Electric, Small, and Challenging

Dean Sigler Electric Powerplants, Sustainable Aviation 4 Comments

Dr. Ilan Kroo, a professor of aeronautics and astronautics at Stanford and designer of the Swift ultralight hang glider, among others, has a different kind of mission – that of reshaping small aircraft for the greatest efficiency. Lessons learned from light aircraft can be applied on a larger scale – but keeping it simple and light to begin with allows less expensive learning, according to Kroo. The outline for his presentation at the fifth annual Electric Aircraft Symposium in Santa Rosa, California on April 29, 2011 is instructive. He had three major topics, all repeating the title for his talk; “Design Concepts for Small Electric Aircraft.” The first topic emphasized the word, “Electric,” the second, “Small,” and the third, “Design …

Ultra in the Key of E

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

Protoplane, the French manufacturer of the Ultra ultralight two-seater, has big plans for increasing the efficiency of an already efficient aircraft. Their petrol-powered, 450 kilogram (990 pound) all-up weight monoplane can cruise, according to the company, at 220 kilometers per hour (137 miles per hour) on only 12 liters (a little more than 3 U. S. gallons) per hour, achieving 43 miles per gallon.  At slower speeds, the plane can stay aloft for nine hours on its 90 liters of fuel. Protoplane hopes to market the first electric two-seater in 2010, basing the design on improvements in “weight, aerodynamic efficiency, batteries, motors and propellers.” Their web site sets forth Protoplane’s objective. “Making an electric aircraft is very difficult, because one pound …