January 31, 1971
Episode 1 of Season 4 premiered on January 31, 1971
March 28, 1971
Episode 2 of Season 4 premiered on March 28, 1971
April 18, 1971
Episode 3 of Season 4 premiered on April 18, 1971
June 20, 1971
Episode 4 of Season 4 premiered on June 20, 1971
September 26, 1971
Episode 5 of Season 4 premiered on September 26, 1971