Question: Name the American actor, best known for his role as Captain B.J. Hunnicutt in a television series which included a 2-episode story arc where we see the departure of Captain Trapper and his replacement by this new Captain? 
Sentence (from "Welcome to Korea"): First aired on September 12, 1975, the series' first 60 minute episode (double the normal time) was most notable for its off-screen departure of the character of Captain Trapper John McIntyre (played by Wayne Rogers), and his replacement by the freshly drafted Captain B.J. Hunnicutt (played by Mike Farrell).
Relevant evidence: Yes