The Pipistrel Taurus G4 made its record-breaking 200 mile flight over Sonoma County last week. The twin-fuselage design carried an unprecedented payload for an electric plane, four passengers and 1,000 pounds of lithium-polymer batteries. And it was pulled by the most powerful electric motor ever put in an airplane, with 194 horsepower, according to Pipistrel officials.
At an average speed of 100 miles per hour, the result was the electric equivalent of 101 miles per gallon of gasoline, or 403.5 "passenger miles per gallon," as the competition multiplied each plane's mileage by the number of seats.
Google sponsored the contest, which provided $1.65 million in prize money to the contestants, including $80,000 for the second place E-Genius plane, an electric two-seater from Stuttgart University in Germany which achieved 375.8 passenger miles per gallon.
The event was organized by NASA and the Comparative Aircraft Flight Efficiency Foundation. The foundation has been running such contests since the gas crisis of the 1970s, when 20 miles per gallon was a major feat for a plane. Technology has changed rapidly.
"Two years ago, the thought of flying 200 miles at 100 miles per hour in an electric aircraft was pure science fiction," said Jack Langelaan, leader of Team Pipistrel-USA.com.
The Slovenian-built Pipistrel was flown by David Morss of Redwood City and Robin Reid of Independence, Ore. Concrete blocks took the place of two additional passengers. The Pipistrel was the only plane in the competition that could hold more than two passengers.
The E-Genius and the Taurus G4 were the main contenders in the event as the only purely electric planes.
In comparison to the electric planes, a gasoline-powered entry from Florida, the Phoenix, was able to achieve 94.3 passenger miles per gallon with two passengers. Like the other planes in the event, the Phoenix is based on a glider. It weighs half what the electric planes do at just 754 pounds when empty.
Aviation journalist Dean Sigler was enthusiastic about what may be a bigger accomplishment than most people realize, even in the aviation world.
"If your car were going 100 miles per hour you wouldn't get anywhere near that efficiency," Sigler said.