On this Friday, Charles F. Bolden Jr., the NASA administrator, announced plans for an all-electric airplane designated as X-57 at a conference of the American Institute of Aeronautics and Astronautics in Washington.
The X-plane designations are handed out by the United States Air Force for experimental, cutting edge aircraft starting with the X-1 that broke the sound barrier in 1947. NASA’s last X-plane effort, more than a decade ago, was the X-43A, a pilotless black dart that accelerated to almost 7,000 miles per hour, which set the record for a jet-powered aircraft.
This latest design is believed to be one big part of the agency’s efforts to make aviation more efficient and less of a polluter, pushing electric-powered aviation from a technical curiosity and pipe dream into something that might become commercially viable for small aircrafts
“The X-57 will take the first giant step in opening a new era of aviation,” Mr. Bolden declared.
Unlike some of NASA’s earlier sleek, the X-57 will look more like a Cessna, futuristic X-planes. Its cruising speed might hit 175 miles per hour, as fast as the original P2006T and other similar general aviation planes. Its wings, however, will be unique, far skinnier than usual and embedded with 14 motors. The NASA researchers are designing narrower wings that are efficient during cruise flight, powered by two 60-kilowatt electric motors at the wingtips that spin five-feet-wide propellers.
“The problem with traditional aircraft design is you have to size the wings, so that you have safe takeoff and landing speeds and so the wing tends to end up bigger than you need for cruise flight,” said Sean Clarke, co-principal investigator for the project at NASA’s Armstrong Flight Research Center in Edwards, Calif. “That’s a speed (X-57’s 175 miles per hour) that could enable much greater market share for a technology like this.”
The X-57 is far from the first electric airplane, and a solar-powered electric airplane called Solar Impulse is currently making a series of flights that will take it around the world. But Solar Impulse cruises at 30 to 40 miles per hour, of which Mr. Clarke said: “I don’t think anyone would classify as high speed.”
The steps taken by NASA will not translate into all-electric cross-country jetliners. Although the new design could cut the operational costs by as much as 40 percent, and is much quieter in terms of electric motors, the design does not overcome the shortcomings of electric propulsion. Its 800 pounds of batteries will replace the rear two passenger seats, and the seat next to the pilot will be replaced with instrumentation, leaving space for only the pilot and no passengers. It can stay aloft for only about one hour.
Mr. Clarke said the technology could be scaled upward for commuter or regional airliners, and NASA is investigating using fuel cells rather than batteries to provide the electricity. But limits in the speed of propeller-driven aircraft means they are unlikely for cross-country airline flights. “I think all-electric would be a stretch for jetliners,” he said.
But the agency hopes the technology can be incorporated into smaller, general aviation and commuter aircraft some years from now. In addition, NASA has four other X-plane projects in the pipeline, part of a 10-year aviation research program proposed by the Obama administration in February. “This will be NASA’s moonshot for aviation,” Mr. Bolden said.