Blended-wing-body aircraft: A historical perspective

A blended-wing-body aircraft, BWB in short, is an innovative radical configuration applicable to the conceptual design of future large transport aircraft. Realization of the BWB aims at a substantial step in the continuous process of improving their flight performance, reducing atmospheric emissions, and minimizing environmental noise production due to civil aviation. The BWB belongs to the category of flying wings, an airplane layout with high aerodynamic efficiency that until recently has been practiced operationally for long-range bomber aircraft only. Applications of the BWB are foreseen primarily in high-subsonic jetliners with a capacity between 250 and 1000 seats. The general arrangement of a BWB does neither feature a discrete fuselage body nor an empennage. The crew, passenger seats, cargo, and luggage compartments are integrated in a thick lift-generating central wing segment with a large center body chord and approximately equal span. The narrow-chord outboard wings of recently proposed BWBs together form a conventional moderately loaded high-aspect ratio swept wing.
Advanced designs for a BWB intended for commercial application were developed during the last decennium of the twentieth century in the United States by teams formed by NASA, the industry, and universities. Although various proposed concepts have quite different characteristics, they consistently indicate that a BWB can have acceptable flying qualities, improve the aerodynamic efficiency by 25%, and the fuel efficiency and CO2 emissions by 35% relative to the conventional TAW. Further refinements of the concept, wind-tunnel experiments and low-speed flights with a remotely controlled flight test vehicle after the year 2000 have confirmed the promises of the advancements obtained by the project study teams.