"Flight 104" is the 26th episode of Captain Scarlet and the Mysterons, a British Supermarionation television series created by Gerry and Sylvia Anderson and filmed by their production company Century 21 Productions. Written by Tony Barwick and directed by Robert Lynn, it was first broadcast on 1 March 1968 on ATV Midlands. In "Flight 104", the Mysterons take control of an airliner that is flying Scarlet, Captain Blue and an astrophysicist to a secret conference that has been called to discuss a proposed return mission to the Mysterons' planet, Mars.