Already proving its ability to climb at a great rate on its own, the Siemens-powered Extra 330LE towed an LS-8 sailplane to 600 meters (1.968 feet) in a mere 76 seconds.  This alone could be a gift to soaring. Sitting at the controls of a sailplane being towed aloft behind a conventionally-powered tow plane proves taxing, for the many minutes it takes to gain a release height of 2,000 or 3,000 feet can seem somewhat endless.  It’s also expensive for the gliding club or commercial operation.  The soaring club in which your editor was a member calculated the average tow for a Piper Pawnee or Cessna AgWagon consumed around 2.7 gallons to 3.0 gallons of $5.00 a gallon avgas.  Twenty …