In one episode of the Thunderbirds, Brains under the guise of Hyram J. Hackenbacker, designed a new airplane for the British Airways. It was called the Skythrust. It was designed with safety in mind. The shuttle thing on the back is really an ejectable fuel tank so if the plane has to make an emergency landing, say without landing gear, it can eject the tank lessening the chance of fire and explosion upon hitting the ground.