Clifford C. Clavin, Jr. is a fictional character on the American television show Cheers played by John Ratzenberger. A postal worker, he is the bar's know-it-all and was a contestant on the game show Jeopardy! Cliff was not originally scripted in the series' pilot episode, "Give Me a Ring Sometime", but the producers decided to add a know-it-all character and Ratzenberger helped flesh it out. The actor made guest appearances as Cliff on The Tortellis, St. Elsewhere, Wings, and Frasier.

"Fear of Flying" is the eleventh episode of the sixth season of the American animated television series The Simpsons. It was first broadcast on the Fox network in the United States on December 18, 1994. In the episode, the family attempts to go on a vacation but soon discovers that Marge is afraid of flying.