Character mistake: Carl, carrying his gun, goes up the outside staircase before entering Frank's apartment. When he encounters the frightened cleaning woman, he flashes his F.B.I. badge at her to identify himself. However, he only shows her the back of the black I.D. wallet, which has no markings on it.
Factual error: Just after Carl finds out that Frank has escaped through the plane's lavatory, there is a shot of the plane landing. The plane shown is an Airbus A310, which didn't enter service until 1983, 14 years later. Also, TWA never operated the A310. Later, when Frank climbs out from the landing gear as the plane is taxiing, the aircraft is a Douglas DC-8. (02:00:53)
Continuity mistake: When he pretends to be a doctor, and a he has to give advice on what to do with this patient, a woman gives him some kind of tool. He holds it in his hands, and towards his face, in a 'thinking' pose. Then the camera changes and the object is suddenly gone. The camera then jumps back to the previous position where he had the tool, but it's also gone in that frame. He's now just having his arms crossed.
Factual error: No airport in the world has runway 44. They are numbered 01 to 36.
Factual error: When Carl looks at a map over Europe, the borders of the countries are incorrect at the time: Germany is shown as one country, but it was divided into east and west in the sixties. Czechoslovakia was one country in the sixties, however it was divided into Czechia and Slovakia on the map, as it was at the time the movie was made.
Continuity mistake: After Frank Jr. receives some checks for his 16th birthday he hugs his dad. Jr.'s head rests on his dad's right or left shoulder, depending on the angle.
Answer: It lasts several months. The stewardesses were juniors and seniors from the University of Arizona, whom he fake-recruited for a PR project for Pan-Am (they were not supposed to be real stewardesses, but dress like them and be photographed in various European capitols). Frank was frequently being asked where his "crew" was, so he thought it would lend him credibility.