during the war.
Why MASH's Spinoffs Didn't Work
While long-running medical drama Trapper John M.D. followed the titular character decades after the war, the show's producers claimed it was based on the book, not the M*A*S*H series. Following M*A*S*H's finale episode, two spinoffs were produced. AfterMASH ran for two seasons and followed Colonel Potter, Klinger and Father Mulcahy as they adjusted to civilian life. Despite its initial ratings success, it was met with poor reviews and is now considered one of the worst spinoffs ever produced. Burghoff's Radar made a guest appearance on AfterMASH, followed by the TV movie W*A*L*T*E*R, where he becomes a policeman. W*A*L*T*E*R was intended to launch another series, but was also badly received and didn't make it past the pilot stage.