Greener Aircraft

A revolutionary new airplane, designed for improved fuel efficiency and lower emissions, is on the drawing table. Called the “double-bubble” D8, the new jet has a fuselage that’s wider than a conventional aircraft in order to generate additional lift. Combined with a more aerodynamic nose design, this allows the tail and wings to be smaller and lighter, decreasing overall weight. However, the most notable design change is the engine position, which is moved from the traditional spot underneath the wings to an area on top of the body back by the tail.

On a conventional plane, one of the major forces creating drag comes from the effect of air slowing down as it moves across the top of the body. The D8 reduces this effect by drawing in and reaccelerating the slow air layer. As a result, the new aircraft would use an estimated 37 percent less fuel. With airlines accounting for a larger and larger share of total greenhouse gas emissions, and the demand for air travel increasing steadily, meaningful progress toward lowering pollutants will likely require some fundamental redesigns.

A 1:11 scale concept model has been built and tested in a wind tunnel. The developers are now planning to construct a half-scale prototype. But don’t expect to see the “double-bubble” flying the friendly skies anytime soon. Even if all goes well, it’s estimated that passengers won’t be boarding a D8 until 2035.