Before looking forward, the structural significance of the trend towards the rear-mounted engine must be considered. The reason for this trend stems from the need to obtain increased overall efficiency. The advent of the jet engine first of all made it possible to bring the engines inboard into the root, as on the Comet and Vulcan aircraft, and now, in the interest of obtaining higher aerodynamic efficiency, they have been moved aft towards the tail end of the fuselage. This allows a reduction of wing area, a consequent reduction in tailplane area, an overall reduction in drag and a consequent decrease in fuel consumption for a given performance.