Graves had a long run on Mission: Impossible, and appeared in Stalag 17. The most recent thing that I remember him being in was Seventh Heaven, when he played that preacher guy's father.
But a lot of people from my generation are going to know him best as Captain Ouver, the airline captain in the classic 1980 slapstick comedy Airplane!
So before you go looking for it, I've done the work for you. Here is Graves as Captain Ouver, asking Joey such things as "You ever seen a grown man naked?"
Farewell Mr. Graves, and thanks for the many thrills and laughs.