It wasn't shown in my region in 1975
This series got a good deal of publicity back in '75, there were lotsa articles in magazines (even TV Guide) as well as merchandising. I recall seeing Eagle models and action figures of the cast in the local toy/hobby shop.
Unfortunately no one in my area got to see it during its initial run, none of the local TV stations aired it. Back in '75 we had 4 channels: ABC, CBS, NBC, and PBS...and none of these ran it.
It was really frustrating for we sci-fi geeks back then. Seeing the promotion for all this cool stuff and then being denied the opportunity to watch was torture!