It’s called distributed propulsion, and it’s one of several avenues being explored to develop low-emission airplanes.
The planes aren’t flying just yet — the wings are actually being tested on trucks — but they could represent the future of green flying, according to a New York Times article.
The Times reports:
Commercial aviation accounts for about 2 percent of the global total of carbon dioxide emitted annually by human activity, or a little less than is produced by Germany.
Air travel has become more efficient since its start, but the industry is projected to more than double in the next 15 years and could grow to contribute one-fifth of total global emissions.
Aviation emissions were excluded from the Paris climate accord, but the International Civil Aviation Organization [ICAO] told the Times that it expects to “approve certification standards next year that would limit [carbon dioxide] emissions for new aircraft.”
There have been incremental improvements to fuel consumption in airplanes and jet planes simply by making modifications to reduce drag. Overall, though, the basic design of a plane is the same across models.
Developers like NASA are working on some revolutionary designs, like wings that can respond to real-time weather conditions, and the distributed propulsion system that takes some of the weight and thrust from the engines and converts it to many smaller electric motors.
NASA’s design relies on electricity and uses batteries, which have limitations. The researchers are studying the use of “hybrid turbine-electric systems that might use batteries and a single jet engine to generate electricity for the motors,” according to the article.
The Times reports that Boeing is working on several wing and fan variants that would greatly reduce drag.
Although the LeapTech truck-plane can’t fly, it simulates takeoff and landing by traveling 70 mph down a runway. One of the researchers told the Times that sensors measure “lift, drag, motor efficiency and aerodynamic performance,” just like a real plane.
The next step will be to put the distributed propulsion on a small plane. It will be limited to short flights because of the batteries.
The researchers expect hybrid turbine-electric systems to be in use in 20 years, even on large commercial planes.