Lifting body airliner

Philip Greenspun's Weblog 2019-06-12

One of the topics that we cover in the Aerodynamics lecture within our MIT Private Pilot Ground School (link to all of the slides and videos) is the industry inertia that results in all airliners looking more or less the same: tube plus wings.

It turns out that this is not an efficient way to build an airplane. The most fuel-efficient approach is a “lifting body” in which the fuselage is optimized to produce lift. With aluminum-and-rivet construction these probably haven’t made sense commercially, but now that airliners (e.g., Airbus A350 and Boeing 787) are made from composites, the complex shapes of a lifting body airliner might not be dramatically more expensive to fabricate.

Who is crazy enough to try to turn the academic dream into a commercial reality? KLM:

The Dutch national airline announced that it is helping fund the development of the Flying-V, a lifting-body-esque flying wing aircraft designed by Delft University of Technology student Justus Benad.

The designers say the Flying-V will use 20% less fuel than an Airbus A350 while carrying about the same number of passengers, 314. Roelof Vos, project leader at TU Delft, highlights the Flying-V’s efficiency as an important component of an industry eventually headed toward electric propulsion. According to CNN, Vos claims that ”aviation is contributing about 2.5% of global CO2 emissions, and the industry is still growing, so we really need to look at more sustainable airplanes. We cannot simply electrify the whole fleet, as electrified airplanes become way too heavy and you can’t fly people across the Atlantic on electric airplanes—not now, not in 30 years. So we have to come up with new technologies that reduce fuel burn in a different way.”

These folks are taking the long view:

A flying prototype is promised by October 2019, but the design isn’t expected to enter service until 2040.