Thursday, December 11, 2008

Battery Powered Airplane



Take your everyday metal moni motoglider, trick it out with a custom battery pack and you've got the ElectraFlyer C, a small electric airplane that debuted at the AirVenture show in Oshkosh, Wisconsin, last week.

The plane, which received its airworthiness certificate in April, features a 5.6 kWh lithium battery with a projected life cycle (the number of times it can be depleted and recharged) of 1,000 cycles. The battery has a max weight of 78 pounds and can be custom-built to fit the available space in an airplane. It provides juice for a motor driving a 45-inch superlight PowerFin propeller made of a foam core surrounded by an outer shell of carbon fiber and glass fabric.

Once in the air, the ElectraFlyer C cruises at 70 miles per hour. Top speed is 90 mph and the stall speed is 45. The plane can fly for 90 to 120 minutes before the battery needs recharging. When the battery winds down, just plug it into a 110V outlet -- your house is full of them -- and you're good to go in just more than six hours. Bump the voltage to 220 and you're flying again in two hours.

The people at Electric Aircraft Corporation say the small plane carries some big benefits. The motor is nearly silent, which means no earplugs for pilots, and brings the potential for flying into new sites. And then there's the a dramatic improvement in what the company calls "neighbor relations" -- no droning engines to drive them nuts. Electric motors don't produce a lot of soot or pollution, and overhauls are a snap. And by combining this motor with the ElectraFlyer's slow turning propeller, you've got a flight that is practically vibration free.

But the most compelling sell is an economic one: The company estimates that "refueling" the plane with a full charge of the battery will cost, on average, a whopping sixty cents.

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