Doctor to Stewardess: "We must get these passengers to a hospital right away."
Stewardess: "A hospital!? What is it, Doctor?"
Doc: "It's a building full of sick people..."
The scene in the cockpit where the doctor says everyone who ate the fish for dinner is going to get violently ill. Peter Graves looks over at his dinner plate, where a perfect fish skeleton is all that's left of his meal. Followed by the symptoms...
Otto the auto-pilot!
(When he went soft, stewardess Elaine
had to personally and intimately reinflate him
using the emergency inflation tube
located just below his belt buckle.)