The Comco Ikarus C42 is a popular ultralight aircraft in Europe, now being tested with a unique hybrid power system. Anton (Toni) Roth was an early adapter, putting small electric motors on a variety of ultralight aircraft over the past several years. These have been the lightest of machines powered by Eck/Geiger motors, controllers and batteries. His latest is a hybrid conversion of the popular C42, two-seat ultralight which normally flies on a Rotax engine, as do most European ultralight craft. In this case, Roth has mounted a Swiss single-cylinder four-stroke engine behind the pilot’s seats driving a Geiger generator which in turn powers a Geiger HP-55D motor on the nose, delivering up to 73 kilowatts (97 horsepower) and providing a rate of climb of five to six meters per second (584 to 1181 feet per minute) – an impressive performance for small aircraft. The engine, sipping a mere five liters (1.32 U. S. gallons) per hour, enables the generator …