Personal, 'green' airplanes propel forward

The idea of personal planes may conjure up dark visions of Blade Runner, but the first batch of two-seater aircraft to fly on electricity rather than fossil fuels could reach more than a dozen buyers by year's end.

This electric glider could become the greenest two-passenger personal aircraft on the market.

(Credit: Pipistrel)

And if some fans of experimental air travel have their way, that's a step closer to a gridlock-free future when relatively ordinary folks will hop to work in small, carbon-neutral planes.

A cozy crowd of several dozen engineers, venture capitalists, and members of clean-tech companies plotted the potential at the Electric Aircraft Symposium held Saturday in San Francisco, sponsored by Foundation Capital and held by the CAFE Foundation, a nonprofit aiming to advance personal air travel. CAFE stands for Comparative Aircraft Flight Efficiency.

The meeting included Ivo Boscarol, CEO of Pipistrel, which by the end of this year is set to deliver the first commercially produced, two-passenger electric aircraft to customers. The Slovenian company's Taurus Electro can climb to 6,000 feet after taking off on a 30-kilowatt motor. Recharging the glider's lithium-polymer battery is meant to take about as long as powering a cell phone. Depending upon the weather and skills of the pilot, the glider can travel 1,000 miles in a day.

"I'm sure that electric power everywhere will be the substitute for internal combustion fuel engines," Boscarol said. "First, you must develop aircraft that needs so little power that electricity is efficient."

The glider weighs little more than 700 pounds and costs $133,000, only about one-third more than the electric Tesla Roadster, a hot toy for billionaires.

Pipistrel's customers include Formula One driver Pedro de la Rosa. But even Google co-founder Larry Page, who attended the forum, might have to wait to purchase the electric Taurus if he were interested. It is in the final stages of test flights and will be manufactured in a limited run this year. And in the United States, the Federal Aviation Administration would prevent people from flying the glider under the same rules as light sport aircraft.

However, FAA rules could change, possibly within the next year. The Experimental Aircraft Association announced Saturday that it has filed a request for the FAA to change how it classifies electric aircraft. If the group's petition succeeds, the U.S. market could open up for other electric craft on the horizon.

"Changing the way we move through the environment is critical to this planet," Experimental Aircraft Association representative Craig Willan told the crowd. "This is the first step to ensuring not only government compliance but also assistance."

The FAA usually takes about six months to make such decisions, according to agency inspector Matt DeSeelhorst.

Sustainable air travel
Aircraft emissions, including carbon dioxide, nitrogen oxides, and methane, account for up to 3 percent of the world's greenhouse gas pollution, according to the Intergovernmental Panel on Climate Change. Although the bulk of that comes from hulking commercial jets, light aircraft continue to use leaded fuel, which the government moved to phase out in passenger cars 35 years ago.

Larry Page, who with fellow Google co-founder Sergey Brin rents parking space for private jets at NASA's Moffett Field, checks out lightweight motors designed by Greg Stevenson.

(Credit: Elsa Wenzel/CNET)

Making air travel more sustainable will be tricky in the United States, where the number of aerospace engineering graduates has plummeted by 57 percent since 1990, said Brien Seeley, CAFE Foundation president.

By contrast, support for light aircraft development is strong in the European Union, which contributed about 20 percent of the $2.3 million that Pipistrel spent creating the Taurus Electro, according to Boscarol.

The U.S. Defense Advanced Research Projects Agency has supported the development of lightweight, stealth aircraft, but its innovations aren't necessarily reaching the civilian level soon. The federal government yanked its support more than two years ago for NASA's personal aircraft research group.

However, NASA is spending $2 million over five years on contests held by the CAFE Foundation and backed by Boeing Phantom Works. Last August, the inaugural NASA Personal Air Vehicle Centennial Challenge handed out $250,000 in prizes rewarding the efficiency and noise reduction of personal air vehicles. The top place went to the owner of a Pipistrel Virus motorglider.

This year's contest will include its first Green Prize of $50,000 for a craft that achieves at least 100 miles per hour and the equivalent of 100 miles per gallon. Renamed the General Aviation Technology Challenge, the contest will dole out a total of $300,000.

Supporters of such competitions hope they can convince people that air travel could become the greenest form of transportation.

"It will change society, the way we work, the way we live, the way cities grow," said Richard Jones, a technical fellow at Boeing Phantom Works.

The research group is designing a plane-car hybrid to travel up to 300 miles at a time. Jones believes that by 2030, precision navigation systems could make it easier to pilot a compact plane than to drive a car.

Because the Taurus Electro is a glider, the controls are relatively simple. The most a pilot would need is a GPS and a gliding computer, according to Pipistrel.

(Credit: Pipistrel)

"People will probably be reading a newspaper rather than flying the vehicles," he said.

The trick is equipping aircraft with a brain as smart as a seagull's, said NASA aerospace engineer Mark Moore, who headed NASA's now-shuttered personal aircraft research group. And responsive tactile controls, such as steering mechanisms that resist a hand's wrong move, can prevent human error.

Coming closer to that goal is the Garmin G1000 Synthetic Vision System, noted several attendees. Released earlier this month, it enables pilots to view topographic details even in foggy conditions within a Google Earth-like interface.

Hertz Rent-A-Plane?
CAFE Foundation's Seeley displayed a mock-up interface that would draw a virtual pathway in the sky to keep a pilot on track.

"This is how we're gonna get eventually to Hertz Rent-A-Plane," he said.

However, developing batteries and engines light enough for small commuter aircraft remains tricky. Pipistrel is working with the University of Stuttgart in Germany to design hydrogen-fuel-cell-powered aircraft, as is Lange Aviation with the German Aerospace Centre, but results remain distant.

Others are working to improve upon readily available lithium-ion batteries. Yi Cui, a Stanford assistant professor of engineering, is exploring the use of nanowires as battery electrodes to pack more power into a smaller package. Unpublished results from lab tests have been promising, said Cui, who hopes to commercialize the technology within the next five years.

The secretive EEstor, also working to improve energy density in batteries, presented at last year's Electric Aircraft Symposium. In January, Lockheed Martin announced plans to buy EEstor's ultracapacitors, which reportedly weigh one-tenth less than lead-acid batteries but hold 10 times more energy.

Self-funded start-up Windward Performance of Bend, Ore., is working to build a light aircraft that would fly on a battery at 15 kilowatts per hour for about $1.50 per charge.

"This would be a completely off-the-grid and off-oil passenger plane," said creator Greg Cole, who hopes to raise $2 million. His redesign of the Sparrowhawk sailplane is known as the first with wings and fuselage made of all carbon composite materials.

Hybrid airplanes that blend electric and biofuel engines could be the bridge to off-grid, oil-free air travel, according to some proponents of personal, "green" air travel.

Engineer Greg Stevenson displayed a two-cycle diesel engine that weighs 18 pounds and can run on biofuels. "It's as omnivorous as it's gonna get," he said.

At a fraction of the 200-pound weight typical of commercial diesel engines, that type of innovation might help pave the way for powering hybrid, lightweight biofuel/electric aircraft.

The Taurus Electro could be the first electric aircraft of its kind in serial production, reaching buyers by the end of the year. Click photo for more pictures of green aircraft.

(Credit: Pipistrel)