It was believed that “Rockets Or Romance” was the final episode of Hogan's Heroes. This episode which was aired on April 4, 1971, ends with the prisoners putting their gyroscopic sabotage plan into action, right when Klink is about to launch a rocket toward London. Instead, the rocket heads to Burkhalter’s neighborhood, roughly in the area of his house.
As per Avclub.com, “Rockets Or Romance” was not the last episode filmed for Hogan’s Heroes’ sixth season. In keeping with the way TV was made at that time, “Rockets Or Romance” was one of a batch of episodes written and shot as part of the regular production cycle, then scheduled for broadcast after they were in the can.
Hogan’s Heroes wasn’t serialized, episodes could run in any order, so the producers and the network decided later which finished episode would make the strongest season première, and would slot the rest according to the time of year, the expected audience, and other largely practical reasons.
Anecdotal sources suggest that there was no final episode. The show was still very popular in its final season on the air. It was canceled with little notice while on hiatus from filming between seasons.
CBS executives felt the network lineup had become too ruralized and wanted to revamp their offerings to appeal to a more urban crowd. It is reported that "any show with a tree in it" was given the axe. Shows such as "Beverly Hillbillies" and "Green Acres" were more of the mold this philosophy was aimed at, but "Hogan's Heroes" somehow ended up in the same net, despite consistently high ratings.
There are 168 episodes in the Hogan's Heroes Series starting on September 17, 1965 and ending on April 4, 1971.
The quick wits and charisma of the good guys played by Bob Crane and Richard Dawson, not to mention the brilliant bumbling of Werner Klemperer and John Banner, played a large part in the series' success.
Check out incredibly true facts about 'Hogan's Heroes' at Metv.com.