Hybrid Airliners Could Be In Our Future

Sugar Volt:  Nick Kaloterakis

SUGAR VOLT, BOEING

Target Date: 2035
The best way to conserve jet fuel is to turn off the gas engines. That’s only possible with an alternative power source, like the battery packs and electric motors in the Boeing SUGAR Volt’s hybrid propulsion system. The 737-size, 3,500-nautical-mile-range plane would draw energy from both jet fuel and batteries during takeoff, but once at cruising altitude, pilots could switch to all-electric mode. At the same time Boeing engineers were rethinking propulsion, they also rethought wing design. “By making the wing thinner and the span greater, you can produce more lift with less drag,” says Marty Bradley, Boeing’s principal investigator on the project. The oversize wings would fold up so pilots could access standard boarding gates. Together, the high-lift wings, the hybrid powertrain and the efficient open-rotor engines would make the SUGAR Volt 55 percent more efficient than the average airliner. The plane would emit 60 percent less carbon dioxide and 80 percent less nitrous oxide. Additionally, the extra boost the hybrid system provides at takeoff would enable pilots to use runways as short as 4,000 feet. (For most planes, landing requires less space than takeoff.) A 737 needs a minimum of 5,000 feet for takeoff, so the SUGAR Volt could bring cross-country flights to smaller airports.—Rose Pastore