Continuity mistake: The plane we see at the end dragging on the ground and taking off is a 707. 707's have four engines: two on each wing. However, the plane we see in the air is a 727. 727's have three engines: one on each side of the rear fuselage and one on the vertical stabilizer. (00:08:10 - 00:27:10)
Continuity mistake: When the 747 crashes into the terminal window, the red stripes wrap all the way around the nose of the plane. In the previous shot, the stripes came to a point and ended several feet back. (00:04:00)
Continuity mistake: After you see all the newspapers talking about the plane, and when you see the drummer on TV who speaks by drum tones, when the drums are handed to him the ends of the sticks are round, but when he looks to HIS left, after the camera changes position, they're not round anymore. (01:04:45)
Continuity mistake: In one of the first establishing shots of the starring Boeing 707, the tailplane livery would suggest that the aircraft is a real-life Trans World Airlines (TWA) airliner with 'Trans American' and 'TA' merely painted on. However, in nearly all subsequent shots (such as that of the aircraft in the air), the tailplane design is noticeably different - the thick red square is now a thin red stripe instead. Also, a further red stripe now extends upwards over the fuselage just before the tailplane. (00:08:05 - 00:14:00)
Continuity mistake: In the scenes on the plane, the camera angle showing the seats down the left side (on the plane's right side) change from 3 seats to 2 seats, then back again. This is evident because the 2 black passengers who speak 'Jive" are seen in their seats with both 3 and 2, and not because it goes from Coach to First Class.
Continuity mistake: At the end when Elaine and Ted are standing on the runway kissing, the first shot of their plane can be seen in the background and it appears to be up off the runway on its landing gear, not lying flat on its belly. When Otto starts the engines to take off and the camera focuses back on the plane, the plane is back on it's belly like it was when it landed.