I never watched this show consistently when I was in elementary school...so the question is this:
When did Hawk find his older brother, and the episode and season it occurred (as suggested by reading the overview of the series, and the mention of a 4th season on a different network)?
Saint John (or St. John) was found in the beginning of the 4th season, which aired on USA Network in Spring-Summer of 1987. The episode was called Blackjack, and "featured" the elimination of the entire original cast (Dom and String both died, Archangel was "reassigned," and no mention was ever made of Caitlin's fate.) The 4th season is considered by most Airwolf fans (including myself) as a complete and utter abomination, for the reasons stated above. (Information from Wikipedia's article on Airwolf).
"Has anybody ever told you you have a SERIOUS IMPULSE CONTROL PROBLEM??"