The CAFE Foundation on Thursday released the final results from its NASA Green Flight Challenge, held two weeks ago in California. The figures show a "profound difference" in energy use between the two electric-powered winners and the runners-up, which were powered by gasoline and hybrid engines, according to Dean Sigler, posting at the CAFE blog. Those differences are "surprising," Sigler said, since all the competitors were "extremely clean" motorgliders, with lift-to-drag ratios between 25-to-1 and 35-to-1. Possible explanations for the differences could be the low cooling drag for electric aircraft and the overall efficiency of the electric motors, Sigler said. Detailed statistics for the four competing aircraft, including fuel consumption, time, and distance, are now posted on the CAFE blog.
This is a companion discussion topic for the original entry at https://www.avweb.com/news/green-flight-challenge-final-results