Plugging into a new era of flight

July 31, 2012

July 27--OSHKOSH -- Chip Yates is planning to retrace Charles Lindbergh's historic New York to Paris flight.

Sure it's been done. But in an electric plane?

"I want this to be a new era of flight," Yates said Thursday at EAA AirVenture.

Yates isn't the only aviation enthusiast enticed by the idea of leaving internal combustion engines and fuel tanks on the ground and soaring through the air powered by electricity.

Several electric flight innovations, prototypes and experimental aircraft are on display at AirVenture, which ends its weeklong convention Sunday, along with engineers, innovators and researchers who hope one day to make electrically powered flight viable. A two-day electric flight symposium continues on Friday with speakers from NASA's Langley Research Center, Argonne National Labs and electric aircraft designers.

Yates, the entrepreneur behind the world's fastest electric motorcycle, made the 16-minute maiden flight of his electric aircraft July 18 in California. A few days later, he brought to Oshkosh his vision and his plane -- a Long-EZ homebuilt aircraft -- outfitted with a 258 horsepower liquid-cooled, brushless electric motor and 453 volt, 600 amp battery pack.

"We're sort of tired of hearing electric flight is not feasible, and we're tired of people blaming battery manufacturers," Yates said Thursday.

Before he can fly Lindbergh's 3,500-mile nonstop route, though, he and his team must figure out how to recharge the batteries -- in air.

Yates will need to recharge the battery pack five times while recreating Lindbergh's route, which he hopes to do in 2014. He's talking to the Navy about using aerial drones to recharge or possibly a probe from an aircraft, similar to the military's air refueling planes, or even docking with another aircraft in midair, said Mike Beadle, mechanical engineer on Yates' Flight of the Century project.

Bulky batteries

While electric cars and hybrids are now ubiquitous on highways, electric flight is not as far along. Not even close. It's not as simple as using electric car technology in planes. That's because weight is not an issue with motor vehicles.

Electric motors and batteries powerful enough to power a plane are heavy. Sonex, a kit plane manufacturer based in Oshkosh, has spent five years working on its eFlight technology to power one of its Waiex kit planes, first flown in 2010. The electric motor and battery weigh 400 pounds, 100 pounds more than an engine, fuel tank and fuel, said Jeremy Monnett, CEO and general manager of Sonex.

The battery is the biggest stumbling block. Sonex is using the most energy dense cell available and it's equal to only four gallons of fuel. "I think a lot of people got into (electric flight) naively. It's much harder than people think," company spokesman Mark Schaible said at the Sonex display area at AirVenture.

Electric planes will most likely attract sport pilots who use their planes for short rides. Another market could be aerobatic pilots since electric motors provide a much better rate of climb and it doesn't matter if they're flown upside down, since there's no flowing liquids like gas or oil.

"When these systems first come to market, it'll be like the first electric cars. It'll only be the people who can afford them, the ones who are passionate about the technology," said Schaible.

Jetsons' jungle gym

E-volo, a German government consortium, is developing a volocopter powered by batteries. It brought to Oshkosh the Beta version of its prototype. The first version was flown for a few minutes a few feet off the ground last October, the first manned flight of a vertically powered, vertical take-off and landing aircraft.

It looks like a jungle gym for the "Jetsons" kids. With a sling chair suspended inside aluminum tubing and 18 tiny rotor blades on top, the object is getting lots of quizzical stares from AirVenture visitors.

"They're astonished. Not like 'I want to buy one' but 'that's so new,' " said Thomas Senkel, e-volo lead construction engineer and pilot.

Senkel explained that an electric volocopter will be much quieter than a helicopter or gyrocopter powered by a gasoline engine. It will spew no pollution, and with more responsive controls, it will be easier to fly and level off.

E-volo's logo features a dandelion seed, since the volocopter will be designed to move through the air like a twirling dandelion. Within two to three years, engineers expect to create one-seat and two-seat volocopters that can travel at speeds of 60 miles per hour with a minimum altitude of 6,500 feet. The goal is for more than one hour of flight time for each battery charge with a takeoff weight around 1,000 pounds.

Schaible pointed out that gasoline-fueled aircraft are still the only practical way to fly now. Interest in electric flight from the general aviation community will lag until someone figures out how to make an electric plane fly as far and as long while carrying as much weight as those powered by internal combustion engines.

Copyright 2012 - Milwaukee Journal Sentinel