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 of mogas stores the same energy as 54 pounds of the best space designed Lithium-Ion battery cells ; So Ultra-e focus[es] on the objective of running 280 km (174 mi) at 160 km/h (100 mhp) with 21 kWh, equivalent to …